亚低温缺血预处理对鼠缺血/再灌注肠组织Bcl-2和Bax蛋白表达的影响

Effect of mild hypothermia ischemic - preconditioning on expression of Bcl - 2 and Bax genes in intestine of the rats after gut ischemia-reperfusion injury

目的 探讨亚低温缺血预处理(MHIP)对大鼠缺血/再灌注损伤(I/R)肠组织Bcl-2和Bax蛋白表达的影响。方法 将32只大鼠随机分为4组(每组8只):假手术对照组(sham)、缺血/再灌注组(I/R)、缺血预处理组(IP)、亚低温预处理组(MHIP)。观察各组肠组织超微结构及Bcl-2、Bax蛋白表达。结果 肠缺血/再灌注后小肠组织Bcl-2和Bax蛋白表达光密度值明显增高,与假手术对照组有显著性差异(P<0.01);缺血预处理组与缺血/再灌注组比较及亚低温预处理组与缺血预处理组比较小肠组织Bcl-2蛋白表达光密度值增高(P<0.01,P<0.05),Bax蛋白表达光密度值降低(P<0.01,P<0.05),Bcl-2/Bax光密度比值明显增高。结论 缺血预处理可通过上调Bcl-2基因的蛋白表达与下调Bax基因的蛋白表达,抑制肠缺血/再灌注诱导的细胞凋亡以保护缺血再灌注肠损伤,亚低温能增强缺血预处理的保护作用。

Objective To investigate the effect of mild hypothermia ischemic - preconditioning on expression of Bcl - 2 and Bax genes in intestine of the rats after gut ischemia - reperfusion injury. Methods 32 cases of rats were randomly into four groups: sham operated group (sham), ischemia - reperfusion(I/R) group, ischemic - preconditioning (IP) group, mild hypothermia ischemic - preconditioning(MHIP) group(8 cases in each group). The ultrastructure, Bcl - 2 and Bax protein expression in intestinal mucosa tissue were observed and the data were analyzed by computer analysis system respectively. Results After I/R , the light density value of Bcl - 2 proteins and Bax proteins in creased significantly in I/R group (P < 0.01); the light density value of Bcl - 2 proteins and Bax proteins increased significantly in I/R group (P < O.01); the light density value of Bcl - 2 proteins increased more significantly and Bax proteins decreased more significantly in IP group than in I/R group, and in MHIP group than in IP group(P < 0.01, P < 0.05). The protein expression ratios of Bcl - 2 to Bax increased more significantly in IP group than in I/R group, and in MHIP group than in IP group. Conclusion IP could protect the tissue of intestine from ischemia - reperfusion injury by upregulating the protein expression of Bcl - 2 genes and downregulating the protein expression of Bax genes, reducing myocyte apoptosis, and mild hypothermia might enhance the protective effect of IP on I/R injury in intestine of rats.