盐酸戊乙奎醚预处理对大鼠局灶脑缺血再灌注损伤及凋亡相关基因caspase-3的影响

目的:观察盐酸戊乙奎醚预处理对大鼠局灶脑缺血再灌注损伤的影响及作用机制。方法:将60只雄性SD大鼠随机分为 3 组(每组20只)。对照组（C组）：进行假手术操作，未使用线栓法建立局灶脑缺血模型；缺血-再灌注组（I-R组）：麻醉前30 min腹腔内注射生理盐水2.0 mg•kg^-1后，使用线栓法建立大鼠局灶脑缺血模型，缺血120 min后进行再灌注；盐酸戊乙奎醚预处理组（P组）：麻醉前30 min腹腔内注射盐酸戊乙奎醚2.0 mg•kg^-1后，用线栓法建立大鼠局灶脑缺血模型，缺血120 min后进行再灌注。氯化三苯基四氮唑(TTC)染色观察测定脑梗塞体积；HE 染色法观察大鼠海马神经细胞形态的变化；半定量RT-PCR法测定海马组织caspase-3 mRNA的表达水平。结果:与I-R组比较，P组脑梗塞体积显著减小（P< 0.05）；I-R组海马神经细胞发生严重损伤，细胞核固缩、浓染，P组海马神经细胞损伤显著减轻；I-R组和P组caspase-3 mRNA表达水平明显高于C组（P< 0.05），但P组caspase-3 mRNA表达水平低于I-R组（P< 0.05）。结论：盐酸戊乙奎醚预处理可以显著改善大鼠局灶脑缺血再灌注后海马神经细胞损伤，从而对脑缺血再灌注损伤发挥保护作用，这种保护作用可能与盐酸戊乙奎醚抑制大鼠脑海马组织凋亡蛋白酶caspase-3 mRNA的表达有关。

Effects of penehyclidine hydrochloride pretreatment on transient focal cerebral ischemia/reperfusion injury and expression of caspase-3 in rats

Objective To investigate the protective effect of penehyclidine hydrochloride pretreatment on focal cerebral ischemia/reperfusion injury and expression of caspase-3 in rats.Methods Sixty male Sprague-Dawley rats weighing 250-300 g were randomly divided into 3 groups(n=20): control (C) group in which sham operation was performed; ischemia-reperfusion (I-R)group, in which saline (2.0 mg·kg-1)was administered for intraperitoneal injection 30 min before anesthesia,then the ischemia model was made by occlusion of the left middle cerebral artery for 120 min; penehyclidine hydrochloride pretreatment (P) group, in which penehyclidine hydrochloride(2.0 mg·kg-1)was administered for intraperitoneal injection 30 min before anesthesia,then the same 120 min focal cerebral ischemia was performed as described in I-R group.At the end of 24 h reperfusion the animals were decapitated and the brains were removed.The volume of cerebral infarction was detected with TTC staining;Coronal sections including hippocampal tissue were obtained for HE staining.The levels of caspase-3 mRNA expression in hippocampus were detected by using semi-quantitative RT-PCR technique.Results Compared with group I-R,the volume of cerebral infarction in group P were reduced significantly(P< 0.05);In group P,edema,degeneration and necrosis of nerve cells in the hippocampus of the rats were significantly decreased; The expressions of caspase-3 mRNA in group I-R and group P increased significantly compared with group C(P< 0.05),and the caspase-3 mRNA expression in group P was lower than that in group I-R(P< 0.05).Conclusion Penehyclidine hydrochloride has brain protective effect on focal cerebral ischemia/reperfusion injury in rats and its mechanism is related to inhibiting the expression of caspase-3 mRNA in hippocampus.