AimTo investigate the effects of hypoxia on the expression of Cx43 and apoptosis in hypertrophic rat cardiomyocytes.MethodsCardiomyocytes from newly born rats were cultured after digested in trypsin. The apoptosis rate of cardiomyocytes induced by hypoxia was evaluated by a modified Hoechst33258 fluorescent staining method.The expression of the Cx43 protein were detected by Western blot and fluorescent staining method.ResultsCompared with the control group, the apoptosis rate of hypertrophic cardiomyocytes induced by 24 h hypoxia was increased (15.42%±1.62%vs 2.56%±0.48%).The expression of Cx43 protein of hypertrophic cardiomyocytes was obviously decreased in comparison with the control group.Hypoxia could significantly down-regulate the Cx43 expression in hypertrophic cardiomyocytes than that of the normal cardiomyocytes (p<0.01). ConclusionsHypoxia can significantly increase the apoptosis rate and down-regulate the Cx43 expression in hypertrophic cardiomyocytes.These may be involved in the mechanisms of electrophysiology remodeling and malignant arrhythmia of hypertrophia myocardium induced by hypoxia.