大鼠肠系膜动脉血流短暂阻断对缺血/再灌注心肌细胞凋亡及Bcl-2表达的影响

Effect of brief mesenteric artery occlusion on cardiac myocyte apoptosis and Bcl-2 during myocardial ischemia/reperfusion in rats

目的 :探讨短暂阻断肠系膜动脉血流 (MAO)对大鼠缺血再灌注 (I/R)心肌细胞凋亡及bcl- 2表达的影响。方法 :采用TUNEL法观察心肌细胞凋亡数以及免疫组化和原位杂交方法检测Bcl- 2蛋白及其mRNA表达。结果 :①MAO +IR3h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IR3h组 (P <0 .0 1 ) ;②MAO +IR3h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IR3h组 (P <0 .0 1 ) ;MAO +IR1h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IR1h组 (P <0 .0 1 )。结论 :①大鼠MAO能够显著减少I/R心肌细胞凋亡 ;②MAO通过上调凋亡抑制基因bcl- 2基因表达、提高心肌中Bcl-

AIM: To explore the effect of brief mesenteric artery occlusion (MAO) on cardiac myocyte apoptosis and bcl-2 expression during myocardial ischemia/reperfusion (I/R) in rats. METHODS: TUNEL,immunohistochemical and in situ hybridization(ISH) methods were applied in the present study. RESULTS: ① The numbers of positive cardiac myocyte nuclear and the percentage of positive cardiac myocyte nuclear in MAO+IR 3h group decreased significantly ( P< 0.01) compared with IR 3h group; ② The numbers of protein Bcl-2 positive cardiomyocyte and the percentage of protein Bcl-2 positive cardiomyocyte in MAO+IR 3h group were higher( P< 0.01) than that of IR 3h group,respectively;The numbers of bcl-2 mRNA positive cardiomyocyte and the percentage of bcl-2 mRNA positive cardiomyocyte in MAO+IR 1h group were higher ( P< 0.01) than that of IR 1h group,respectively. CONCLUSIONS: ①Brief MAO could decrease cardiomyocyte apoptosis during I/R significantly.② Up-regulation of the expression of bcl-2 in cardiomyocytes during I/R may be one of the mechanisms responsible for inhibition of cardiomyocyte apoptosis by MAO.