The Changes of Survival Rate of Cardiomyocytes Influenced by Overexpressing β_2-adrenoceptors and its Mechanisms in Rat

Objective To investigate the protective effects of overexpression of β2-adrenoceptors on adult rat cardiomyocytes stimulated by different concentrations of isoproterenol(ISO) and its mechanisms.MethodsIndividual cells were isolated and cultured from adult rats.Cultured cardiomyocytes were randomly divided into a normal group and two groups which were infected with adenoviruses containing the sequence of EGFP and human β2-adrenoceptor-EGFP.Cultured for 48 h,observed the survival rates of the cardiomyocytes which were stimulated by different concentrations(10-6 mol/L,10-5 mol/L,10-4 mol/L)of isoproterenol(ISO) pre and after 2 h,β2-AR expression was detected by Western blot.ResultsWestern blot indicated that the group which transfected the Adv.with β2-AR gene β2-AR protein expression was obviously higher than the other two groups(P0.05).There was no obviously difference in the correction value of the two groups stimulated by ISO of 10-6 mol/L and 10-5 mol/L,when stimulated by 10-4 mol/L ISO β2-adrenoceptors of transfected group was obviously higher than the other two groups(P0.05).ConclusionOverexpression of β2-adrenoceptors protect cultured adult rat cardiomyocytes from the high concentration(10-4 mol/L) of ISO,the mechanisms may be that β2-AR coupled to Gi Protein.