Resveratrol exerts anti-arrhythmic effects in rats with myocardial infarction through up-regulation of cardiac connexin43 expression

Abstract

Objective To investigate effect of resveratrol on ventricular arrhythmias in rats with myocardial infarction. Methods Twenty-four adult male Sprague-Dawley rats were randomly divided into myocardial infarction group(MI group, n=8), resveratrol group (Res group, n=8) after successful establishment of MI model, and sham group (n=8) which underwent thoracotomy and pericardiotomy without the left anterior descending ligation.Res group was given a dose of 10 mg·kg -1·d-1 resveratrol (i.g.once a day) for 4 weeks.MI group and sham group received 5% sodium carboxymethyl cellulose gavage.At 4 weeks after induced MI the programmed electrical stimulation was performed in vivo electrophysiological studies.Myocardial infarct size was detected by Masson's staining.The distribution of connexin43(Cx43) and P368Cx43 were detected by immunohistochemical staining methods.The Cx43, P368Cx43 and PKCβ2 expressions were measured using western blot. Results Compared with MI group, resveratrol significantly reduced the incidence rate of induced ventricular arrhythmias (87.5% vs. 37.5%, P<0.05), and the ventricular fibrillation threshold was significantly higher [(3.2±0.3)V vs.(5.2±0.8)V, P<0.05]. Compared with the sham group, the expression of Cx43 within the infracted myocardium was significantly lower (P<0.05), while the expressions of P368Cx43 and PKCβ2 were greatly higher (P<0.05). Cx43 levels increased in myocardial infarction rats which received resveratrol (P<0.05). Conclusion Resveratrol could effectively improve the cardiac electrophysiological properties in MI rats and increase myocardial expression of Cx43 protein, and could prevent the occurrence of ventricular arrhythmias. Key words: Myocardial infarction; Arrhythmias; Connexin43; Resveratrol