大鼠心肌缺血预适应对I/R心肌细胞凋亡及bcl-2表达的影响

Effects of ischemic preconditioning on cardiac myocyte apoptosis and expression of bcl-2 during myocardial ischemia/reperfusion in rats

目的 :对缺血预适应 (IP)第一保护窗对大鼠缺血再灌注 (I/R)心肌细胞凋亡和凋亡抑制基因bcl- 2表达的影响进行研究。方法 :采用TUNEL法、免疫组化和原位杂交方法测定大鼠缺血再灌注心肌细胞凋亡和bcl- 2的表达。结果 :①IP +I/R3h组TUNEL法阳性心肌细胞核数量及阳性心肌细胞核占总心肌细胞核数的百分比均明显少于I/R3h组 (P <0 .0 5 ,P <0 .0 1) ;②IP +I/R3h组表达bcl- 2蛋白阳性的心肌细胞数及阳性心肌细胞占心肌细胞总数的百分比均明显高于I/R3h组 (P <0 0 1) ;IP +I/R1h组表达bcl- 2mRNA阳性的心肌细胞数及阳性心肌细胞占心肌细胞总数的百分比均明显高于I/R1h组 (P <0 0 1)。结论 :①大鼠心肌IP第一保护窗能够显著减少I/R心肌细胞凋亡 ;②IP通过上调凋亡抑制基因bcl-

AIM: To explore the effect of ischemic preconditioning on cardiac myocyte apoptosis and the expression of bcl-2 during myocardial ischemia/reperfusion in rats. METHODS: We use TUNEL,immunohistochemical and in situ hybridization(ISH) methods to detect the cardiac myocyte apoptosis and the expression of bcl-2 during myocardial ischemia/reperfusion in rats. RESULTS:① The numbers of positive cardiac myocyte nuclear and the percentage of positive cardiac myocyte nuclear in IP+I/R 3h group decreased significantly(P<0.05,P<0.01) compared with I/R 3h group, respectively. ② The numbers of bcl-2 protein positive cardiomyocyte and the percentage of bcl-2 protein positive cardiomyocyte in IP+I/R 3h group were higher(P<0.01) than that of I/R 3h group,respectively. The numbers of positive bcl-2 mRNA cardiomyocyte and the percentage of positive bcl-2 mRNA cardiomyocyte in IP+I/R 1h group were higher(P<0.01) than that of I/R 1h group,respectively. CONCLUSION: ① The first window of IP's protection could reduce cardiomyocyte apoptosis significantly.② Up-regulating the protein expression of bcl-2 in cardiomyocytes during I/R may be one of the mechanisms of first window of IP's protection.