肢体缺血-再灌注损伤时细胞凋亡的变化及阿魏酸钠保护作用

目的：阐明氧自由基与细胞凋亡、Bcl-2和Bax蛋白表达在大鼠肢体缺血及再灌注不同时相中的变化规律和相互关系，探讨阿魏酸钠对肢体缺血-再灌注损伤的影响。方法：采用大鼠股动脉夹闭模型，设立缺血组、对照组及阿魏酸钠组，测定肌肉组织中丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性，检测肌肉组织中Bcl-2和Bax蛋白表达的变化，观察细胞凋亡现象。结果：随着再灌注时间的延长(24h内)，氧自由基水平、凋亡指数(AI)及Bax蛋白表达水平进行性升高，阿魏酸钠组三者水平低于对照组；Bcl-2蛋白在短时间内升高，而后逐渐下降，阿魏酸钠组Bcl-2蛋白表达水平的峰值低于对照组，下降也较对照组平缓，至再灌注24h时，阿魏酸钠组Bcl-2蛋白表达水平已高于对照组；氧自由基、Al之间呈显著正相关，氧自由基、Al与Bcl-2／Bax比值呈显著负相关。结论：氧自由基及细胞凋亡同时参与肢体缺血-再灌注损伤，氧自由基可能通过调节Bcl-2／Bax两蛋白的比例关系而发挥其促进细胞凋亡的作用，阿魏酸钠可以有效清除自由基，抑制细胞凋亡，减轻肢体再灌注损伤。

Protection of sodium ferulate for apoptosis of ischemia-reperfusion injury and expression of Bcl-2,Bax protein in rat hind limb

Objective: To interpret the dynamic changes of oxygen derived free radicals,apoptosis and expression of Bcl 2 and Bax protein in rat limb ischemia reperfusion model,analyse their interrelations and the protective effects of sodium ferulate(SF). Methods: Using femoral artery clamped model,the blood stream were occluded for five hours before reperfusion.The changes of ischemia group(ischemia five hours),control group(given salvia miltiorrhiza before reperfusion)and SF group(given SF before reperfusion)were observed by measuring the content of superoxide dismutase(SOD),malondialdehyde(MDA),the expression of Bcl 2 and Bax protein in muscle tissue,and apoptosis. Results: Along with the prolonged time of reperfuring,increasing of oxygen derived free radicals,the expression of Bax protein and apoptosis index(AI) were observed,and the expression of Bcl 2 protein increasing at the beginning,then declining.All parameters except Bcl 2 in SF group were significantly lower than those in control group,and the dynamic change of Bcl 2 was just on the contrary with those parameters.There was a significantly positive correlation between oxygen derived free radicals and AI,and a significantly negative correlation among oxygen derived free radicals,AI and the ratio of Bcl 2/Bax. Conclusion: Oxygen free radicals and apoptosis both participate in limb reperfusion injury.Oxygen free radicals may accelerate the occurrence of apoptosis through regulating the ratio of Bcl 2/Bax.SF may play an important role on alleviating reperfusion injury by a mechanism which correlates to the effect of cleaning free radical,inhibiting the occurrence of apoptosis.