interacts_with DB00470?
Role of endogenous cannabinoids in synaptic signaling . Research of cannabinoid actions was boosted in the 1990s by remarkable discoveries including identification of endogenous compounds with cannabimimetic activity ( endocannabinoids ) and the cloning of their molecular targets , the P21554 and CB2 receptors . Although the existence of an endogenous cannabinoid signaling system has been established for a decade , its physiological roles have just begun to unfold . In addition , the behavioral effects of exogenous cannabinoids such as DB00470 , the major active compound of hashish and marijuana , await explanation at the cellular and network levels . Recent physiological , pharmacological , and high-resolution anatomical studies provided evidence that the major physiological effect of cannabinoids is the regulation of neurotransmitter release via activation of presynaptic P21554 receptors located on distinct types of axon terminals throughout the brain . Subsequent discoveries shed light on the functional consequences of this localization by demonstrating the involvement of endocannabinoids in retrograde signaling at GABAergic and glutamatergic synapses . In this review , we aim to synthesize recent progress in our understanding of the physiological roles of endocannabinoids in the brain . First , the synthetic pathways of endocannabinoids are discussed , along with the putative mechanisms of their release , uptake , and degradation . The fine-grain anatomical distribution of the neuronal cannabinoid receptor P21554 is described in most brain areas , emphasizing its general presynaptic localization and role in controlling neurotransmitter release . Finally , the possible functions of endocannabinoids as retrograde synaptic signal molecules are discussed in relation to synaptic plasticity and network activity patterns . Cannabinoid receptors in acute and chronic complications of atherosclerosis . Atherosclerosis is a chronic inflammatory disease that is the primary cause of myocardial infarction and stroke , which occur after sudden thrombotic occlusion of an artery . A growing body of evidence suggests that cannabinoid signalling plays a fundamental role in atherosclerosis development and its clinical manifestations . Thus , CB2 receptors are protective in myocardial ischaemia/reperfusion and implicated in the modulation of chemotaxis , which is crucial for the recruitment of leukocytes during inflammation . Delta-9- DB00470 ( THC ) -mediated activation has been shown to inhibit atherosclerotic plaque progression in a CB2 dependent manner . Although P21554 and CB2 expression has been reported on platelets , their involvement in thrombus formation is still controversial . While several reports suggest that P21554 receptors may have a relevant role in neuroprotection after ischaemic stroke , recent studies show the protective effects in various forms of neuroprotection are not related to P21554 stimulation , and a protective role of P21554 blockade has also been reported . In addition , vascular and myocardial P21554 receptors contribute to the modulation of blood pressure and heart rate . It is tempting to suggest that pharmacological modulation of the endocannabinoid system is a potential novel therapeutic strategy in the treatment of atherosclerosis . For these purposes , it is important to better understand the complex mechanisms of endocannabinoid signalling and potential consequences of its pharmacological modulation , as it may have both pro- and anti-atherosclerotic effects . DB00898 inhibits luteinizing hormone-releasing hormone release by activating the endocannabinoid system . We hypothesized that ethanol ( EtOH ) might act through the endocannabinoid system to inhibit luteinizing hormone-releasing hormone ( P01148 ) release . Therefore , we examined the mechanism by which EtOH and anandamide ( AEA ) , an endogenous cannabinoid , inhibit P01148 release from incubated medial basal hypothalamic explants . In previous work , we demonstrated that EtOH inhibits the N-methyl-D-aspartic acid-stimulated release of P01148 by increasing the release of two neurotransmitters : beta-endorphin and gamma-aminobutyric acid ( GABA ) . In the present work , bicuculline , a GABAergic antagonist , completely prevented the inhibition of AEA ( 10(-9)M ) on N-methyl-D-aspartic acid-induced P01148 release , but naltrexone , a micro-opioid receptor antagonist , had no effect . AEA also significantly increased GABA release but had no effect on beta-endorphin release . Therefore , AEA could inhibit P01148 release by increasing GABA but not beta-endorphin release . Because EtOH and AEA acted similarly to inhibit P01148 release , we investigated whether both substances would affect the adenylate cyclase activity acting through the same GTP-coupled receptors , the cannabinoid receptors 1 ( P21554 -rs ) . AEA and EtOH ( 10(-1)M ) reduced the forskolin-stimulated accumulation of DB02527 , but AM251 , a specific antagonist of P21554 -r , significantly blocked that inhibition . Additionally we investigated whether P21554 -r is involved in the inhibition of P01148 by EtOH and AEA . AEA and EtOH reduced forskolin-stimulated P01148 release , but AM251 significantly blocked that inhibition . Also , we demonstrated that EtOH did not act by increasing AEA synthase activity to inhibit P01148 release in our experimental conditions . Therefore , our results indicate that EtOH inhibits the release of P01148 acting through the endocannabinoid system . Agonist-promoted down-regulation and functional desensitization in two naturally occurring variants of the human serotonin1A receptor . We recently reported two naturally occurring polymorphisms of the human serotonin1A ( P08908 ) receptor : glycine22 --> serine ( Ser22 ) and isoleucine28 --> valine ( Val28 ) in the putative aminoterminal domain of the receptor . To investigate the regulatory properties of these variants , the wild type ( WT ) and variant P08908 receptors were stably expressed in CHO- P04264 cells . WT , Ser22 , and Val28 displayed similar high-affinity binding to [ 3H ] -8-OH-DPAT . Competition experiments with P08908 agonists and antagonists demonstrated similar pharmacological profiles . Receptor agonist-promoted down-regulation was tested by exposure to 100 mumol/L 8-OH-DPAT . After 24-h exposure , WT and Val28 underwent 59.3 +/- 3.9 % and 59.5 +/- 1.4 % reduction in receptor density respectively , whereas the degree of down-regulation was significantly lower for Ser22 ( 21.4 +/- 4.2 % ) . Cell treatment for 24 h with 100 mumol/L 8-OH-DPAT reduced the 5-HT-induced inhibition of DB02527 accumulation by 24.9 +/- 5.1 % for WT and 16.4 +/- 0.8 % for Val28 , but only by 4.8 +/- 3 % for Ser22 . We conclude that the Ser22 variant is capable of attenuating agonist-mediated receptor down-regulation and desensitization . Possible involvement of endocannabinoids in the increase of morphine consumption in maternally deprived rat . Whether adolescent exposure to chronic DB00470 ( THC ) facilitates progression to opioid consumption is still controversial . In a maternal deprivation model ( 3 h daily from postnatal day 1-14 ) , we previously reported that adolescent exposure to chronic THC blocks morphine dependence in maternally deprived ( D ) rats . Owing to the existence of a functional cross-interaction between the opioid and cannabinoid systems in reward , we evaluated if the vulnerability to opiate reward in D rats , may involve an alteration of the endocannabinoid system . Anandamide and 2-arachidonoylglycerol ( 2-AG ) , were quantified in the striatum and mesencephalon of adolescent and adult D and non-deprived ( animal facility rearing , AFR ) rats by isotope dilution liquid chromatography-mass spectrometry . Oral morphine self-administration behavior was analyzed for 14 weeks , 24 days after chronic injection of the cannabinoid P21554 receptor antagonist/inverse agonist , SR141716A ( 3 mg/kg ) for 2 weeks during adolescence ( P01160 35-48 ) . Adolescent D rats exhibited higher basal levels of anandamide than adolescent AFR rats in the nucleus accumbens ( 38 % ) , the caudate-putamen nucleus ( 62 % ) and the mesencephalon ( 320 % ) , whereas adult D rats showed an increase of anandamide and 2-AG levels in the nucleus accumbens ( 50 % and 24 % , respectively ) and of 2-AG in the caudate-putamen nucleus ( 48 % ) , compared to adult AFR rats . Chronic administration of SR141716A to adolescent D rats blocked the escalation behavior in the morphine consumption test . Our data suggest that altered brain endocannabinoid levels may contribute to the escalation behavior in the morphine consumption test in a maternal deprivation model . DB01016 -induced apoptosis is specifically enhanced by expression of the sulfonylurea receptor isoform Q09428 but not by expression of SUR2B or the mutant Q09428 (M1289T) . Q09428 ( Q09428 ) is the regulatory subunit of the pancreatic DB00171 -sensitive K+ channel ( K( DB00171 ) channel ) , which is essential for triggering insulin secretion via membrane depolarization . Sulfonylureas , such as glibenclamide and tolbutamide , act as K( DB00171 ) channel blockers and are widely used in diabetes treatment . These antidiabetic substances are known to induce apoptosis in pancreatic beta-cells or beta-cell lines under certain conditions . However , the precise molecular mechanisms of this sulfonylurea-induced apoptosis are still unidentified . To investigate the role of Q09428 in apoptosis induction , we tested the effect of glibenclamide on recombinant human embryonic kidney 293 cells expressing either Q09428 , the smooth muscular isoform SUR2B , or the mutant Q09428 (M1289T) at which a single amino acid in transmembrane helix 17 ( TM17 ) was exchanged by the corresponding amino acid of SUR2 . By analyzing cell detachment , nuclear condensation , DNA fragmentation , and caspase-3-like activity , we observed a Q09428 -specific enhancement of glibenclamide-induced apoptosis that was not seen in SUR2B , Q09428 (M1289T) , or control cells . Coexpression with the pore-forming Kir6.2 subunit did not significantly alter the apoptotic effect of glibenclamide on Q09428 cells . In conclusion , expression of Q09428 , but not of SUR2B or Q09428 (M1289T) , renders cells more susceptible to glibenclamide-induced apoptosis . Therefore , Q09428 as a pancreatic protein could be involved in specific variation of beta-cell mass and might also contribute to the regulation of insulin secretion at this level . According to our results , TM17 is essentially involved in Q09428 -mediated apoptosis . This effect does not require the presence of functional Kir6.2-containing K( DB00171 ) channels , which points to additional , so far unknown functions of Q09428 . Behavioral suppression induced by cannabinoids is due to activation of the arachidonic acid cascade in rats . DB00470 ( THC ) is the principle psychoactive ingredient of marijuana and produces various psychoactive effects through the brain cannabinoid ( P21554 ) receptor . The P21554 receptor belongs to the seven-transmembrane domain family of G-protein-coupled receptors and is involved in the arachidonic acid cascade in the brain . Few reports have attempted to clarify the functional role of endogenous cannabinoid and the arachidonic acid cascade through the P21554 receptor using a behavioral paradigm . Therefore , in this study , we clarified the mechanism of cannabinoid-induced suppression of lever pressing in rats , focusing on the arachidonic acid cascade as a novel second messenger of P21554 receptor . Delta(8)-THC and the potent synthetic P21554 receptor agonist HU-210 dose-dependently inhibited lever-pressing performance . The Delta(8)-THC-induced suppression was significantly antagonized by the cyclooxygenase ( P36551 ) inhibitors diclofenac ( 32 mg/kg , i.p. ) , aspirin ( 10 mg/kg , i.p. ) and indomethacin ( 10 mg/kg , i.p. ) . The suppressive effect of HU-210 was