异丙酚对大鼠前脑缺血-再灌注后海马Caspase-3表达的影响

Effect of propofol on hippocampal Caspase - 3 expression after forebrain ischemia/reperfusion in rats

目的探讨异丙酚对大鼠前脑缺血一再灌注（I／R）后海马Caspase-3表达的影响及在脑保护作用中的机制。方法42只雄性Wistar大鼠随机分为3组，每组14只。双侧颈总动脉夹闭加放血降压再回输法建立前脑I／R模型，侧脑室内注射进行异丙酚干预。对照组（C组）：仅暴露双侧颈总动脉，未放血降压及夹闭双侧颈总动脉；缺血损伤组（I组）：放血法使平均动脉压降到（40±5）mmHg时，夹闭双侧颈总动脉10min，侧脑室内注射生理盐水（1．0mg/kg）；异丙酚干预组（P组）：放血降压、夹闭双侧颈总动脉与I组相同，不同的是侧脑室内注射异丙酚（1．0ms／kg）。=F再灌注24h后断头取脑组织，半定量逆转录一聚合酶链反应（RT—PCR）技术检测海马Caspase-3mRNA表达（n=6），免疫组织化学（IH）法检测海马Caspase-3蛋白表达（n=8）。结果Ⅰ组和P组Caspase-3mRNA表达明显高于C组（P〈0．05），但P组Caspase-3mRNA表达明显低于Ⅰ组（P〈0．05）；Ⅰ组和P组Caspase-3蛋白表达明显高于C组（P〈0．05），但P组Caspase-3蛋白表达明显低于I组（P〈0．05）。结论异丙酚抑制大鼠前脑I／R后海马Caspase-3mRNA和蛋白的表达，可能是其对脑缺血再灌注损伤保护作用的机制之一。

Objective To investigate the effect of propofol on hippocampal Caspase - 3 expression after forebrain ischemia/reperfusion （I/R） in rats and the possible mechanism of protective effect of propofol on brain. Methods Forty - two male Wistar rats weighing 250 - 300 g were randomly divided into 3 groups of 14 animals： in control （C） group, sham operation was performed; in I/R （I） group, bilateral common carotid arteries were clamped for 10 min combined with hypotension [ MAP （40± 5 ）mm Hg] induced by exsanguination, then saline （1.0 mg/kg）was injected into the lateral cerebral ventricle; in propofol （P） group, propofol （ 1.0 mg/kg） was injected into the lateral cerebral ventricle after I/R. At the end of 24 h reperfusion, the animals were decapitated and the brains were removed. The levels of Caspase - 3 mRNA expression in hippocampus were detected by using semi - quantitative RT- PCR technique（ n = 6 ）;Coronal sections including hippocampal tissue were obtained for detection of Caspase - 3 protein expression by immuno - histochemistry method （ n = 8 ）. Results The Caspase -3 mRNA expression in group Ⅰ and P was higher significantly compared with that in group C （ P 〈 0.05 ）, and the Caspase - 3 mRNA expression in group P was lower than that in group Ⅰ（ P 〈 0. 05 ）. The expression of Caspase - 3 protein in group Ⅰ and P was higher significantly compared with that group C （P 〈 0.05 ）, and there was less Caspase- 3 protein expression in group P than in group Ⅰ（P 〈 0.05 ）. Conclusion Forcbrain I/R induces significant increase in the expression of Caspase -3 mRNA and protein in hippocampus of rats. Propofol could inhibit the hippocampal Caspase - 3 mRNA and protein expression after forebrain I/R in rats.