The Study of AngiotensinIIInducing Apoptosis in Neonatal Rat Cardiomyocytes

Objective To explore the mechanism of angiotensinⅡinducing apoptosis in cultured cardiomyocytes of neonatal rat.Methods Cultured neonatal rat cardiomyocytes were divided into three groups.Cells in control group were incubated in medium without serum 2 h 6 h 12 h 24 h;Cells in AntⅡgroup were incubated with 10~7mol/lAngⅡ2 h,6 h,12 h,24 h.Cells in AngⅡand AngⅡtype 1 receptor antagonist group were incubated with 10~7mol/l AntⅡphs 10~5mol/l Irbesartan.The apoptosis cells were de- tected by TUNEL assay,caspase-9 mRNA was measured by RT-PCR.Results With the prolonging of stim- ulated time,a significant increase in expression of caspase-9 mRNA began as early as at 2 hours and reached a plateau at 6 hours and maintained at high level up to 24 hours.However,a significant decrease in expres- sion of caspase-9 mRNA in group of AngⅡplus Irbesartan was observed at same time point,and the positive rate of the apoptesis was increased significantly.Conclusion Angiotensin could induce apoptesis of neo- natal rat cardiomyocytes,which might be mediated by AⅡtype 1 receptor.Meanwhile it induces apoptosis of neonatal rat cardiomyocytes through caspase-9-dependent pathway.