ABSTRACT
AIM:To investigate the effects of eplerenone (Epl) on thyroid hormone (T3) induced myocardial electrical remodeling .METHODS:The ventricles of 1~3 d neonatal rats were digested with 0.125%trypsin and 0.08%collagenase type 2.The cell suspension was replated for 90 min to reduce the proportion of non-myocardial cells.The isola-ted cardiomyocytes were randomly divided into control group , T3 group, Epl group and T3+Epl group.The cardiomyocytes were identified by immunofluorescence staining .The viability of the cardiomyocytes was measured by CCK-8 assay.The ex-pression of Kv1.5, Kv4.3, Cav1.2, connexin 40 (Cx40) and Cx43 at mRNA and protein levels was determined by immu-nofluorescence staining , real-time PCR and Western blot .RESULTS:The results of the cell immunofluorescence labeling conformed that the cultured cells were cardiomyocytes with more than 95%positive staining of sarcomeric α-actinin.Com-pared with control group , the mRNA and protein levels of Kv1.5, Kv4.3, Cav1.2 and Cx40 were increased, but the ex-pression of Cx43 was decreased in T3 group.The mRNA and protein levels of Kv1.5, Kv4.3, Cav1.2 and Cx40 were de-creased, but the expression of Cx43 was increased in Eplerenone group .Compared with T3 group, the mRNA and protein expression levels of Kv1.5, Kv4.3, Cav1.2 and Cx40 were decreased, but the expression of Cx43 was increased in T3+Epl group.CONCLUSION:Eplerenone partly reverses T3-induced myocardial electrical remodeling .