EFFECT OF ESTROGEN ON NOREPINEPHRINE-INDUCED APOPTOSIS IN CULTURED NEONATAL RAT CARDIOMYOCYTES / 解剖学报

ABSTRACT

Objective To study the effect of 17?-estradial(E-2) on apoptosis of cardiomyocytes induced by norepinephrine(NE) in vitro and its mechanism. Methods The cultured neonatal rat cardiomyocytes were treated with NE(50??mol/L),E-2(10?nmol/L) or NE(50??mol/L)+E-2(10?nmol/L) respectively in serum-free DMEM for 48?h.The morphological changes of myocytes were studied by phase-microscopy and transmission electron microscopy;apoptosis was identified by DNA laddering and apoptotic rate was assayed by flow cytometer;cfos protein in cardiomyocytes was detected using semiquantitative immunofluorescence cytochemistry technique. Results 17?-estradiol inhibited the morphological changes of apoptotic cardiomyocytes induced by norepinephine such as cell atrophy,condensed chromatin clumps against the nuclear envelope associated with swelling of mitochondria and presentation of apoptotic body,DNA laddering disappeared,the apoptotic rate decreased and the expression of c-fos protein inhibited in cardiomyocytes.Conclusion 17?-estradiol can protect cultured cardiomyocytes from apoptosis induced by norepinephrine,its mechanism might associate with suppression of c-fos protein expression.