also significantly antagonized by 32 mg/kg diclofenac . Prostaglandin E(2) ( 3.2 microg/rat , i.c.v. ) , the final product of the arachidonic acid cascade , significantly inhibited lever pressing similar to Delta(8)-THC and HU-210 . In conclusion , we found that suppression of lever-pressing behavior induced by cannabinoids was mediated through activation of the arachidonic acid cascade via the P21554 receptor . Therefore , it is possible that the psychoactive effects of cannabinoid are due to an increase in the formation of PGE(2) in the brain . The stimulation of ketogenesis by cannabinoids in cultured astrocytes defines carnitine palmitoyltransferase I as a new ceramide-activated enzyme . The effects of cannabinoids on ketogenesis in primary cultures of rat astrocytes were studied . Delta9- DB00470 ( THC ) , the major active component of marijuana , produced a malonyl- DB01992 -independent stimulation of carnitine palmitoyltransferase I ( CPT-I ) and ketogenesis from [14C]palmitate . The THC-induced stimulation of ketogenesis was mimicked by the synthetic cannabinoid HU-210 and was prevented by pertussis toxin and the P21554 cannabinoid receptor antagonist SR141716 . Experiments performed with different cellular modulators indicated that the THC-induced stimulation of ketogenesis was independent of cyclic AMP , Ca2+ , protein kinase C , and mitogen-activated protein kinase ( MAPK ) . The possible involvement of ceramide in the activation of ketogenesis by cannabinoids was subsequently studied . THC produced a P21554 receptor-dependent stimulation of sphingomyelin breakdown that was concomitant to an elevation of intracellular ceramide levels . Addition of exogenous sphingomyelinase to the astrocyte culture medium led to a MAPK-independent activation of ketogenesis that was quantitatively similar and not additive to that exerted by THC . Furthermore , ceramide activated CPT-I in astrocyte mitochondria . Results thus indicate that cannabinoids stimulate ketogenesis in astrocytes by a mechanism that may rely on P21554 receptor activation , sphingomyelin hydrolysis , and ceramide-mediated activation of CPT-I . Proliferation of chicken neuroretina cells induced by v-src , in vitro , depends on activation of the E2F transcription factor . Quiescent chicken or quail retina neuroblasts ( NR ) can be induced to proliferate actively , in culture , by the v-src oncoprotein . The chE2F-1 transcription factor , a physiological partner of the retinoblastoma gene product , is highly expressed in vivo , in dividing chicken neuroretina cells ( P21554 ) . It is sharply down-regulated as cells enter the post-mitotic differentiation stage , thus suggesting that E2F activity is a prerequisite for NR cell proliferation . In the present paper , transient expression assays of different forms of chE2F-1 were used to investigate the function of E2F for switching P21554 cells from a quiescent to a proliferative state in vitro . Attempts to substitute the effects of v-src by an ectopic expression of Q01094 were unsuccessful . However , in the same conditions , Q01094 supports full growth of CEF in serum-depleted medium . Deletion mutants of Q01094 , with potential dominant-negative properties , were transfected in RSV infected P21554 cells . One of these truncated mutants induces a P55008 phase block in RSV-transformed P21554 cells indicating that , although Q01094 overexpression can not overcome the cell proliferation block of post-mitotic P21554 cells Q01094 , activity is an important component of the growth signal pathway delivered by v-src in these nervous cells . Pharmacogenetics of antipsychotic-induced weight gain : review and clinical implications . Second-generation antipsychotics ( SGAs ) , such as risperidone , clozapine and olanzapine , are the most common drug treatments for schizophrenia . SGAs presented an advantage over first-generation antipsychotics ( FGAs ) , particularly regarding avoidance of extrapyramidal symptoms . However , most SGAs , and to a lesser degree FGAs , are linked to substantial weight gain . This substantial weight gain is a leading factor in patient non-compliance and poses significant risk of diabetes , lipid abnormalities ( that is , metabolic syndrome ) and cardiovascular events including sudden death . The purpose of this article is to review the advances made in the field of pharmacogenetics of antipsychotic-induced weight gain ( AIWG ) . We included all published association studies in AIWG from December 2006 to date using the Medline and ISI web of knowledge databases . There has been considerable progress reaffirming previous findings and discovery of novel genetic factors . The P28335 and leptin genes are among the most promising , and new evidence suggests that the P14416 , P01375 , P60880 and P32245 genes are also prominent risk factors . Further promising findings have been reported in novel susceptibility genes , such as P21554 , P08183 , ADRA1A and Q9Y5U4 . More research is required before genetically informed , personalized medicine can be applied to antipsychotic treatment ; nevertheless , inroads have been made towards assessing genetic liability and plausible clinical application . Differential effects of interleukin-2 and interleukin-15 versus interleukin-21 on P01730 + cutaneous T-cell lymphoma cells . In this study , we compared the effects of interleukin-2 ( P60568 ) , P40933 , and Q9HBE4 on gene expression , activation of cell signaling pathways , and functional properties of cells derived from P01730 + cutaneous T-cell lymphoma ( CTCL ) . Whereas both P60568 and P40933 modulated , in a CTCL cell line , the expression of > 1,000 gene transcripts by at least 2-fold , Q9HBE4 up-regulated < 40 genes . All three cytokines induced tyrosine phosphorylation of Jak1 and Jak3 in CTCL cell lines and native leukemic ( Sezary ) cells . However , only P60568 and P40933 strongly activated signal transducers and activators of transcription 5 , phosphoinositide 3-kinase/Akt , and mitogen-activated protein/extracellular signal-regulated kinase ( P29323 ) kinase/ P29323 signaling pathways in the cell lines and mitogen-primed native cells . In contrast , Q9HBE4 selectively activated signal transducers and activators of transcription 3 . Whereas all three cytokines protected CTCL cells from apoptosis , only P60568 and P40933 promoted their proliferation . The effects of the cytokine stimulation were Jak3 kinase- and Jak1 kinase- dependent . These findings document the vastly different effect of P60568 and P40933 versus Q9HBE4 on CTCL cells . They also suggest two novel therapeutic approaches to CTCL and , possibly , other P01730 + T-cell lymphomas : inhibition of the Jak1/Jak3 kinase complex and , given the known strong immunostimulatory properties of Q9HBE4 on CD8+ T , natural killer , and B cells , application of this cytokine to boost an immune response against malignant P01730 + T cells . The cannabinoid DB00470 mediates inhibition of macrophage chemotaxis to RANTES/ P13501 : linkage to the CB2 receptor . The chemotactic response of murine peritoneal macrophages to RANTES/ P13501 was inhibited significantly following pretreatment with DB00470 ( THC ) , the major psychoactive component in marijuana . Significant inhibition of this chemokine directed migratory response was obtained also when the full cannabinoid agonist CP55940 was used . The CB2 receptor-selective ligand O-2137 exerted a robust inhibition of chemotaxis while the P21554 receptor-selective ligand ACEA had a minimal effect . The THC-mediated inhibition was reversed by the CB2 receptor-specific antagonist SR144528 but not by the P21554 receptor-specific antagonist SR141716A . In addition , THC treatment had a minimal effect on the chemotactic response of peritoneal macrophages from CB2 knockout mice . Collectively , these results suggest that cannabinoids act through the CB2 receptor to transdeactivate migratory responsiveness to RANTES/ P13501 . Furthermore , the results suggest that the CB2 receptor may be a constituent element of a network of G protein-coupled receptor signal transductional systems , inclusive of chemokine receptors , that act coordinately to modulate macrophage migration . Inhibition of endocannabinoid neuronal uptake and hydrolysis as strategies for developing anxiolytic drugs . The endocannabinoid system comprises the P21554 and CB2 receptors ( the targets of the Cannabis sativa compound DB00470 ) , the endogenous ligands ( endocannabinoids ) arachidonoyl ethanolamide ( anandamide ) and 2-arachidonoyl glycerol , their synthesizing machinery and membrane transport system , and the hydrolyzing enzymes fatty acid amide hydrolase ( FAAH ) and monoacylglycerol lipase ( Q99685 ) , respectively . The endocannabinoids may act on demand to confer protection against aversive stimuli , which suggests that increasing their brain levels may represent an approach for treatment of anxiety-related disorders . Thus , this article reviews the profile of endocannabinoid reuptake and hydrolysis inhibitors in experimental tests predictive of anxiolytic activity . The FAAH inhibitors and the blockers of anandamide transport , in contrast to direct P21554 receptor agonists , induce anxiolytic effects at doses that do not interfere with motor activity . Q99685 inhibitors also reduce anxiety-like behavior , although they are more likely to impair motor activity . Regarding their mechanisms , increasing anandamide levels induce responses mediated by the P21554 receptor and occluded by the transient receptor potential vanilloid type-1 channels , whereas the effects of increasing 2-arachidonoyl glycerol depend on both P21554 and CB2 receptors . Their neuroanatomical targets include various structures related to anxiety and fear responses . Understanding the pharmacological properties of FAAH and Q99685 inhibitors may contribute toward the development of new anxiolytic interventions based on the endocannabinoid system . Self-administration of cannabinoids by experimental animals and human marijuana smokers . Drug self-administration behavior has been one of the most direct and productive approaches for studying the reinforcing effects of psychoactive drugs , which are critical in determining their abuse potential . Cannabinoids , which are usually abused by humans in the form of marijuana , have become the most frequently abused illicit class of drugs in the United States . The early elucidation of the structure and stereochemistry of DB00470 ( THC ) in 1964 , which is now recognized as the principal psychoactive ingredient in marijuana , activated cannabinoid research worldwide . This review examines advances in research on cannabinoid self-administration behavior by humans and laboratory animals . There have been numerous laboratory demonstrations of the reinforcing effects of cannabinoids in human subjects , but reliable self-administration of cannabinoids by laboratory animals has only recently been demonstrated . It has now been shown that strong and persistent self-administration behavior can be maintained in experimentally and drug-naïve squirrel monkeys by doses of THC comparable to those in marijuana smoke inhaled by humans . Furthermore , reinforcing effects of some synthetic P21554 cannabinoid agonists have been recently reported using intravenous and intracerebroventricular self-administration procedures in rats and mice . These findings support previous conclusions that THC has a pronounced abuse liability comparable to other drugs of abuse under certain experimental conditions . Self-administration of THC by squirrel monkeys provides the most reliable animal model for human marijuana abuse available to date . This animal model now makes it possible to study the relative abuse liability of other natural and synthetic cannabinoids and to preclinically assess new therapeutic strategies for the treatment or prevention of marijuana abuse in humans . Evidence for an interaction between