缺血预处理对在体家兔房室结细胞凋亡的影响

Effects of ischemic preconditioning on apoptosis of rabbit atrioventricular node cells in vivo

目的在家兔急性心肌梗死模型中观察缺血预处理(IP)对在体房室结细胞缺血/再灌注(I/R)的作用及Bc l-2和Bax蛋白表达的影响。方法健康家兔40只,随机分5组,假手术组,缺血/再灌注A组和B组,预缺血A组和B组。通过结扎右冠状动脉建立家兔房室结缺血/再灌注模型,观察经过IP后,以不同的再灌注时间30 m in,180m in为实验终点,检测心脏内血液心肌酶学变化,电镜观察超微结构,原位细胞凋亡检测法检测房室结细胞凋亡的变化,免疫组化方法检测Bc l-2和Bax蛋白的表达情况。结果IP组较I/R组,房室结细胞凋亡显著减少(P<0.05),且显著提高了Bc l-2蛋白的表达(P<0.05),降低了Bax蛋白的表达(P<0.05)。结论I/R损伤可诱导房室结细胞凋亡,IP可通过上调Bc l-2蛋白的表达而同时下调Bax蛋白表达,从而减少房室结细胞的凋亡。

AIM To study the effects of ischemic preconditioning （IP） on apoptosis, Bcl-2 and Bax expressions of atrioventricular node （AVN） cells in vivo in ischemic/reperfused rabbits. METHODS The 40 rabbit were divided into 5 groups randomly in this experiment ： sham operate group, I/R A group, I/R B group, IP A group and IP B group. IP and I/R models of AVN cells ischemic-reperfused were established in rabbits by obstructing the right coronary artery. The AST, LDH and CK expressions of blood serum were observed. The uhramicrostructure of AVN cells were observed by perspective electron microscope. Apoptosis AVN cells were detected with TUNEL and Bcl-2 and Bax expressions were detected with immunohistochemistry. RESULTS The expression of apoptotic AVN cells significantly decreased in IP group compared with that in I/R group （P 〈 0.05 ）. Bcl-2 expression significantly increased in IP group compared with that in I/R group （ P 〈 0.05 ） while Bax expression significantly decreased in IP group compared with that in I/R group （P 〈 0.05 ）. CONCLUSION I/R induces and IP reduces AVN cells apoptosis in rabbits. IP increases the Bcl-2 expression and decreases the Bax expression of AVN cells in ischemic/reperfused in rabbits.