犬小肠缺血再灌注后NO、SOD浓度改变和血管内皮细胞凋亡相关基因表达及其意义

The Concentration Changes of NO,SOD,Expression and Implication of Bcl-2,Bax,VEGF in Intestinal Endothalial Cells and Their Correlation after Ischemia-Reperfusion of Dogs

目的 研究犬小肠缺血再灌注后氧自由基的改变、血管内皮细胞中的Bcl 2、Bax和血管内皮细胞生长因子 (VEGF)表达改变的意义及其相关性。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。检测血中NO(Nu ml)和SOD(μmol L)浓度并以免疫组织化学方法对小肠组织中的Bcl 2、Bax和VEGF的表达及它们的相关性进行观察研究。结果 小肠缺血再灌注后 ,NO和SOD的浓度 ,Bcl 2、Bax和VEGF的表达有明显的改变。小肠再灌注 0min ,NO和SOD的浓度分别是 12和 75 ,Bcl 2、Bax和VEGF的阳性细胞率分别为 85 % ,5 5 %和10 % ,再灌注 30min ,NO和SOD的浓度达最底 (11和 4 3) ,Bcl 2、Bax和VEGF分别为 6 6 %、5 4 %和 6 5 % ,而再灌注 6 0min ,NO和SOD的浓度恢复至 15和 90 ,三种基因的表达则分别为 4 4 %、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NO和SOD浓度降低、Bcl 2和VEGF表达增加 ,但随着血流恢复NO和SOD的浓度有所回升而Bcl 2和VEGF阳性细胞逐渐减少。而凋亡基因Bax的表达则逐渐增加。小肠缺血再灌注能引起氧自由基的增多。

Objective To investigate the changes of oxygen free radical, expression of Bcl 2, Bax, vascular endothelial growth factor(VEGF) and their correlation in intestinal ischemia and reperfusion injury. Method The ischemia and reperfusion models were established by clamping the intestinal artery distributing in small areas, concentration of NO(Nu/ml) and SOD(μ mol/L) was examined, and expressions of Bcl 2,Bax and VEGF in intestinal tissue were studied by means of immunohistochemical method. Results The concentration changes of NO and SOD, and expressions of Bcl 2, Bax and VEGF in intestine after ischemia and reperfusion were obvious. After reperfusion for 0 min, the concentration of NO and SOD was 12 and 75, the positive cell ratios of Bcl 2, Bax and VEGF were 85%,55% and 10%; for 30 min, NO and SOD reached the lowest level (11 and 43),expressions of Bcl 2, Bax and VEGF were 66%, 54%, 65%; for 60 min, the concentration of NO and SOD was 15 and 90, the expressions of Bcl 2, Bax and VEGF were 44%,75%,5% respectively. There was only a small number of positive cells in control animals. Conclusion Ischemia and reperfusion could decrease the concentration of NO and SOD, increase the expressions of Bcl 2 and VEGF at early stage, but the expressions of Bcl 2 and VEGF decreased following the blood flow recovery and the concentration of NO and SOD increasing. The expression of apoptotic gene Bax increased continuously. Intestinal ischemia and reperfusion injury might play an important role in oxygen free radical injury and increasing expression of apoptotic gene, with their obvious correlation.