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[Effects of benzo[a]pyrene subacute administrate on the cardiovascular of male Wistar rats].

OBJECTIVE
To explore subacute toxic effects of benzo[a]pyrene on the cardiovascular system of male Wistar rats.


METHODS
Forty SPF grade male Wistar rats were randomly divided into blank control group, solvent control group, low, medium and high dose group(B[a]P concentrations were 1. 0, 2. 5 and 6. 25 mg/kg, respectively), eight in each group. The solvent group was given the same amount of olive oil and the blank group was not treated at all for 28 consecutive days. After the end of the exposure, the left ventricular structural function and hemodynamic changes were observed with Prospect 3. 0 small animal ultrasound imager and BL-410 biological function test system. Pathological changes of rat thoracic aorta and left ventricle were observed by HE staining.


RESULTS
The total difference in ejection fraction(EF), fractional shortening(FS) and left ventricular end diastolic pressure(LVEDP) between the groups was statistically significant(H=11. 497, P=0. 022; H=11. 422, P=0. 022; H=10. 104, P=0. 039). The EF and FS of the middle dose group were lower than the solvent group(adjusted P<0. 05), the LVEDP of the high dose group was higher than that of the solvent group(adjusted P<0. 05). The HE staining of thoracic aorta in the medium and high dose groups showed the loss of endothelial cells, the shedding of some endothelial cells, the exposure of subintimal collagen, the large gap of the middle layer. In the medium and high dose group, left ventricular transverse striations were blurred, muscle fibers reduced or disappeared, the myocardial space widened, inflammatory cells or the myocardial interspace bleeding phenomenon was occasionally observed.


CONCLUSION
Benzo[a]pyrene can cause cardiovascular and endothelial damage in male Wistar rats.