Effects of 17beta--estradiol on hypertrophy in cultured neonatal rat cardiomyocytes

Objective To observe effects of 17β-estradiol on phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes and to explore its mechanisms. Methods Using cultured neonatal rat cardiomyocytes treated with different factors as a model,surface area of cardiomyocytes was measured by computer photograph analysis software;the protein synthesis rate was assayed with leucine intake method;the proto-oncogene c-fos protein expression was assessed with immunocytochemistry technique;the markers of cardiomyocyte hypertrophy,embryonic genes such as β-MHC\,α-skA and ANP mRNA expressions were assessed with semiquantitative reverse transcription-PCR. Results 17β-estradiol inhibited obviously phenylephrine-induced increase of surface area and the protein synthesis rate of cardiomyocytes,reduced c-fos protein expression of hypertrophic cardiomyocytes,and down-regulated β-MHC、α-skA mRNA expressions and up-regulated ANP mRNA expression.Conclusion 17β-estradiol inhibits hypertrophy of cardiomyocytes and its mechanisms might be related with the suppression of c-fos protein expression,the reversion of the embryonic switching of contractile protein genes(βMHC and α-skA),the increase of ANP mRNA expression.