P21554 cannabinoid and melanocortin P08235 -4 receptors in regulating food intake . P32245 ( MCR4 ) and CB(1) cannabinoid receptors independently modulate food intake . Although an interaction between the cannabinoid and melanocortin systems has been found in recovery from hemorrhagic shock , the interaction between these systems in modulating food intake has not yet been examined . The present study had two primary purposes : 1 ) to examine whether the cannabinoid and melanocortin systems act independently or synergistically in suppressing food intake ; and 2 ) to determine the relative position of the CB(1) receptors in the chain of control of food intake in relation to the melanocortin system . Rats were habituated to the test environment and injection procedure and then received intracerebroventicular injections of various combinations of the MCR4 receptor antagonist JKC-363 , the CB(1) receptor agonist Delta(9)-tetrahydrocannabinol , the MCR4 receptor agonist alpha-MSH , or the cannabinoid CB(1) receptor antagonist SR 141716 . Food intake and locomotor activity were then recorded for 120 min . When administrated alone , SR 141716 and alpha-MSH dose-dependently attenuated baseline feeding , whereas sub-anorectic doses of SR 141716 and alpha-MSH synergistically attenuated baseline feeding when combined . Delta(9)- DB00470 -induced feeding was not blocked by alpha-MSH , whereas SR 141716 dose-dependently attenuated JKC-363-induced feeding . Locomotor activity was not significantly affected by any drug treatment , suggesting that the observed effects on feeding were not due to a nonspecific reduction in motivated behavior . These findings revealed a synergistic interaction between the cannabinoid and melanocortin systems in feeding behavior . These results further suggested that CB(1) receptors are located downstream from melanocortin receptors and CB(1) receptor signaling is necessary to prevent the melanocortin system from altering food intake . Anti-inflammatory activity of topical THC in DNFB-mediated mouse allergic contact dermatitis independent of P21554 and CB2 receptors . BACKGROUND : ∆(9) - DB00470 ( THC ) , the active constituent of Cannabis sativa , exerts its biological effects in part through the G-protein-coupled P21554 and CB2 receptors , which were initially discovered in brain and spleen tissue , respectively . However , THC also has P21554 /2 receptor-independent effects . Because of its immune-inhibitory potential , THC and related cannabinoids are being considered for the treatment of inflammatory skin diseases . Here we investigated the mechanism of the anti-inflammatory activity of THC and the role of P21554 and CB2 receptors . METHODS : We evaluated the impact of topically applied THC on DNFB-mediated allergic contact dermatitis in wild-type and P21554 /2 receptor-deficient mice . We performed immunohistochemical analyses for infiltrating immune cells and studied the influence of THC on the interaction between T cells , keratinocytes and myeloid immune cells in vitro . RESULTS : Topical THC application effectively decreased contact allergic ear swelling and myeloid immune cell infiltration not only in wild-type but also in P21554 /2 receptor-deficient mice . We found that THC ( 1 ) inhibited the production of IFNγ by T cells , ( 2 ) decreased the production of P13500 and of IFNγ-induced P80075 and CXL10 by epidermal keratinocytes and ( 3 ) thereby limited the recruitment of myeloid immune cells in vitro in a P21554 /2 receptor-independent manner . CONCLUSIONS : Topically applied THC can effectively attenuate contact allergic inflammation by decreasing keratinocyte-derived pro-inflammatory mediators that orchestrate myeloid immune cell infiltration independent of P21554 /2 receptors . This has important implications for the future development of strategies to harness cannabinoids for the treatment of inflammatory skin diseases . Differential effects of delta9-tetrahydrocannabinol and methanandamide in P21554 knockout and wild-type mice . Mice devoid of P21554 cannabinoid receptors ( P21554 -/- mice ) provide a unique opportunity to further investigate the role of P21554 receptors in exocannabinoid and endocannabinoid effects . P21554 -/- mice ( N = 18 ) and their wild-type littermates ( P21554 +/+ mice ; N = 12 ) were placed in standard mouse operant chambers and trained to lever press under a fixed ratio 10 schedule of reinforcement . When stable lever press responding under the fixed ratio 10 schedule had been established , cannabinoids and noncannabinoids were administered to both groups . P21554 +/+ mice acquired the lever press response more readily than P21554 -/- mice . Delta(9)- DB00470 ( Delta(9)-THC ) decreased lever press responding in P21554 +/+ mice only , whereas methanandamide , a metabolically stable endocannabinoid analog , produced similar response rate decreases in both genotypic groups . Similar to Delta(9)-THC , another endocannabinoid analog , ( R ) - ( 20-cyano-16,16-dimethyl docosa-cis-5,8,11,14-tetraeno ) -1'-hydroxy-2'-propylamine ( O-1812 ) , decreased responding in P21554 +/+ mice , but not in P21554 -/- mice . The P21554 receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1- ( 2,4-dichlorophenyl-4-methyl-1H-pyrazole-3-carboxamide hydrochloride ( SR141716A ) blocked the effects of Delta(9)-THC , but not those of methanandamide . Because methanandamide binds poorly to CB2 receptors , these results suggest possible non- P21554 , non-CB2 mechanisms of action for methanandamide-induced behavioral disruption of lever press responding . DB00898 and morphine elicited greater response decreases in P21554 -/- mice than in P21554 +/+ mice , suggesting a possible role of P21554 receptors in the rate disruptive effects of these drugs . In contrast , diazepam did not produce between group differences , suggesting that P21554 receptors are not involved in diazepam-induced disruption of lever press responding . Increased mortality , hypoactivity , and hypoalgesia in cannabinoid P21554 receptor knockout mice . Delta9- DB00470 ( Delta9-THC ) , the major psychoactive ingredient in preparations of Cannabis sativa ( marijuana , hashish ) , elicits central nervous system ( CNS ) responses , including cognitive alterations and euphoria . These responses account for the abuse potential of cannabis , while other effects such as analgesia suggest potential medicinal applications . To study the role of the major known target of cannabinoids in the CNS , the P21554 cannabinoid receptor , we have produced a mouse strain with a disrupted P21554 gene . P21554 knockout mice appeared healthy and fertile , but they had a significantly increased mortality rate . They also displayed reduced locomotor activity , increased ring catalepsy , and hypoalgesia in hotplate and formalin tests . Delta9-THC-induced ring-catalepsy , hypomobility , and hypothermia were completely absent in P21554 mutant mice . In contrast , we still found Delta9-THC-induced analgesia in the tail-flick test and other behavioral ( licking of the abdomen ) and physiological ( diarrhea ) responses after Delta9-THC administration . Thus , most , but not all , CNS effects of Delta9-THC are mediated by the P21554 receptor . Dopamine agonist-induced hypothermia and disruption of prepulse inhibition : evidence for a role of D3 receptors ? The dopamine D3/D2 receptor agonists 7-OH-DPAT , quinpirole , quinelorane , and PD128907 , the mixed dopamine agonist apomorphine , the D2 agonist bromocriptine , and the D1/D5 agonist SKF38393 were examined in models of hypothermia and prepulse inhibition ( PPI ) in Wistar rats . As dopamine agonist-induced hypothermia has been proposed as a model of D3 receptor function , and dopamine agonists are known to disrupt PPI , drug potencies to induce hypothermia were established and compared with doses necessary to disrupt PPI . 7-OH-DPAT , quinpirole , quinelorane , PD128907 , and apomorphine , reduced body temperature and disrupted PPI with a similar rank order of potency ( quinelorane > quinpirole = 7-OH-DPAT > PD128907 = apomorphine ) . DB01200 and SKF38393 were ineffective in both models . In a separate study , the dopamine reuptake inhibitors cocaine and GBR 12909 had no effect on PPI . In a final set of studies , the D2/D3 antagonist raclopride blocked both 7-OH-DPAT-induced hypothermia and 7-OH-DPAT-induced PPI disruption . The P08908 antagonist WAY 100,135 , and the peripheral D2-like antagonist domperidone had no effect . These findings suggest that the hypothermia and PPI disruptions seen with some of these dopamine agonists may be mediated by central D3 receptors ; however , only studies using more selective dopamine receptor ligands can definitively rule out effects at the D2 or D4 receptors . Some cannabinoid receptor ligands and their distomers are direct-acting openers of Q09428 K( DB00171 ) channels . Here , we examined the chronic effects of two cannabinoid receptor-1 ( P21554 ) inverse agonists , rimonabant and ibipinabant , in hyperinsulinemic Zucker rats to determine their chronic effects on insulinemia . DB06155 and ibipinabant ( 10 mg·kg⁻¹·day⁻¹ ) elicited body weight-independent improvements in insulinemia and glycemia during 10 wk of chronic treatment . To elucidate the mechanism of insulin lowering , acute in vivo and in vitro studies were then performed . Surprisingly , chronic treatment was not required for insulin lowering . In acute in vivo and in vitro studies , the P21554 inverse agonists exhibited acute K channel opener ( KCO ; e.g. , diazoxide and NN414 ) -like effects on glucose tolerance and glucose-stimulated insulin secretion ( GSIS ) with approximately fivefold better potency than diazoxide . Followup studies implied that these effects were inconsistent with a P21554 -mediated mechanism . Thus effects of several P21554 agonists , inverse agonists , and distomers during GTTs or GSIS studies using perifused rat islets were unpredictable from their known P21554 activities . In vivo rimonabant and ibipinabant caused glucose intolerance in P21554 but not Q09428 -KO mice . Electrophysiological studies indicated that , compared with diazoxide , 3 μM rimonabant and ibipinabant are partial agonists for K channel opening . Partial agonism was consistent with data from radioligand binding assays designed to detect Q09428 K( DB00171 ) KCOs where rimonabant and ibipinabant allosterically regulated ³H-glibenclamide-specific binding in the presence of MgATP , as did diazoxide and NN414 . Our findings indicate that some P21554 ligands may directly bind and allosterically regulate Kir6.2/ Q09428 K( DB00171 ) channels like other KCOs . This mechanism appears to be compatible with and may contribute to their acute and chronic effects on GSIS and insulinemia . Arsenic decreases antinociceptive activity of paracetamol : possible involvement of serotonergic and endocannabinoid receptors . We assessed whether repeated arsenic exposure can decrease paracetamol-mediated antinociception by modulating serotonergic and endocannabinoid pathways . Rats were preexposed to elemental arsenic ( 4ppm ) as sodium arsenite through drinking water for 28 days . Next day paracetamol 's ( 400mg/kg , oral ) antinociceptive activity was assessed through formalin-induced nociception . Serotonin content and gene expression of P08908 , 5- Q13049 and P21554 receptors were evaluated in brainstem and frontal cortex . Arsenic decreased paracetamol-mediated analgesia . DB00316 , but not arsenic , increased serotonin content in these regions . Arsenic attenuated paracetamol-mediated increase in serotonin level . DB00316 did not alter P08908 expression , but caused down-regulation of 5- Q13049 and up-regulation of P21554 receptors . Arsenic down-regulated these receptors . However , paracetamol-mediated down-regulation of 5- Q13049 was more pronounced . Arsenic did not modify paracetamol 's effect on P08908 expression , but reduced paracetamol-mediated down-regulation of 