犬小肠缺血再灌注血管内皮细胞Bcl—2、Bax和VEGF的表达及意义

目的；研究犬小肠缺血再灌注后血管内皮细胞中的凋亡基因（Bcl-2,Bax)的血管内皮生长因子（VEGF）表达改变和意义。方法：阻断分布于小肠较小范围的小肠动脉，建立小肠缺血再灌注模型。以免疫组织化学方法对小肠组织中的Bcl-2,Bax和VEGF的表达进行观察研究。结果：小肠缺血再灌注后，Bcl-2,Bax和VEGF的表达有明显的改变。小肠再灌注0min,Bcl-2,Bax和VEGF的阳性细胞率分别为85％、55％和10％，再灌注30min ,分别为66％、54％和65％，而至再灌注60min，则分别为44％、75％和5％，在对照组仅有少量阳性细胞。结论：小肠缺血再灌注可引起抗凋亡基因Bcl表达夺加，但随着血流恢复而逐渐减少，而凋亡基因Bax的表达则逐渐增加。VEGF表达虽有一定增加，但最终减少。小肠缺血再灌注能增强调亡基因表达和诱导凋亡。

The expression and its significance of apoptotic gene and VEGF in intestinal endothelial cells after ischemia-reperfusion of the dogs

Objective To investigate the expression and its significance of Bcl-2, Bax and vascular endothelial growth factor (VEGF) in intestinal ischemia and reperfusion injury. Methos The ischemia and reperfusion models were established by clamping the intestinal artery distributing in small area, and the expression of Bcl-2, Bax and VEGF were studied in intestinal tissues by immunohistochemical method. Results The changes of expression of Bcl-2, Bax and VEGF in intestine after ischemia and reperfusion were obvious. After reperfusion for 0 min, the positive cell ratio of Bcl-2, Bax and VEGF was 85% , 55% and 10%, for 30 min and 60 min, that was 66% , 54% , 65% and 44%, 75% , 5% respectively. There was only a small number of positive cells in control animals. Conclusion Ischemia and reperfusion could increase the expression of anti-apoptotic gene Bcl-2 and VEGF at early stage, but it decreases when the blood flow recovered, the expression of apoptotic gene Bax increases continuously. Intestinal ischemia and reperfusion injury might play an important role in increasing the expression of apoptotic gene and induces the apoptosis.