缺氧缺血性脑病新生大鼠心肌Caspase-3、Cyt C蛋白表达与心肌细胞凋亡的关系

Relationship between Caspase-3 and Cyt C expression and apoptosis of myocardial cells in neonatal rats with hypoxic-ischemic encephalopathy

目的：探讨缺氧缺血性脑病（HIE）新生大鼠心肌Caspase-3、Cyt C蛋白的表达及其与心肌细胞凋亡的关系。方法：7日龄新生大鼠制备HIE经典模型。分为HIE组和假手术对照（NC）组,两组分别于HIE后1小时、4小时、12小时、24小时、48小时、72小时、7天取心脏组织,应用免疫组织化学法检测心肌组织Caspase-3、Cyt C蛋白的表达;应用TUNEL法检测心肌细胞凋亡。结果：HIE组24小时Caspase-3出现阳性细胞表达增多,48小时达高峰,24小时~7天Caspase-3的表达均明显高于NC组（P〈0.05）。HIE组24小时Cyt C出现较多的阳性细胞表达,72小时达高峰,至7天时仍高于NC组（P〈0.05）。HIE组12小时心肌阳性凋亡细胞开始增多,72小时达高峰,12~72小时各时间点阳性凋亡细胞明显高于NC组（P〈0.05）。Cas-pase-3、Cyt C蛋白表达与凋亡细胞数二者之间均呈直线正相关。结论：HIE新生大鼠心肌细胞Caspase-3、Cyt C蛋白表达增加,提示Caspase-3、Cyt C蛋白表达对心肌细胞凋亡起促进作用。

Objective：To explore the expression of Caspase-3 and Cyt C in myocardium of neonatal rats with hypoxic-ischemic encephalopathy（HIE） as well as the relationship with apoptosis in myocardium.Methods：All Seven-day-old SD rats in the study were randomly divided into HIE group and control group.At time of 1 h,4 h,12 h,24 h,48 h,72 h,7 d after HIE,heart tissues were obtained.Caspase3 and Cyt C protein expression were observed by immunohistochemistry.Cardiomyocyte apoptosis were observed by deoxyuridine triphosphate-biotin nick end labeling（TUNEL）.Results：At the time of the expression of Caspase-3 in heart tissue of neonate rats 24 h,was more positive cells appeared in HIE groups and the peak reached at the time of 48 h（P0.05）.The concentration appeared to be a slow descent.At the time of 7 d,there was higher concentration than that of normal control groups.At the time of 24 h,the expression of Cyt C more positive cells appeared in HIE groups and the peak arrived at the time of 72 h.After 12 hours apoptosis cells began increasing in HIE group,at 72 hours it reach the peak.Apoptosis cells in HIE group were higher than NC group at the time of 12 h to 72 h（P0.05）.Accompanied with the multiplication of Caspase-3 and Cyt C,apoptosis cells appeared more the expressions of Caspase-3 and Cyt C,had the positive correlation with cell apoptosis numbers.Conclusion：The expressions of caspase-3 and Cyt C in heart tissue of neonate rats increased in HIE groups.The expressions of Caspase-3 and Cyt C had the positive correlation with cell apoptosis numbers in HIE groups.It is indicated that Caspase-3 and Cyt C play an important role in apoptosis of cardiomyocyte in neonatal rats of HIE.