bax、bcl-2在梗阻性黄疸心肌损伤中的表达及意义

Expression and significance of bax and bcl-2 in myocardial tissue injury after obstructive jaundice

目的探讨bax、bcl-2在梗阻性黄疸心肌损伤中的表达及意义。方法健康日本大耳白兔48只,随机分为A、B两组,雌雄各半,A组为胆总管结扎组24只,B组为假手术组24只。建立实验动物模型,将A、B两组再分为3个亚组。所有实验动物均在相同条件下饲养,其中A1、B1组于术后7 d取材,A2、B2组于术后14 d取材,A3、B3组于术后21 d取材。采用原位缺口末端标记法检测心肌细胞凋亡,采用免疫组化法检测心肌组织bax、bcl-2的表达情况。结果A组动物的心肌组织中可见bcl-2和bax蛋白表达,bax蛋白在梗阻14 d达高峰,此后开始下降,而bcl-2蛋白在梗阻21 d达高峰;凋亡指数随bax升高而升高,随bcl-2的升高而降低;B组动物bax、bcl-2表达和AI值极低。结论梗阻性黄疸所致的心肌组织病理变化可能与凋亡程序启动有关;bcl-2和bax可能对梗阻性黄疸心肌细胞凋亡的调控起着重要作用。

Objective To study the expression and significance of bax and bcl-2 in myocardial tissue injury after obstructive jaundice （O J） in rabbits. Methods 48 rabbits were randomly di- vided into two groups： the group of OJ （group A, 24 rabbits） and the group of sham-operation （group B, 24 rabbits）, then each group were further subdivided into 4 subgroups： A1, A2, A3; B1, B2, B3, respectively. There were 8 rabbits in each subgroup. All rabbits were raised under the same condition. Myocardial cell apoptosis was examined by in situ end-labeled DNA. The expressions of bax and bcl-2 in myocardial tissue were detected by immunohistochemistry. Results Expressions of bcl-2 and bax in myocardial tissue could be observed in group A. The expression of bax reached its peak value at the 14th day after OJ, and then declined. Similarly, the highest expression of bcl-2 was observed at the 21st day after OJ. The apoptosis index increased with the increase of bax expression but decreased with bcl-2 strong expression. There were few expressions of bax and bcl-2 in group B. Conclusion The pathology of myocardial tissue following OJ may be related to the activation of apoptosis, and bax as well as bcl-2 may play an important role in the control of apoptosis of myocardial tissue after OJ.