Effect of Resveratrol Preconditioning on Myocardial Dysfunction after Cardiac Arrest in Rats

Objective To investigate the protective effects and its potential mechanism of resveratrol preconditioning on rat cardiac arrest after return of spontaneous circulation (ROSC) with the study of hemodynamic parameters and nitrative stress in myocardium. Methods Cardiac arrest SPF SD rat model was established by transoesophageal cardiac alternating current stimulation. Intervention was implemented 15 min before cardiac arrest. Twenty four rats with ROSC after cardiac arrest were randomly assigned into five groups: vehicle, sham, resveratrol 2.3 mg/kg (A group), resveratrol 0.23 mg/kg (B group) and resveratrol 0.023 mg/kg (C group). Heart rate, mean arterial pressure, and left ventricular variables (+dp/dtmax and -dp/dtmin) were recorded in 0.5 h, 1.0 h, 2.0 h, 3.0 h, and 4.0 h respectively. Rats were sacrificed at 4 h after ROSC, and hearts were removed for determining expression of inducible nitric oxide synthase (iNOS) protein, myocardial peroxynitrite, and nitrotyrosine. Results Global ROSC rate was 72.7% after the induction of cardiac arrest. Resveratrol preconditioning did not improve ROSC rate significantly. Heart rate and blood pressure declined at early phase of ROSC, then heart rate recovered to the baseline value, but blood pressure still declined progressively. There were no significant differences between resveratrol groups and vehicle group. Myocardial function worsened progressively even after ROSC. Resveratrol improved cardiac function significantly，especially in lower concentration groups. Myocardial iNOS expression, peroxynitrite, and nitrotyrosine content increased significantly after ROSC. Resveratrol decreased these products significantly, and lower concentration groups did better. Conclusion Resveratrol preconditioning could improve cardiac dysfunction after ROSC, which may be associated with its inhibitory effect on nitrative stress.