中文摘要：

为检测血管紧张素Ⅱ（angiotensinⅡ,AⅡ）对小鼠胚胎干细胞（embryonic stem cells,ESCs）向心肌细胞方向分化的作用,采用10-4mol/L维生素C诱导小鼠R1胚胎干细胞分化为心肌细胞.Western印记检测胚胎干细胞诱导分化的心肌细胞中表达血管紧张素Ⅱ1型受体（angiotensinⅡtype 1 receptor,AT1R）.诱导分化期间用1μmol/L AⅡ刺激胚胎干细胞,计数搏动拟胚体的比例;诱导分化第14 d用real-time RT-PCR和Western印记检测心肌标志物的表达确定其作用.结果显示,与对照组相比,1μmol/L AⅡ处理组可显著增加搏动拟胚体的比例,上调心肌标志物mRNA的表达.预先用1μmol/L洛沙坦处理1 h后可显著阻碍这种上调作用.本实验结果表明,AⅡ通过AT1R可促进小鼠R1胚胎干细胞向心肌细胞分化.

英文摘要：

To investigate the effect of angiotensin Ⅱ （A Ⅱ ） on the cardiac differentiation in embryonic stem cells （ESCs）, R1 mouse ES cells were induced by 10-4 mol/L vitamin C to differentiate into cardiomyocytes. Western blotting revealed that angiotensin type 1 receptor （AT1R） expressed in cardiomyocytes derived from mouse embryonic stem cells. By administering 1μmol/L AⅡ with or without 1μmol/L Losartan （ATIR antagonist） pretreatment, we demonstrated that AⅡ significantly enhanced cardiac differentiation as determined by increased percentage of beating embryoid bodies and a higher expression level of cardiac markers. On the contrary, A Ⅱ stimulated differentiation was inhibited by the presence of AT1R antagonist. These findings suggested that AⅡ promoted differentiation of cardiomyo- cytes from embryonic stem cells via AT1R.