大白鼠小肠缺血再灌注后肾脏组织中凋亡基因表达与超微结构改变

The changes in expression of apoptotic gene and ultrastructures in the rat kidney after intestinal ischemia and reperfusion

目的:探讨大白鼠小肠缺血再灌注后肾脏组织的次级损伤和改变。方法:建立小肠缺血再灌注模型,于缺血再灌注前及再灌注后03、0 min,1、2 h,1、3、7天采取静脉血并切取脏肾组织块;用化学法检测一氧化氮(NO)和超氧化物歧化酶(SOD)血中含量,用免疫组织化学SP法和透射电镜分别观察肾脏组织中Bax、Bcl-2、p53的表达及细胞超微结构的改变情况。结果:小肠缺血再灌注后NO浓度有所升高(P<0.01),而SOD浓度呈下降趋势(P<0.01)。Bax、Bcl-2及p53免疫阳性细胞率于再灌注0 min开始升高,依次为(3.35±1.43)%,(2.86±0.56)%,(1.58±0.32)%;至30 min时,三者阳性细胞率升高更为明显,依次为(13.38±3.65)%,(22.25±4.82)%,(6.31±2.24)%,但Bcl-2表达高于Bax(P<0.01)。再灌注2 h时,三种基因的表达均有所降低,其后又开始升高,7天时阳性细胞率达高峰,依次为(59.85±8.25)%,(40.75±6.27)%,(36.45±4.98)%,但Bax表达明显高于Bcl-2。电镜观察发现肾小管基底膜破裂,上皮坏死脱落等。结论:大鼠小肠缺血再灌注后可引起肾脏组织细胞的凋亡和损伤。

Objective：To study the second injury in the kidney after intestinal ischemia and reperfusion. Methods： A model of ischemia and reperfusion of small intestine was made according to the literature. Blood sample and kidney tissue sample were collected before clamp the artery and at 0, 30min, 1, 2 h, 1, 3, 7 d after reperfusion, the changes of the concentration of nitric oxide （NO） and superoxide dismutase （SOD）were examined by the chemical method, expression of Bax, Bcl-2, p53 and uhrastructures of kidney tissue were observed by immunohistochemical SP method and transmission electron microscopy. Results：The concentration of NO increased after ischemia and reperfusion. For SOD, the concentration decreased gradually from reperfusion 0 min to 7 d. The ratio of positive cells of Bax, Bcl-2 and p53 increased after ischemia and reperfusion, and the ratio of positive cells of Bcl-2 was higher than that of Bax. After ischemia and reperfusion for 2 h the expression of Bax, Bcl-2, p53 decreased apparently, then increased continuously to 7 d when it reached a peak and the ratio of Bax was higher than that of Bcl-2（ P〈0.01）. The result of transmission electron microscopy showed the rupture of the renal tubule basement membrane, epithelium necrosis and exfoliation. Conclusions： Intestinal ischemia and reperfusion can induce apoptosis and second injury of renal tissue and cells.