5- Q13049 and reversed up-regulation of P21554 receptors . Results suggest arsenic reduced paracetamol-induced analgesia possibly by interfering with pronociceptive 5- Q13049 and antinociceptive P21554 receptors . Expression of P20839 and P12268 after transplantation and initiation of immunosuppression . BACKGROUND : DB01024 ( DB00603 ) mediates immunosuppressive effects by inhibiting inosine monophosphate dehydrogenase ( IMPDH ) . Induction of IMPDH activity has been observed in whole blood and erythrocyte samples during immunosuppressive therapy . Information concerning the mechanisms for increased IMPDH activity is limited and the potential implications of induction have been debated . METHODS : Whole blood , P01730 + cell , and reticulocyte samples were collected from 30 renal transplant patients pre- and posttransplantation . The expressions of two IMPDH isoforms , type 1 and 2 , were analyzed by real-time reverse-transcription polymerase chain reaction and quantified using a housekeeping gene index . The IMPDH activity was determined by ultraviolet high-performance liquid chromatography . RESULTS : Transplantation and the initiation of immunosuppressive therapy was associated with increased P20839 ( 50-88 % , P < 0.0005 ) and decreased P12268 ( 42-56 % , P < 0.0005 ) expression . In P01730 + cells , however , P12268 increased ( 15 % , P=0.009 ) . These changes are probably related to glucocorticoid effects . Two weeks posttransplant , DB00603 -treated patients displayed elevated P20839 and 2 in reticulocytes , suggesting enzyme induction in these cells during prolonged DB00603 therapy . Patients with acute rejection during follow-up demonstrated higher P12268 expression in P01730 + cells pretransplant than nonrejecting patients ( median expression 1.26 vs. 0.87 respectively , P=0.017 ) . CONCLUSIONS : Knowledge of changes in P20839 and 2 expression after transplantation and initiation of immunosuppression is important considering the action of DB00603 on IMPDH and the potential for pharmacodynamic monitoring of DB00603 by measuring IMPDH activity . The expression of P12268 in P01730 + cells pretransplant may be an indicator of immune activation . Cannabinoid receptors and their endogenous ligands . Delta9- DB00470 , a major psychoactive component of marijuana , has been shown to interact with specific cannabinoid receptors , thereby eliciting a variety of pharmacological responses in experimental animals and human . In 1990 , the gene encoding a cannabinoid receptor ( P21554 ) was cloned . This prompted the search for endogenous ligands . In 1992 , N-arachidonoylethanolamine ( anandamide ) was isolated from pig brain as an endogenous ligand , and in 1995 , 2-arachidonoylglycerol was isolated from rat brain and canine gut as another endogenous ligand . Both anandamide and 2-arachidonoylglycerol exhibit various cannabimimetic activities . The results of structure-activity relationship experiments , however , revealed that 2-arachidonoylglycerol , but not anandamide , is the intrinsic natural ligand for the cannabinoid receptor . 2-Arachidonoylglycerol is a degradation product of inositol phospholipids that links the function of cannabinoid receptors with the enhanced inositol phospholipid turnover in stimulated tissues and cells . The possible physiological roles of cannabinoid receptors and 2-arachidonoylglycerol in various mammalian tissues such as those of the nervous system are discussed . [ Neuropsychopharmacology of DB00470 ] . Today , the main route of introduction of tetrahydrocannabinol ( THC ) , the main active substance of cannabis , into the human body is via the lungs , from smokes produced by combustion of a haschich-tobacco mixture . The use of a water pipe ( nargileh-like ) intensifies its fast supply to the body . THC reaches the brain easily where it stimulates P21554 receptors ; their ubiquity underlies a wide variety of effects . THC disappears from extracellular spaces by dissolving in lipid rich membranes , and not by excretion from the body . This is followed by a slow release , leading to long lasting effects originating from brain areas containing a large proportion of spare receptors ( " reserve receptors " ) . Far from mimicking the effects of endocannabinoids , THC caricatures and disturbs them . It induces both psychical and physical dependencies , but the perception of withdrawal is weak on account of its very slow elimination . THC disturbs cognition . Acutely , it develops anxiolytic- and antidepressant-like effects , which causes a lot of users to abuse THC , thus leading to a tolerance ( desensitization of P21554 receptors ) making anxiety and depression to reappear more intensely than originally . THC has close relationships with schizophrenia . It incites to tobacco , alcohol and heroine abuses . Potential antipsychotic properties of central cannabinoid ( P21554 ) receptor antagonists . Delta(9)- DB00470 ( Delta(9)-THC ) , the principal psychoactive constituent of the Cannabis sativa plant , and other agonists at the central cannabinoid ( CB(1) ) receptor may induce characteristic psychomotor effects , psychotic reactions and cognitive impairment resembling schizophrenia . These effects of Delta(9)-THC can be reduced in animal and human models of psychopathology by two exogenous cannabinoids , cannabidiol ( DB09061 ) and SR141716 . DB09061 is the second most abundant constituent of Cannabis sativa that has weak partial antagonistic properties at the CB(1) receptor . DB09061 inhibits the reuptake and hydrolysis of anandamide , the most important endogenous CB(1) receptor agonist , and exhibits neuroprotective antioxidant activity . SR141716 is a potent and selective CB(1) receptor antagonist . Since both DB09061 and SR141716 can reverse many of the biochemical , physiological and behavioural effects of CB(1) receptor agonists , it has been proposed that both DB09061 and SR141716 have antipsychotic properties . Various experimental studies in animals , healthy human volunteers , and schizophrenic patients support this notion . Moreover , recent studies suggest that cannabinoids such as DB09061 and SR141716 have a pharmacological profile similar to that of atypical antipsychotic drugs . In this review , both preclinical and clinical studies investigating the potential antipsychotic effects of both DB09061 and SR141716 are presented together with the possible underlying mechanisms of action . Cannabinoid agonists in the treatment of blepharospasm -- a case report study . The benign essential blepharospasm is a subliminal form of primary torsion dystonia with still uncertain aetiology . It is characterized by involuntary convulsive muscle contractions of the M. orbicularis occuli , accompanied by unbearable pain of the cornea , eye bulb and the muscle itself . It has been suggested that blepharospasm is neurobiologically based on a dysfunction of the basal ganglia and an impairment of the dopamine neurotransmitter system . Therefore , therapy of blepharospasm contains administration of anticholinergic- and tranquillizing drugs as well as botulinum toxin as neuromuscular blocking agent . However serious side effects can be observed as well as failure of therapy . In the brain a dense co-localisation of cannabinoid ( P21554 ) and dopamine ( D2 ) -receptor was identified which had been associated with the influence of cannabinoids on the dopaminergic reward system . Additionally , it has been demonstrated that cannabinoids may have an impact on the central GABAergic and glutaminergic transmitter system and thus might be involved in the influence of movement control . In the present case we administered the cannabinoid receptor agonist Dronabinol ( Delta-9- DB00470 ) to a woman suffering from severe blepharospasm . Multiple treatments with botulinum toxin did not reveal a long-lasting beneficial effect . By contrast , treatment with 25 mg Dronabinol for several weeks improved the patients ' social life and attenuated pain perception remarkably . This case study demonstrates that the therapy with a cannabinoid agonist may provide a novel tool in the treatment of blepharospasm and maybe of other multifactorial related movement disorders . The maintenance of cisplatin- and paclitaxel-induced mechanical and cold allodynia is suppressed by cannabinoid CB₂ receptor activation and independent of P61073 signaling in models of chemotherapy-induced peripheral neuropathy . BACKGROUND : Chemotherapeutic agents produce dose-limiting peripheral neuropathy through mechanisms that remain poorly understood . We previously showed that AM1710 , a cannabilactone CB₂ agonist , produces antinociception without producing central nervous system ( CNS ) -associated side effects . The present study was conducted to examine the antinociceptive effect of AM1710 in rodent models of neuropathic pain evoked by diverse chemotherapeutic agents ( cisplatin and paclitaxel ) . A secondary objective was to investigate the potential contribution of alpha-chemokine receptor ( P61073 ) signaling to both chemotherapy-induced neuropathy and CB₂ agonist efficacy . RESULTS : AM1710 ( 0.1 , 1 or 5 mg/kg i.p. ) suppressed the maintenance of mechanical and cold allodynia in the cisplatin and paclitaxel models . Anti-allodynic effects of AM1710 were blocked by the CB₂ antagonist AM630 ( 3 mg/kg i.p. ) , but not the P21554 antagonist AM251 ( 3 mg/kg i.p. ) , consistent with a CB₂-mediated effect . By contrast , blockade of P61073 signaling with its receptor antagonist DB06809 ( 10 mg/kg i.p. ) failed to attenuate mechanical or cold hypersensitivity induced by either cisplatin or paclitaxel . Moreover , blockade of P61073 signaling failed to alter the anti-allodynic effects of AM1710 in the paclitaxel model , further suggesting distinct mechanisms of action . CONCLUSIONS : Our results indicate that activation of cannabinoid CB₂ receptors by AM1710 suppresses both mechanical and cold allodynia in two distinct models of chemotherapy-induced neuropathic pain . By contrast , P61073 signaling does not contribute to the maintenance of chemotherapy-induced established neuropathy or efficacy of AM1710 . Our studies suggest that CB₂ receptors represent a promising therapeutic target for the treatment of toxic neuropathies produced by cisplatin and paclitaxel chemotherapeutic agents . The effectiveness of lurasidone as an adjunct to lithium or divalproex in the treatment of bipolar disorder . The majority of patients with bipolar disorder spend a lot of time in depressive episodes that impose a great burden on patients , caregivers , and society and accounts for the largest part of the morbidity-mortality of the illness . DB08815 is an atypical antipsychotic with a potent binding affinity as antagonist for D2 , 5- Q13049 , P34969 , and partial agonist at P08908 receptors . Affinity for other receptors as H1 and muscarinic were negligible . DB08815 was approved in 2010 for the treatment of schizophrenia and recently , 2013 , for bipolar depression in monotherapy and an adjunct to lithium or valproate . Clinical trials have established that lurasidone adjuvant to lithium or valproate has more efficacy than the placebo and is associated with minimal weight gain and no clinically meaningful alterations in glucose , lipids , or the QT interval . Additional studies are desirable to know the clinical profile of lurasidone in long-term treatment , in patients with bipolar II disorders , and versus other antipsychotic agents . Molecular basis of the structural stability of a Top7-based scaffold at extreme pH and temperature conditions . The development of stable biomolecular scaffolds that can tolerate environmental extremes has considerable potential for industrial and defense-related applications . However , most natural proteins are not sufficiently stable to withstand non-physiological conditions . We have recently engineered the de novo designed Top7 protein to specifically recognize the glycoprotein P01730 by