苯妥英对局灶性脑缺血-再灌注后脑组织NO水平的影响

目的:本实验通过观察大鼠局灶性脑缺血-再灌注后脑组织一氧化氮(NO)水平的变化以及苯妥英(PHT)对其影响,以进一步探讨局灶性脑缺血-再灌注损伤机制及PHT对缺血-再灌注损伤后保护作用的机制。方法:将雄性成年Wistar大鼠随机分为4组:即假手术组、缺血-再灌注组、PHT低剂量治疗组和PHT高剂量治疗组。每组均观察手术后6h、12h、24h三个时间点的改变。采用线栓法制成大脑中动脉闭塞模型。测定手术后不同时点缺血脑组织NO的水平。结果:缺血-再灌注组各时点NO水平与假手术组相应时点比较明显升高,具有显著性差异(P<0.05),PHT低剂量治疗组和高剂量治疗组NO水平明显低于缺血-再灌注组各相应时间点(P<0.05),PHT高剂量治疗组各时点NO水平与PHT低剂量治疗组各相应时间点比较明显降低(P<0.05)。结论:脑缺血-再灌注后,缺血大鼠脑组织内的NO水平升高,说明NO参与了脑缺血-再灌注损伤的病理生理过程;PHT可降低NO水平,从而对脑缺血-再灌注损伤可能具有保护作用。

Effect of phenytoin on nitric oxide after cerebral ischemia-reperfusion in rats

Objective: To explore the protective effect of phenytoin on experimental cerebral ischemia-reperfusion injury of rats and the possible mechanism. Methods: The model of focal brain ischemia was prod-uced by an intralumin al suture occulusion of the middle cerebral artery ( MCA ) in rats. 60 adult male wistar rats were used. The rats were randomly divided into four groups:sham operation group undergoing all surgical procedures but the intraluminal suture occulusion of the middle cerebral artery, ischemia-reperfusion group,two treatment groups (phenytion at 20mg/kg,40mg/kg).Every group was divided into 3 various stages: post operation 6h,12h, 24h. The level of nitric oxide (NO) was analyzed by spectrophotometry.Results: The level of NO at various stage in ischemia-reperfusion group were higher than those in sham operation group (P <0.05 ). Those of NO at various stages in phenytion (20mg/kg, 40mg/kg, ip)treatment groups were lower than those in ischemia-reperfusion group(P <0.05).The levels of NO at various stages in phenytion(40mg/kg,ip)treatment group were lower than those in phenytion(20mg/kg, ip) treatment group(P <0.05). Conclusion: The levels of NO of rats in ischemia-reperfusion group were notably increased. It showed that NO played a role in the physicological functions of ischemia-reperfusion injury. Phenytion reduced the levels of NO.