Somatostatin inhibits insulin and glucagon secretion. It also inhibits lipolysis and stimulates the secretion of adiponectin. Phosphate is another inhibitor which competitively inhibits alkaline phosphatase. Corticosterone both inhibits protein synthesis and degrades proteins. This G protein-coupled receptor inhibits adenylyl cyclase activity. Activation of increases production via adenylyl cyclase activation and inhibits monoamine transporter function. It also inhibits metabolism of other drugs requiring oxidative metabolism. Estrogen promotes branching differentiation, whereas in males testosterone inhibits it. It also inhibits another metabolizing enzyme, cytochrome CYP2D6. It reversibly inhibits NMDAR-mediated ion currents. In addition, it inhibits apoptosis, therefore accelerating existing cancers. However, serotonin also inhibits osteoblasts, through 5-HT1B receptors. Once a receptor is active, it inhibits adjacent receptors. Follistatin inhibits Activin, which it binds. Finally, in addition to improving overall protein integrity, Hsp70 directly inhibits apoptosis.