insertion of an eight-residue loop . The engineered variant exhibited remarkable stability under chemical and thermal denaturation conditions . In the present study , far-UV CD spectroscopy and explicit-solvent MD simulations are used to investigate the structural stability of Top7 and the engineered variant under extreme conditions of temperature and pH . Circular dichroism measurements suggest that the engineered variant Top7( P21554 ) , like Top7 , retains its structure at high temperatures . Changes in CD spectra suggest that there are minor structural rearrangements between neutral and acidic environments for both proteins but that these do not make the proteins less stable at high temperatures . The anti-parallel beta-sheet is well conserved within the timescale simulated whereas there is a decrease of helical content when low pH and high-temperature conditions are combined . Concerted alanine mutations along the alpha-helices of the engineered Top7 variant did not revert this trend when at pH 2 and 400K . The structural resilience of the anti-parallel beta-sheet suggests that the protein scaffold can accommodate varying sequences . The robustness of the Top7 scaffold under extreme conditions of pH and temperature and its amenability to production in inexpensive bacterial expression systems reveal great potential for novel biotechnological applications . Beneficial effects of cannabinoids ( CB ) in a murine model of allergen-induced airway inflammation : role of P21554 /CB2 receptors . The endocannabinoid system ( ECS ) consists of two cannabinoid ( CB ) receptors , namely CB(1) and CB(2) receptor , and their endogenous ( endocannabinoids ) and exogenous ( cannabinoids , e.g. DB00470 ( THC ) ) ligands which bind to these receptors . Based on studies suggesting a role of THC and the ECS in inflammation , the objective of this study was to examine their involvement in type I hypersensitivity using a murine model of allergic airway inflammation . THC treatment of C57BL/6 wildtype mice dramatically reduced airway inflammation as determined by significantly reduced total cell counts in bronchoalveolar lavage ( BAL ) . These effects were greatest when mice were treated during both , the sensitization and the challenge phase . Furthermore , systemic immune responses were significantly suppressed in mice which received THC during sensitization phase . To investigate a role of CB(1/2) receptors in this setting , we used pharmacological blockade of CB(1) and/or CB(2) receptors by the selective antagonists and moreover CB(1)/CB(2) receptor double-knockout mice ( CB(1)(-/-)/CB(2)(-/-) ) and found neither significant changes in the cell patterns in BAL nor in immunoglobulin levels as compared to wildtype mice . Our results indicate that the activation of the ECS by applying the agonist THC is involved in the development of type I allergies . However , CB(1)/CB(2) receptor-independent signalling seems likely in the observed results . CB2 receptors in the brain : role in central immune function . Recently , it has been recognized that the cannabinoid receptor CB2 may play a functionally relevant role in the central nervous system ( CNS ) . This role is mediated primarily through microglia , a resident population of cells in the CNS that is morphologically , phenotypically , and functionally related to macrophages . These cells also express the cannabinoid receptor P21554 . The P21554 receptor ( CB1R ) is constitutively expressed at low levels while the CB2 receptor ( CB2R ) is expressed at higher levels and is modulated in relation to cell activation state . The relatively high levels of the CB2R correspond with microglia being in ' responsive ' and ' primed ' states , suggesting the existence of a ' window ' of functional relevance during which activation of the CB2R modulates microglial activities . Signature activities of ' responsive ' and ' primed ' microglia are chemotaxis and antigen processing , respectively . The endocannabinoid 2-arachidonylglycerol has been reported to stimulate a chemotactic response from these cells through the CB2R . In contrast , we have shown in vivo and in vitro that the exogenous cannabinoids DB00470 and CP55940 inhibit the chemotactic response of microglia to Acanthamoeba culbertsoni , an opportunistic pathogen that is the causative agent of Granulomatous Amoebic Encephalitis , through activation of the CB2R . It is postulated that these exogenous cannabinoids superimpose an inhibitory effect on pro-chemotactic endocannabinoids that are elicited in response to Acanthamoeba . Furthermore , the collective results suggest that the CB2R plays a critical immune functional role in the CNS . Adolescent exposure to chronic DB00470 blocks opiate dependence in maternally deprived rats . Maternal deprivation in rats specifically leads to a vulnerability to opiate dependence . However , the impact of cannabis exposure during adolescence on this opiate vulnerability has not been investigated . Chronic dronabinol ( natural delta-9 tetrahydrocannabinol , THC ) exposure during postnatal days 35-49 was made in maternal deprived ( D ) or non-deprived ( animal facility rearing , AFR ) rats . The effects of dronabinol exposure were studied after 2 weeks of washout on the rewarding effects of morphine measured in the place preference and oral self-administration tests . The preproenkephalin ( PPE ) mRNA levels and the relative density and functionality of P21554 , and mu-opioid receptors were quantified in the striatum and the mesencephalon . Chronic dronabinol exposure in AFR rats induced an increase in sensitivity to morphine conditioning in the place preference paradigm together with a decrease of PPE mRNA levels in the nucleus accumbens and the caudate-putamen nucleus , without any modification for preference to oral morphine consumption . In contrast , dronabinol treatment on D-rats normalized PPE decrease in the striatum , morphine consumption , and suppressed sensitivity to morphine conditioning . P21554 and mu-opioid receptor density and functionality were not changed in the striatum and mesencephalon of all groups of rats . These results indicate THC potency to act as a homeostatic modifier that would worsen the reward effects of morphine on naive animals , but ameliorate the deficits in maternally D-rats . These findings point to the self-medication use of cannabis in subgroups of individuals subjected to adverse postnatal environment . Chronic DB00470 treatment increases DB02527 levels and DB02527 -dependent protein kinase activity in some rat brain regions . When Delta(9)-tetrahydrocannabinol ( Delta(9)-THC,15 mg/kg ) was injected intraperitoneally twice a day for 6 days , tolerance to its analgesic effect appeared to be complete . Chronic exposure to Delta(9)-THC caused a significant reduction in P21554 receptor binding in all brain areas that contain this receptor . Cannabinoid receptor density was markedly reduced in the cerebellum ( 52 % ) , hippocampus ( 40 % ) and globus pallidum ( 47 % ) compared to 30 % in the cortex and striatum . Chronic exposure enhanced the DB02527 pathway , as shown by the significant increase of DB02527 levels and PKA activity in the areas with receptor down-regulation ( cerebellum , striatum and cortex ) . We propose that the increase in DB02527 cascade is part of the biochemical basis of cannabinoid tolerance . Opposing control of cannabinoid receptor stimulation on amyloid-beta-induced reactive gliosis : in vitro and in vivo evidence . Beside cytotoxic mechanisms impacting on neurons , amyloid beta ( A beta ) -induced astroglial activation is operative in Alzheimer 's disease brain , suggesting that persistent inflammatory response may have a role in the illness and that positive results may be achieved by curbing the astroglial reaction . Because the role of the endocannabinoid system could represent a promising field of research , the present study conducted in vitro and in vivo experiments to assess this system . P13671 rat astroglioma cells were challenged with 1 microg/ml A beta 1-42 in the presence or absence of selective agonists and antagonists of cannabinoid (CB)1 and CB2 receptors . Furthermore , rats were inoculated into the frontal cortex with 30 ng of A beta 1-42 and were i.p. administered with 5 mg/kg of the same substances . Immunohistochemical and biochemical findings revealed that selective agonism at P21554 and antagonism at CB2 receptors was able to blunt A beta-induced reactive astrogliosis with subsequent overexpression of glial fibrillary acidic protein and P04271 protein . Moreover , A beta provoked down-regulation of P21554 receptors together with a reduction of anandamide concentration , whereas CB2 receptors were up-regulated and 2-arachidonoyl glycerol concentration was increased . Finally , to our knowledge , the current study is the first showing that interactions at cannabinoid receptors result in a dual regulation of A beta-induced reactive astrogliosis . The data support the assumption that compounds able to selectively block CB2 receptors may have therapeutic potential in controlling A beta-related pathology , due to their beneficial effects devoid of psychotropic consequences . The endogenous cannabinoid anandamide produces DB00470 -like discriminative and neurochemical effects that are enhanced by inhibition of fatty acid amide hydrolase but not by inhibition of anandamide transport . Anandamide is an endogenous ligand for brain cannabinoid CB(1) receptors , but its behavioral effects are difficult to measure due to rapid inactivation . Here we used a drug-discrimination procedure to test the hypothesis that anandamide , given i.v. or i.p. , would produce discriminative effects like those of DB00470 ( THC ) in rats when its metabolic inactivation was inhibited . We also used an in vivo microdialysis procedure to investigate the effects of anandamide , given i.v. or i.p. , on dopamine levels in the nucleus accumbens shell in rats . When injected i.v. , methanandamide ( AM-356 ) , a metabolically stable anandamide analog , produced clear dose-related THC-like discriminative effects , but anandamide produced THC-like discriminative effects only at a high 10-mg/kg dose that almost eliminated lever-press responding . Cyclohexyl carbamic acid 3'-carbamoyl-biphenyl-3-yl ester ( Q76M96 -597 ) , an inhibitor of fatty acid amide hydrolase ( FAAH ) , the main enzyme responsible for metabolic inactivation of anandamide , produced no THC-like discriminative effects alone but dramatically potentiated discriminative effects of anandamide , with 3 mg/kg anandamide completely substituting for the THC training dose . Q76M96 -597 also potentiated the ability of anandamide to increase dopamine levels in the accumbens shell . The THC-like discriminative-stimulus effects of anandamide after Q76M96 -597 and methanandamide were blocked by the P21554 receptor antagonist rimonabant , but not the vanilloid Q8NER1 receptor antagonist capsazepine . Surprisingly , the anandamide transport inhibitors N-(4-hydroxyphenyl)-eicosa-5,8,11,14-tetraenamide ( AM-404 ) and N-(3-furylmethyl)eicosa-5,8,11,14-tetraenamide ( UCM-707 ) did not potentiate THC-like discriminative effects of anandamide or its dopamine-elevating effects . Thus , anandamide has THC-like discriminative and neurochemical effects that are enhanced after treatment with a FAAH inhibitor but not after treatment with transport inhibitors , suggesting brain area specificity for FAAH versus transport/FAAH inactivation of anandamide . Reinforcing and neurochemical effects of cannabinoid P21554 receptor agonists , but not cocaine , are altered by an adenosine A2A receptor antagonist . Several recent studies suggest functional and molecular interactions between striatal adenosine A(2A) and cannabinoid CB(1) receptors . Here , we demonstrate that A(2A) receptors selectively modulate reinforcing effects of cannabinoids . We studied effects of A(2A) receptor blockade