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

Effect of myocardial reperfusion on cardiocyte apoptosis and expression of bcl -2,box and caspase -3 in rats with depression

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 the effect of ischemia/reperfusion（I/R） on cardiac myocyte apoptosis and the expression of bcl -2,bax and caspase -3 in the rats with depression.METHODS：Thirty-two Wistar rats were randomly divided into 4 groups,including group A：sham operation group;group B：the rats with depression undergoing sham operation; group C：the rats with myocardial I/R operation;group D：the rats with depression undergoing myocardial I/R operation. The rat model of depression was produced by chronic mild unpredictable stress and separation.The behaviors of the rats were detected by open field test and fluid consumption test.The myocardial I/R model was made by ligating the left anterior descending branch of coronary artery in the rats.The apoptotic cardiomyocytes were detected by in situ TdT-mediated dUTP nick end labeling（TUNEL） method,and the expression of bcl -2,bax and caspase -3 was detemined by the methods of immunohistochemistry and reverse transcription polymerase chain reaction（RT-PCR）.RESULTS：Compared with group A and group B,the numbers of apoptotic cardiomyocytes in group C and group D were significantly increased（P 0.01）,and the 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 with group C,the number of apoptotic cardiomyocytes 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 significandy increased （P〈0.05）.CONCLUSION：Myocardial reperfusion increases apoptosis in ischemic cardiomyocytes in the rats with depression. The mechanisms may be associated with up-regulating the gene expression of bax and caspase-3 while downregulating bcl -2 expression.