不同β受体阻滞剂对钙调磷酸酶在心肌凋亡及腺病毒介导钙调磷酸酶Aα基因过表达的影响

摘要

Objective To explore the influence of different β - receptors inhibitors on the expression of calcineurin (CaN) and car-diomyocyte apoptosis induced by ischemia - reperfusion and isoproterenol. Methods A langendorff perfused rat myocardial damage model was established by ischemia - reperfusion and isoproterenol (Iso) to observe the rates of the cardiomyocyte apoptosis and the raRNA levels of CaN. And neonatal rat cardiomyocytes were cultured after AdCnAα infection and treated with isoproterenol and reox-ygenation after hypoxia. On the basis of myocardial damage, atenolol and carvedilol were added. The cardiomyocyte apoptosis was judged by TUNEL and DNA ladder. The rate of cardiomyocyte apoptosis was evaluated by flow cytometry and the mRNA levels of CaN were investigated by RT - PCR. Results Carvedilol decreased the mRNA level of CaN and the rates of cardiomyocyte apoptosis of the langendorff perfused rats myocardial damage model (P<0.05). Atenolol had trivial effect on CaN and apoptosis(P>0.05) in isolated rat heart models. In cultured neonatal rat cardiomyocytes models, both carvedilol and atenolol decreased apoptotic rates of cardiomyocytes compared with normal control cells (P<0.05), but the CaN mRNA levels had little change between groups (P>0.05). Conclusion Carvedilol could adjust the rates of cardiomyocyte apoptosis by adjusting the mRNA level of CaN.%目的 研究不同选择性的β-肾上腺素能受体阻滞剂对缺血再灌注(I/R)及异丙肾上腺素(Iso)致心肌凋亡时心肌细胞凋亡率的影响及其对钙调磷酸酶(CaN)的调节作用.方法 采用Langendorff大鼠离体心脏灌流技术制备I/R+Iso所致离体心脏损伤模型;体外培养乳鼠心肌细胞的方法制备腺病毒介导的CnAα(AdCnAα)过表达后,再H/R+Iso作用致心肌细胞损伤模型.在损伤模型基础上给予不同选择性的β-肾上腺素能受体阻滞剂(阿替洛尔、卡维地洛)进行干预,用TUNEL或DNA Ladder法确定心肌细胞凋亡,流式细胞术检测心肌细胞凋亡率,RT-PCR法检测CaN mRNA水平.结果 离体大鼠心脏心肌损伤模型,经卡维地洛干预后,心肌细胞凋亡率和CaN mRNA水平与阳性对照组比较均降低(P＜0.05);经阿替洛尔干预后,心肌细胞凋亡率和CaN mRNA水平与阳性对照组比较无统计学意义(P＞0.05).体外培养乳鼠心肌细胞法制备的感染CnAα重组腺病毒(AdCnAα)后心肌细胞损伤模型,经阿替洛尔和卡维地洛干预后,心肌细胞凋亡率与阳性对照组比较均降低,差异有统计学意义(P＜0.05),且卡维地洛使心肌细胞凋亡率下降更为明显;CaN mRNA表达水平与阳性对照组比较差异无统计学意义(P＞0.05).结论 非选择性(α1、β)肾上腺素能受体阻滞剂卡维地洛可通过调节CaN的表达来调节I/R+Iso作用所致心肌细胞凋亡率的变化,选择性β1肾上腺素能受体阻滞剂阿替洛尔对于心肌细胞凋亡及CaN mRNA表达水平的影响有待于进一步研究.