on the reinforcing effects of DB00470 ( THC ) and the endogenous CB(1) receptor ligand anandamide under a fixed-ratio schedule of intravenous drug injection in squirrel monkeys . A low dose of the selective adenosine A(2A) receptor antagonist MSX-3 ( 1 mg/kg ) caused downward shifts of THC and anandamide dose-response curves . In contrast , a higher dose of MSX-3 ( 3 mg/kg ) shifted THC and anandamide dose-response curves to the left . MSX-3 did not modify cocaine or food pellet self-administration . Also , MSX-3 neither promoted reinstatement of extinguished drug-seeking behavior nor altered reinstatement of drug-seeking behavior by non-contingent priming injections of THC . Finally , using in vivo microdialysis in freely-moving rats , a behaviorally active dose of MSX-3 significantly counteracted THC-induced , but not cocaine-induced , increases in extracellular dopamine levels in the nucleus accumbens shell . The significant and selective results obtained with the lower dose of MSX-3 suggest that adenosine A(2A) antagonists acting preferentially at presynaptic A(2A) receptors might selectively reduce reinforcing effects of cannabinoids that lead to their abuse . However , the appearance of potentiating rather than suppressing effects on cannabinoid reinforcement at the higher dose of MSX-3 would likely preclude the use of such a compound as a medication for cannabis abuse . DB00640 A(2A) antagonists with more selectivity for presynaptic versus postsynaptic receptors could be potential medications for treatment of cannabis abuse . Activation of gonadotropin-releasing hormone receptors induces a long-term enhancement of excitatory postsynaptic currents mediated by ionotropic glutamate receptors in the rat hippocampus . Whole-cell patch-clamp recordings were made from P00915 pyramidal neurons of the rat hippocampus to study the modulation of gonadotropin-releasing hormone ( DB00644 ) on synaptic transmission mediated by ionotropic glutamate receptors . DB00007 ( 10(-9)-10(-7) M ) , a specific DB00644 analog , concentration-dependently elicited a long-lasting potentiation of excitatory postsynaptic currents ( EPSCs ) mediated by ionotropic glutamate receptors . P30968 -induced synaptic potentiation was blocked by 1 microM [ Acetyl-3,4-dehydro-Pro1,D-p-F-Phe2,D-Trp3,6 ] - P01148 , a specific P30968 antagonist . Furthermore , P30968 -induced synaptic potentiation was associated with the stimulation of protein kinase C ( PKC ) , being considerably attenuated by a potent PKC inhibitor ( 30 microM H-7 ) . The results suggest a long-term enhanced modulation of DB00644 on synaptic transmission mediated by ionotropic glutamate receptors , possibly via the actions of PKC in the hippocampus that is an important integrative system in the regulation of reproductive processes . DB00472 induces preventive and complex effects against colon cancer development in epithelial and stromal areas in rats . DB00472 ( FLX ) is a drug commonly used as antidepressant . However , its effects on tumorigenesis remain controversial . Aiming to evaluate the effects of FLX treatment on early malignant changes , we analyzed serotonin ( 5-HT ) metabolism and recognition , aberrant crypt foci ( Q9NQ94 ) , proliferative process , microvessels , vascular endothelial growth factor ( P15692 ) , and cyclooxygenase-2 ( P35354 ) expression in colon tissue . Male Wistar rats received a daily FLX-gavage ( 30mgkg(-1) ) and , a single dose of 1,2 dimethylhydrazine ( Q03001 ; i.p. , 125mgkg(-1) ) . After 6 weeks of FLX-treatment , our results revealed that FLX and nor-fluoxetine ( N-FLX ) are present in colon tissue , which was related to significant increase in serotonin ( 5-HT ) levels ( P < 0.05 ) possibly through a blockade in P31645 mRNA ( serotonin reuptake transporter ; P < 0.05 ) resulting in lower 5-hydroxyindoleacetic acid ( 5-HIAA ) levels ( P < 0.01 ) and , P28335 receptor mRNA expressions . FLX-treatment decreased dysplastic Q9NQ94 development ( P < 0.01 ) and proliferative process ( P < 0.001 ) in epithelia . We observed a significant decrease in the development of malignant microvessels ( P < 0.05 ) , P15692 ( P < 0.001 ) , and P35354 expression ( P < 0.01 ) . These findings suggest that FLX may have oncostatic effects on carcinogenic colon tissue , probably due to its modulatory activity on 5-HT metabolism and/or its ability to reduce colonic malignant events . Opposite function of dopamine D1 and N-methyl-D-aspartate receptors in striatal cannabinoid-mediated signaling . It is well established that the cannabinoid and dopamine systems interact at various levels to regulate basal ganglia function . Although it is well known that acute administration of cannabinoids to mice can modify dopamine-dependent behaviors , the intraneuronal signaling pathways employed by these agents in the striatum are not well understood . Here we used knockout mouse models to examine the regulation of striatal extracellular-signal-regulated kinases 1 and 2 ( P27361 /2 ) signaling by behaviorally relevant doses of cannabinoids . This cellular pathway has been implicated as a central mediator of drug reward and synaptic plasticity . In C57BL/6J mice , acute administration of the cannabinoid agonists , (-)-11-hydroxydimethylheptyl-Δ8-tetrahydrocannabinol ( HU-210 ) and DB00470 ( Δ(9) -THC ) , promoted a dose- and time-dependent decrease in the phosphorylation of P27361 /2 in dorsal striatum . Co-administration of the P21554 cannabinoid receptor antagonist N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide(AM251) with HU-210 prevented P27361 /2 inactivation , indicating a requirement for activation of this receptor . In dopamine D1 receptor knockout animals treated with HU-210 , the magnitude of the HU-210-dependent decrease in striatal P27361 /2 signaling was greater than in wild-type controls . In contrast , HU-210 administration to N-methyl-D-aspartate receptor knockdown mice was ineffective at promoting striatal P27361 /2 inactivation . Genetic deletion of other potential P27361 /2 mediators , the dopamine D2 receptors or β-arrestin-1 or -2 , did not affect the HU-210-induced modulation of P27361 /2 signaling in the striatum . These results support the hypothesis that dopamine D1 receptors and N-methyl-D-aspartate receptors act in an opposite manner to regulate striatal P21554 cannabinoid receptor signal transduction . Construction of a steric map of the binding pocket for cannabinoids at the cannabinoid receptor . In order to gain information about the topology of the brain cannabinoid receptor ( P21554 ) , a Receptor Steric ( RS ) Map for cannabinoids at this receptor was calculated . The classical cannabinoids (-)-11-hydroxy- DB00470 ( P04264 = 210 +/- 56 nM ) , (-)-9-nor-9-beta-hydroxy-hexahydrocannabinol ( P04264 = 124 +/- 17 nM ) , nabilone ( P04264 = 120 +/- 13 nM ) , and the non-classical cannabinoid , CP-55,244 ( P04264 = 1.4 +/- .3 nM ) were used as template molecules . The RS map was obtained as the union of the van der Waals ' volumes of only those accessible conformers identified by P08253 calculations that were able to clear a region of steric interference at the P21554 receptor previously characterized by us [ Reggio , P.H. , Panu , A.M. and Miles , S. ( 1993 ) , J. Med. Chem. , 36 , 1761-1771 ] . The utility of the RS Map was explored by screening the accessible conformers of the classical cannabinoid , cannabinol ( CBN ) , ( P04264 = 3200 +/- 450 nM ) , for its ability to fit within the RS map . Only the global minimum energy conformer of CBN ( 53.2 % abundance at 298K ) was able to fit within the RS map . These results imply that one reason for the reduced affinity of CBN may be that only 53.2 % of CBN molecules are shaped properly to fit in the binding pocket for cannabinoids at the P21554 receptor . Cannabinoid P21554 receptor activation mediates the opposing effects of amphetamine on impulsive action and impulsive choice . It is well known that acute challenges with psychostimulants such as amphetamine affect impulsive behavior . We here studied the pharmacology underlying the effects of amphetamine in two rat models of impulsivity , the 5-choice serial reaction time task ( 5-CSRTT ) and the delayed reward task ( P29323 ) , providing measures of inhibitory control , an aspect of impulsive action , and impulsive choice , respectively . We focused on the role of cannabinoid P21554 receptor activation in amphetamine-induced impulsivity as there is evidence that acute challenges with psychostimulants activate the endogenous cannabinoid system , and P21554 receptor activity modulates impulsivity in both rodents and humans . Results showed that pretreatment with either the P21554 receptor antagonist/inverse agonist SR141716A or the neutral P21554 receptor antagonist O-2050 dose-dependently improved baseline inhibitory control in the 5-CSRTT . Moreover , both compounds similarly attenuated amphetamine-induced inhibitory control deficits , suggesting that P21554 receptor activation by endogenously released cannabinoids mediates this aspect of impulsive action . Direct P21554 receptor activation by Δ9- DB00470 ( Δ9-THC ) did , however , not affect inhibitory control . Although neither SR141716A nor O-2050 affected baseline impulsive choice in the P29323 , both ligands completely prevented amphetamine-induced reductions in impulsive decision making , indicating that P21554 receptor activity may decrease this form of impulsivity . Indeed , acute Δ9-THC was found to reduce impulsive choice in a P21554 receptor-dependent way . Together , these results indicate an important , though complex role for cannabinoid P21554 receptor activity in the regulation of impulsive action and impulsive choice as well as the opposite effects amphetamine has on both forms of impulsive behavior . [ Cannabis use disorder and treatment of dependence ] . Cannabis , known as marijuana , has been used illicit drug by young people in the world . In our country , the number of user for cannabis is recently increased gradually . It has been suggested that regular use of cannabis might induce several adverse effects such as dependence syndrome , because DB00470 (THC) , a primary psychoactive component of cannabis , stimulates brain-reward areas through the activation of cannabinoid( P21554 ) receptor and induce drug-seeking behavior . Therefore , it is necessary to investigate and establish the medications for cannabis dependence . In fact , controlled laboratory studies and small open-label clinical studies have shown that several candidates of medications for cannabinoid dependence are identified . Further investigation in controlled clinical trials may produce the therapeutic benefit for treatment about cannabis-related problems . Synthesis , biological activity and HPLC validation of 1,2,3,4-tetrahydroacridine derivatives as acetylcholinesterase inhibitors . The synthesis and biochemical evaluation of new hybrids of tacrine ( DB00382 ) and 4-fluorobenzoic acid ( 4-FBA ) possessing activity towards acetylcholinesterase ( P22303 ) and butyrylcholinesterase ( BuChE ) inhibition are presented . The compounds of interest were obtained from the reaction of activated 4-FBA and diamino derivatives of 1,2,3,4-tetrahydroacridine . The compounds P13671 -2KW/HCl , P13671 -4KW/HCl and P13671 -3KW/HCl have four-fold higher antiacetylcholinesterase activity than DB00382 . All of the acquired compounds present higher selectivity towards P22303 than DB00382 and lower selectivity towards BuChE . In addition , a rapid , selective and stability-indicating HPLC method was developed and validated for the determination of P13671 -2KW/HCl , P13671 -3KW/HCl and P13671 -4KW/HCl . DB00382 and 4-FBA were found to be the main impurities . Chromatographic separation was achieved isocratically on a Waters Symmetry C18 150 × 3.9 mm , 4 μm column with a mobile phase of acetonitrile/buffer ( 17 mM sodium dodecyl sulphate and 8.3 mM sodium dihydrogen phosphate , 50:50 v/v ) ( overall pH 4 ) . A 1.5 ml/min flow rate and a 247 nm wavelength were chosen for this method . P13671 -2KW/HCl , P13671 -3KW/HCl and P13671 -4KW/HCl were subjected to acidic and basic hydrolysis , chemical oxidation , thermal exposition at 60 °C and intense UV light . The limits of detection ( LOD ) and quantification ( LOQ ) were less than 2 μg/ml and 6 μg/ml for P13671 -2KW/HCl , P13671 -3KW/HCl and P13671 -4KW/HCl , 0.04 μg/ml and 0.12 μg/ml for DB00382 , 0.42 μg/ml and 1.41 μg/ml for 4-FBA , respectively . Cannabinoid physiology and pharmacology : 30 years of progress . Delta9- DB00470 from Cannabis sativa is mimicked by cannabimimetic analogs such as CP55940 and WIN55212-2 , and antagonized by rimonabant and SR144528 , through G-protein-coupled receptors , P21554 in the brain , and CB2 in the immune system . Eicosanoids anandamide and 2-arachidonoylglycerol are the " endocannabinoid " agonists for these receptors . P21554 receptors are abundant in basal ganglia , hippocampus and cerebellum , and their functional activity can be mapped during behaviors using cerebral metabolism as the neuroimaging tool . P21554 receptors couple to G(i/o) to inhibit DB02527 production , decrease Ca2+ conductance , increase K+ conductance , and increase mitogen-activated protein kinase activity . Functional activation of G-proteins can be imaged by [35S]GTPgammaS autoradiography . Post-synaptically generated endocannabinoids form the basis of a retrograde signaling mechanism referred to as depolarization-induced suppression of inhibition ( DSI ) or excitation ( Q9UL01 ) . Under circumstances of sufficient intracellular Ca2+ ( e.g. , burst activity in seizures ) , synthesis of endocannabinoids releases a diffusible retrograde messenger to stimulate presynaptic P21554 receptors . This results in suppression of gamma-aminobutyric acid ( GABA ) release , thereby relieving the post-synaptic inhibition . Tolerance develops as neurons adjust both receptor number and cellular signal transduction to the chronic administration of cannabinoid drugs . Future therapeutic drug design can progress based upon our current understanding of the physiology and pharmacology of P21554 , CB2 and related receptors . One very important role for P21554 antagonists will be in the treatment of craving in the disease of substance abuse . Distribution of cannabinoid receptors in the central and peripheral nervous system . P21554 cannabinoid receptors appear to mediate most , if not all of the psychoactive effects of DB00470 and related compounds . This G protein-coupled receptor has a characteristic distribution in the nervous system : It is particularly enriched in cortex , hippocampus , amygdala , basal ganglia outflow tracts , and cerebellum -- a distribution that corresponds to the most prominent behavioral effects of cannabis . In addition , this distribution helps to predict neurological and psychological maladies for which manipulation of the endocannabinoid system might be beneficial . P21554 receptors are primarily expressed on neurons , where most of the receptors are found on axons and synaptic terminals , emphasizing the important role of this receptor in modulating neurotransmission at specific synapses . While our knowledge of P21554 localization in the nervous system has advanced tremendously over the past 15 years , there is still more to learn . Particularly pressing is the need for ( 1 ) detailed anatomical studies of brain regions important in the therapeutic actions of drugs that modify the endocannabinoid system and ( 2 ) the determination of the localization of the enzymes that synthesize , degrade , and transport the endocannabinoids . [ Characteristics of abnormal behavior induced by delta 9-tetrahydrocannabinol in rats ] . delta 9- DB00470 ( THC ) , one of the active compounds of marihuana , is known to induce drug dependence and tolerance , and its action is weaker than those of other abused drugs in humans and animals . Acute effects of THC , " high " , " irritable " and " cognitive deficits " are more important than the drug dependence and tolerance . For this reason , we examined characteristics of abnormal behavior such as catalepsy-like immobilization , aggressive behavior including irritable aggression and muricide , and spatial cognition impairment induced by acute and chronic treatments of THC in rats . The catalepsy-like immobilization is related to a decrease in catecholaminergic and serotonergic neurons in the nucleus accumbens and amygdaloid nucleus and thus serves as a useful model for amotivational syndrome , one of cannabis psychoses . In aggressive behavior , muricide was determined by the housing condition . Muricide was induced if the rat was placed under an isolated housing condition within the period of the effect of single injection of THC . The behavioral change resembles exacerbation and flashback in humans . Spatial cognition is impaired by the interaction between cannabinoid ( P21554 ) and 5-HT2 receptor in the dorsal raphe-hippocampal serotonergic neurons . Thus the abnormal behavior induced by THC can be a useful model for investigating mental function in humans and new drugs for the treatment of mental disorders . Involvement of extracellular signal-regulated kinase module in HIV-mediated P01730 signals controlling activation of nuclear factor-kappa B and AP-1 transcription factors . Although the molecular mechanisms by which the HIV-1 triggers either T cell activation , anergy , or apoptosis remain poorly understood , it is well established that the interaction of HIV-1 envelope glycoproteins with cell surface P01730 delivers signals to the target cell , resulting in activation of transcription factors such as NF-kappa B and AP-1 . In this study , we report the first evidence indicating that kinases MEK-1 ( Q96HU1 kinase/Erk kinase ) and P27361 ( extracellular signal-regulated kinase ) act as intermediates in the cascade of events that regulate NF-kappa B and AP-1 activation upon HIV-1 binding to cell surface P01730 . We found that CEM cells transfected with dominant negative forms of MEK-1 or P27361 do not display NF-kappa B activation after HIV-1 binding to P01730 . In contrast , NF-kappa B activation was observed in these cells after PMA stimulation . Although the different cell lines studied expressed similar amounts of P01730 and p56(lck) , HIV-1 replication and HIV-1-induced apoptosis were slightly delayed in cells expressing dominant negative forms of MEK-1 or P27361 compared with parental CEM cells and cells expressing a constitutively active mutant form of MEK-1 or wild-type P27361 . In light of recently published data , we propose that a positive signal initiated following oligomerization of P01730 by the virus is likely to involve a recruitment of active forms of p56(lck) , P04049 , MEK-1 , and P27361 , before AP-1 and NF-kappa B activation . Delta 9-tetrahydrocannabinol induces the apoptotic pathway in cultured cortical neurones via activation of the P21554 receptor . Delta 9-tetrahydrocannabinol , the principal psychoactive component of marijuana , exerts a variety of effects on the CNS , including impaired cognitive function and neurobehavioural deficits . The mechanisms underlying these neuronal responses to tetrahydrocannabinol are unclear but may involve alterations in neuronal viability . DB00470 has been shown to influence neuronal survival but the role of the cannabinoid receptors in the regulation of neuronal viability has not been fully clarified . In this study we demonstrate that tetrahydrocannabinol promotes the release of cytochrome c , activates caspase-3 , promotes cleavage of the DNA repair enzyme poly-ADP ribose polymerase and induces DNA fragmentation in cultured cortical neurones . These effects of tetrahydrocannabinol were completely abrogated by the CB(1) receptor antagonist AM-251 . The findings of this study demonstrate that tetrahydrocannabinol induces apoptosis in cortical neurones in a manner involving the P21554 subtype of cannabinoid receptor . Eupolyphaga sinensis walker displays inhibition on hepatocellular carcinoma through regulating cell growth and metastasis signaling . Tumor growth and metastasis are responsible for most cancer patients ' deaths . Here , we report that eupolyphaga sinensis walker has an essential role in resisting hepatocellular carcinoma growth and metastasis . Compared with proliferation , colony formation , transwell assay and transplantable tumor in nude mouse in vitro and vivo , eupolyphaga sinensis walker extract ( ESWE ) showed good inhibition on the SMMC-7721 cell growth and metastasis . Using genome-wide microarray analysis , we found the down-regulated growth and metastasis factors , and selected down-regulated genes were confirmed by real-time PCR . Knockdown of a checkpoint PKCβ by siRNA significantly attenuated tumor inhibition and metastasis effects of ESWE . Moreover , our results indicate ESWE inhibits HCC growth by not only downregulating the signaling of PKCβ , Akt , m-TOR , Erk1/2 , MEK-2 , Raf and JNK-1 , but also increasing cyclin D1 protein levels and decreasing amount of cyclin E , cyclin B1 and cdc2 of the cycle proteins . At the same time , ESWE reduced P08253 , P14780 and P61073 , P00747 , NFκB and P04637 activities . Overall , our studies demonstrate that ESWE is a key factor in growth and metastasis signaling inhibitor targeting the PKC , AKT , MAPK signaling and related metastasis signaling , having potential in cancer therapy . delta 9- DB00470 increases activity of tyrosine hydroxylase in cultured fetal mesencephalic neurons . The exposure of pregnant rats to delta 9-tetrahydrocannabinol ( delta 9-THC ) , the main psychoactive constituent of Cannabis sativa , during gestation and lactation , affects the gene expression and the activity of tyrosine hydroxylase ( TH ) in the brain of their offspring , measured at fetal and early postnatal ages , when the expression of this enzyme plays an important role in neural development . In the present article , we have examined whether delta 9-THC is able to affect TH activity in cultured mesencephalic neurons obtained from fetuses at gestational d 14 . Thus , TH activity increased approximately twofold in cells obtained from naive fetuses when exposed for 24 h to medium containing delta 9-THC . In addition , TH activity was also approx twofold higher in cells obtained from fetuses exposed daily to delta 9-THC from d 5 of gestation than in cells obtained from control fetuses , when both were exposed to basal media . This effect of delta 9-THC on TH activity seems to be produced via the activation to cannabinoid receptors , in particular the P21554 subtype , which would presumably be located in these cells . This is because the exposure to medium containing both delta 9-THC and SR141716A , a specific antagonist for P21554 receptors , abolished the effect observed with delta 9-THC alone . SR141716A alone was without effect on TH activity . Collectively , our results support the notion that delta 9-THC increased TH activity in cultured mesencephalic neurons , as previously observed in vivo , and that this effect was produced by activation of P21554 receptors , which seem to be operative at these early ages . All this points to a role for the endogenous cannabimimetic system in brain development . Nicotinic alpha 7 receptors as a new target for treatment of cannabis abuse . Increasing use of cannabis makes the search for medications to reduce cannabis abuse extremely important . Here , we show that homomeric alpha7 nicotinic receptors are novel molecular entities that could be targeted in the development of new drugs for the treatment of cannabis dependence . In rats , systemic administration of the selective alpha7 nicotinic acetylcholine receptor antagonist methyllycaconitine ( MLA ) , but not the selective heteromeric non-alpha7 nicotinic acetylcholine receptor antagonist dihydrobetaerythroidine , ( 1 ) antagonized the discriminative