苯并[a]芘亚急性染毒对雄性Wistar大鼠心血管的影响

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

目的探讨苯并[a]芘(B[a]P)腹腔注射亚急性染毒对雄性Wistar大鼠心血管的影响。方法将10~11周SPF级雄性Wistar大鼠40只按体重随机分为空白对照组,溶剂对照组,低、中、高剂量染毒组(B[a]P浓度分别为1.0、2.5和6.25 mg/kg),每组8只。溶剂对照组给予1.0 mL/kg的橄榄油,空白对照组不做任何处理,连续28天。染毒结束后用Prospect 3.0小动物超声成像仪和BL-410生物机能实验系统观察其左心室结构功能和血流动力学改变。HE染色观察大鼠胸主动脉和左心室病理变化。结果染毒后各组大鼠射血分数(ejection fraction, EF)、左室短轴缩短率(fractinanal shortening, FS)和左室舒张末压(left ventricular end diastolic pressure, LVEDP)总体差异有统计学意义(H=11.497,P=0.022;H=11.422,P=0.022;H=10.104,P=0.039),中剂量组EF及FS低于溶剂组(调整后P<0.05),高剂量组大鼠LVEDP高于溶剂组(调整后P<0.05)。中、高剂量组胸主动脉HE染色显示血管内膜部分缺失,部分内皮细胞脱落,内膜下胶原暴露,中膜层间隙较大;中、高剂量组左室横纹模糊不清,肌纤维减少断裂或消失,心肌间隙增宽,偶见炎症细胞或有心肌间隙渗血现象。结论苯并[a]芘可致雄性Wistar大鼠心血管功能和内皮发生损伤。

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.