大鼠肢体缺血再灌注损伤后细胞凋亡与Bcl-2和Bax蛋白表达的关系

目的：阐明细胞凋亡与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和相互关系。方法：采用大鼠股动脉夹闭模型，阻断股动脉血流5h后进行再灌注。设立缺血组及再灌注组。再灌注组设立1、3、6、12、18、24h6个检测时相，检测肌肉组织中Bcl-2和Bax蛋白表达的变化情况(用免疫组化方法)，观察细胞凋亡现象(用原位末端标记法及电镜方法)。结果：随着再灌注时间的延长(24h内)。凋亡指数(AI)及Bax蛋白表达水平进行性升高，Bcl-2蛋白在短时间内升高，而后逐渐下降，Bcl-2／Bax比值逐渐降低；AI与Bax蛋白表达水平呈显著正相关，与Bcl-2蛋白表达水平呈显著负相关(3～24h)，与Bcl-2／Bax比值呈显著负相关。结论：肢体再灌注损伤的发生有细胞凋亡机制参与，Bcl-2/Bax的比例关系向促进细胞凋亡的方向发展。

The relationship among apoptosis and expression of Bcl-2 and Bax protein in a rat hind limb ischemia reperfusion model

Objective:To elucide the dynamic changes of apoptosis and expression of Bcl-2 and Bax protein in a rat limb ischemia-reperfusion model.Methods: Using femoris artery clamped model, the blood stream were occluded for five hours before reperfusion. 49 rats were devided into ischemia group and reperfusion group. The reperfusion group involved Ih subgroup, 3h subgroup, 6h subgroup, 12h subgroup, 18h subgroup and 24h subgroup. The expression of Bcl-2 and Bax protein in muscle tissue were measured through immunnhistoohemistry, and the apoptosis were observed through TUNEL method and electronic microscope. Results: Increasing of apoptosis index (AI) and the expression of Bax protein were discovered, and the expression of Bel- protein was increased at the beginning, then declined. There was a significantly positive correlation between AI and Bax protein, a significantly negative correlation between AI and Bcl-2 protein, and a significantly negative correlation between AI and the ratio of Bcl-2/Bax. ( P < 0.01). Conclusion: Apoptosis participates in limb reperfusion injury. The ratio of Bcl-2/Bax declines gadually, which accelerate the occurrence of apoptosis.