effects of DB00470 ( THC ) , the main active ingredient in cannabis , ( 2 ) reduced intravenous self-administration of the synthetic cannabinoid P21554 receptor agonist WIN55,212-2 [ ( R ) -(+)-[2,3-dihydro-5-methyl-3[(4-morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl)methanone , mesylate salt ] , and ( 3 ) decreased THC-induced dopamine elevations in the shell of the nucleus accumbens . Altogether , our results indicate that blockade of alpha7 nicotinic receptors reverses abuse-related behavioral and neurochemical effects of cannabinoids . Importantly , MLA reversed the effects of cannabinoids at doses that did not produce depressant or toxic effects , further pointing to alpha7 nicotinic antagonists as potentially useful agents in the treatment of cannabis abuse in humans . DB00452 -arginine conjugate , a novel HIV-1 Tat antagonist : synthesis and anti-HIV activities . HIV-1 transactivating protein Tat is essential for virus replication and progression of HIV disease . HIV-1 Tat stimulates transactivation by binding to HIV-1 transactivator responsive element ( TAR ) RNA , and while secreted extracellularly , it acts as an immunosuppressor , an activator of quiescent T-cells for productive HIV-1 infection , and by binding to CXC chemokine receptor type 4 ( P61073 ) as a chemokine analogue . Here we present a novel HIV-1 Tat antagonist , a neomycin B-hexaarginine conjugate ( NeoR ) , which inhibits Tat transactivation and antagonizes Tat extracellular activities , such as increased viral production , induction of P61073 expression , suppression of CD3-activated proliferation of lymphocytes , and upregulation of the CD8 receptor . Moreover , Tat inhibits binding of fluoresceine isothiocyanate ( FITC ) -labeled NeoR to human peripheral blood mononuclear cells ( PBMC ) , indicating that Tat and NeoR bind to the same cellular target . This is further substantiated by the finding that NeoR competes with the binding of monoclonal Abs to P61073 . Furthermore , NeoR suppresses HIV-1 binding to cells . Importantly , NeoR accumulates in the cell nuclei and inhibits the replication of M- and T-tropic HIV-1 laboratory isolates ( EC(50) = 0.8-5.3 microM ) . A putative model structure for the TAR-NeoR complex , which complies with available experimental data , is presented . We conclude that NeoR is a multitarget HIV-1 inhibitor ; the structure , and molecular modeling and dynamics , suggest its binding to TAR RNA . NeoR inhibits HIV-1 binding to cells , partially by blocking the P61073 HIV-1 coreceptor , and it antagonizes Tat functions . NeoR is therefore an attractive lead compound , capable of interfering with different stages of HIV infection and AIDS pathogenesis . Actions of DB00470 in cannabis : relation to use , abuse , dependence . Cannabis use disorders have been recently identified as a relevant clinical issue : a subset of cannabis smokers seeks treatment for their cannabis use , yet few succeed in maintaining long-term abstinence . The rewarding and positive reinforcing effects of the primary psychoactive component of smoked cannabis , DB00470 ( THC ) are mediated by the cannabinoid P21554 receptor . The P21554 receptor has also been shown to mediate cannabinoid dependence and expression of withdrawal upon cessation of drug administration , a phenomenon verified across species . This paper will review findings implicating the P21554 receptor in the behavioural effects of exogenous cannabinoids with a focus on cannabinoid dependence and reinforcement , factors that contribute to the maintenance of chronic cannabis smoking despite negative consequences . Opioidergic modulation of these effects is also discussed . Effect of (-)-Delta(9)-tetrahydrocannabinoid on the hepatic redox state of mice . (-)-Delta(9)- DB00470 ( Delta(9)-THC ) , a psychoactive component of marijuana , has been reported to induce oxidative damage in vivo and in vitro . In this study , we administered Delta(9)-THC to healthy C57BL/6J mice aged 15 weeks in order to determine its effect on hepatic redox state . Mice were divided into 3 groups : Delta(9)-THC ( N = 10 ) , treated with 10 mg/kg body weight Delta(9)-THC daily ; VCtrl ( N = 10 ) , treated with vehicle [ 1:1:18 , cremophor EL ( polyoxyl 35 castor oil ) /ethanol/saline ] ; Ctrl ( N = 10 ) , treated with saline . Animals were injected ip twice a day with 5 mg/kg body weight for 10 days . Lipid peroxidation , protein carbonylation and DNA oxidation were used as biomarkers of oxidative stress . The endogenous antioxidant defenses analyzed were glutathione ( DB00143 ) levels as well as enzyme activities of superoxide dismutase , catalase , glutathione S-transferase , glutathione reductase , and glutathione peroxidase ( GPx ) in liver homogenates . The levels of mRNA of the cannabinoid receptors P21554 and CB2 were also monitored . Treatment with Delta(9)-THC did not produce significant changes in oxidative stress markers or in mRNA levels of P21554 and CB2 receptors in the liver of mice , but attenuated the increase in the selenium-dependent GPx activity ( Delta(9)-THC : 8 % ; VCtrl : 23 % increase ) and the DB00143 /oxidized DB00143 ratio ( Delta(9)-THC : 61 % ; VCtrl : 96 % increase ) , caused by treatment with the vehicle . Delta(9)-THC administration did not show any harmful effects on lipid peroxidation , protein carboxylation or DNA oxidation in the healthy liver of mice but attenuated unexpected effects produced by the vehicle containing ethanol/cremophor EL . Virus isolates during acute and chronic human immunodeficiency virus type 1 infection show distinct patterns of sensitivity to entry inhibitors . We studied the effect of entry inhibitors on 58 virus isolates derived during acute and chronic infection to validate these inhibitors in vitro and to probe whether viruses at early and chronic disease stages exhibit general differences in the interaction with entry receptors . We included members of all types of inhibitors currently identified : ( i ) agents that block gp120 binding to P01730 ( P01730 -IgG2 and monoclonal antibody [ MAb ] IgG1b12 ) , ( ii ) compounds that block the interaction with P51681 ( the chemokine RANTES/ P13501 , the small-molecule inhibitor AD101 , and the anti- P51681 antibody PRO 140 ) , ( iii ) the fusion inhibitor enfuvirtide ( T-20 ) , and ( iv ) neutralizing antibodies directed against gp120 ( MAb 2G12 ) and gp41 ( MAbs 2F5 and 4E10 ) . No differences between viruses from acute and chronic infections in the susceptibility to inhibitors targeting the P01730 binding site , P51681 , or fusion or to MAb 2G12 were apparent , rendering treatment with entry inhibitors feasible across disease stages . The notable exceptions were antibodies 2F5 and 4E10 , which were more potent in inhibiting viruses from acute infection ( P = 0.0088 and 0.0005 , respectively ) , although epitopes of these MAbs were equally well preserved in both groups . Activities of these MAbs correlated significantly with each other , suggesting that common features of the viral envelope modulate their potencies . Cannabis-induced cytotoxicity in leukemic cell lines : the role of the cannabinoid receptors and the MAPK pathway . Delta9- DB00470 ( THC ) is the active metabolite of cannabis . THC causes cell death in vitro through the activation of complex signal transduction pathways . However , the role that the cannabinoid 1 and 2 receptors ( P21554 -R and CB2-R ) play in this process is less clear . We therefore investigated the role of the CB-Rs in mediating apoptosis in 3 leukemic cell lines and performed microarray and immunoblot analyses to establish further the mechanism of cell death . We developed a novel flow cytometric technique of measuring the expression of functional receptors and used combinations of selective P21554 -R and CB2-R antagonists and agonists to determine their individual roles in this process . We have shown that THC is a potent inducer of apoptosis , even at 1 x IC(50) ( inhibitory concentration 50 % ) concentrations and as early as 6 hours after exposure to the drug . These effects were seen in leukemic cell lines ( CEM , HEL-92 , and HL60 ) as well as in peripheral blood mononuclear cells . Additionally , THC did not appear to act synergistically with cytotoxic agents such as cisplatin . One of the most intriguing findings was that THC-induced cell death was preceded by significant changes in the expression of genes involved in the mitogen-activated protein kinase ( MAPK ) signal transduction pathways . Both apoptosis and gene expression changes were altered independent of p53 and the CB-Rs . 17 DB00783 -mediated growth inhibition of MDA-MB-468 cells stably transfected with the estrogen receptor : cell cycle effects . P03372 ( ER ) -negative MDA-MB-468 human breast cancer cells were stably transfected with wild-type human ER and utilized as a model for investigating estrogen- and aryl hydrocarbon ( Ah ) -responsiveness . Treatment of the stably transfected cells with 10 nM 17 beta-estradiol ( E2 ) resulted in a significant inhibition ( > 60 % ) of cell proliferation and DNA synthesis , which was blocked by 10(-7) M ICI 182 780 . Analysis by flow cytometry indicated that treatment with E2 increased the percentage of cells in G0/ P55008 ( from 68.8 to 89.4 ) and decreased cells in S ( from 18.4 to 3.4 ) and G2/M ( from 12.8 to 7.2 ) phases of the cell cycle . The effects of E2 on the major cyclins , cyclin-dependent kinases and cyclin-dependent kinase inhibitors , retinoblastoma protein ( RB ) , Q01094 , and cyclin-dependent kinase activities were also investigated in the stably transfected MDA-MB-468 cells . The results demonstrated that the growth inhibitory effects of 10(-8) M E2 in ER stably transfected MDA-MB-468 cells were associated with modulation of several factors required for cell cycle progression and DNA synthesis , including significant induction of the cyclin-dependent kinase inhibitor p21cip-1 ( > 4-fold increase after 12 h ) and decreased Q01094 and P12004 protein levels . These results show that the growth-inhibitory effects of E2 in the stably transfected cells were due to multiple factors which result in growth arrest in G0/ P55008 and inhibition of DNA synthesis . Additive antiemetic efficacy of low-doses of the cannabinoid CB(1/2) receptor agonist Δ(9)-THC with ultralow-doses of the vanilloid Q8NER1 receptor agonist resiniferatoxin in the least shrew ( Cryptotis parva ) . Previous studies have shown that cannabinoid P21554 /2 and vanilloid Q8NER1 agonists ( DB00470 ( Δ(9)-THC ) and resiniferatoxin ( RTX ) , respectively ) can attenuate the emetic effects of chemotherapeutic agents such as cisplatin . In this study we used the least shrew to demonstrate whether combinations of varying doses of Δ(9)-THC with resiniferatoxin can produce additive antiemetic efficacy against cisplatin-induced vomiting . RTX by itself caused vomiting in a bell-shaped dose-dependent manner with maximal vomiting at 18 μg/kg when administered subcutaneously ( s.c. ) but not intraperitoneally ( i.p. ) . Δ(9)-THC up to 10 mg/kg provides only 80 % protection of least shrews from cisplatin-induced emesis with an ID50 of 0.3-1.8 mg/kg . Combinations of 1 or 5 μg/kg RTX with varying doses of Δ(9)-THC completely suppressed both the frequency and the percentage of shrews vomiting with ID50 dose values 5-50 times lower than Δ(9)-THC doses tested alone against cisplatin . A less potent Q8NER1 agonist , capsaicin , by itself did not cause emesis ( i.p. or s.c. ) , but it did significantly reduce vomiting induced by cisplatin given after 30 min but not at 2 h . The Q8NER1 -receptor antagonist , ruthenium red , attenuated cisplatin-induced emesis at 5mg/kg ; however , another Q8NER1 -receptor antagonist , capsazepine , did not . In summary , we present evidence that combination of P21554 /2 and Q8NER1 agonists have the capacity to completely abolish cisplatin-induced emesis at doses that are ineffective when used individually .