| Abstract: | An antiarrhythmic action of water-soluble antioxidant SD-6 from 3-hydroxypyridine class and its effect on the transmembrane potentials were studied using the isolated rat heart and papillary muscle. Ischemia was induced by the occlusion of the left anterior descending coronary artery. 10 minutes later the ligation was removed and reperfusion was achieved. In the control, ischemia induced premature ventricular complexes, tachycardia and, in some cases, fibrillation. During perfusion total fibrillation occurred in 100% of the experiments. SD-6 in the doses of 10(-6) g/ml and 5 X 10(-6) g/ml significantly reduced the incidence of fibrillation and tachycardia. In the experiments on the papillary muscle SD-6 during reperfusion completely normalized the action potential duration and removed depolarization developed in hypoxia, which suggests the ability of the antioxidant to block reperfusion-induced arrhythmias by normalization of the parameters of electrical heterogeneity. These data show that the origin of reperfusion-induced arrhythmias is connected with the activation of free radical metabolites and that their scavengers--synthetic antioxidants from 3-hydroxypyridine class--can be used as new antiarrhythmic agents. |
