心肌再灌注对抑郁大鼠心肌细胞凋亡以及bcl-2、bax和caspase-3表达的影响

摘要

目的:探讨心肌缺血再灌注(I/R)对抑郁大鼠心肌细胞凋亡及凋亡基因bcl-2、bax和caspase-3的影响.方法:Wistar大鼠32只,随机分为4组,每组各8只.A组:非抑郁大鼠假手术组;B组:抑郁大鼠假手术组;C组:非抑郁大鼠心肌I/R组;D组:抑郁大鼠心肌I/R组.采用慢性轻度不可预知性应激结合孤养制备抑郁模型,用敞箱实验和液体消耗实验观察大鼠行为改变;运用结扎左冠状动脉前降支的方法复制心肌I/R模型.运用TUNEL法检测心肌凋亡细胞;运用免疫组化法和逆转录-聚合酶链反应(RT- PCR)方法检测bcl-2、bax和caspase-3的表达.结果:(1)与A、B组比较,C、D组心肌细胞凋亡数量显著增加(P<0.01),A、B两组间比较无显著差异;与C组比较,D组心肌细胞凋亡数量显著增加(P<0.05).(2)与A、B组比较,C、D组Bcl-2、Bax和caspase-3蛋白和mRNA表达显著增加(P<0.01),A、B两组间比较无显著差异;与C组比较,D组Bcl-2蛋白和mRNA表达显著减少(P<0.05),而Bax和caspase-3蛋白和mRNA表达显著增加(P<0.05).结论:心肌缺血再灌注可加重抑郁大鼠缺血心肌细胞凋亡,其机制可能与上调bax和caspase-3基因表达、下调bcl-2基因表达有关.%AIM:To explore ihe effecl of ischemia/reperfusion (I/R) on cardiac myocyle apoplosis and ihe expression of bcl -2, bax and caspase - 3 in ihe rals wilh depression. METHODS; Thirty - Lwo Wislar rals were randomly divided inlo 4 groups,including group A; sham operation group; group B; ihe rals wilh depression undergoing sham opera-lion; group C; ihe rals wilh myocardial I/R operalion; group D; ihe rals wilh depression undergoing myocardial I/R opera-lion. The ral model of depression was produced by chronic mild unpredictable slress and separalion. The behaviors of ihe rals were delecled by open field lesl and fluid consumption lesl. The myocardial I/R model was made by ligaling ihe lefl an-lerior descending branch of coronary artery in ihe rals. The apoplolic cardiomyocyles were delecled by in siLu TdT - media-led dUTP nick end labeling (TUNEL) melhod, and ihe expression of bcl -2, bax and caspase - 3 was delemined by ihe melhods of immunohislochemislry and reverse Iranscriplion polymerase chain reaction ( RT - PCR) . RESULTS; Compared wilh group A and group B, ihe numbers of apoplolic cardiomyocyles in group C and group D were significantly increased (P < 0. 01) , and ihe expression of bcl - 2, bax and caspase - 3 in group C and group D was also significantly increased ( P < 0. 01). No significant difference between group A and B was observed. Compared wilh group C, the number of apoplolic cardiomyocyles in group D was significantly increased (P < 0. 05). The gene expression of bcl -2 in group D was decreased significantly ( P < 0. 05 ) , while the gene expression of bax and caspase - 3 in group D was significantly increased ( P < 0. 05 ) . CONCLUSION; Myocardial reperfusion increases apoptosis in ischemic cardiomyocyles in the rals with depression. The mechanisms may be associated with up - regulaling the gene expression of bax and caspase - 3 while down - regulaling bcl - 2 expression.