Abstract: | It was found, that adaptation of rats to cold and physical exercise prevented ventricular fibrillation, caused by the occlusion of the left anterior coronary artery. An adaptation to cold only or to physical exercise do not prevent ventricular arrhythmias. An significant increase of prostacyclin/thromboxane index in plasma and heats was estimated in rats adapted to cold and physical exercise in relation to control non-adapted group in condition of functional rest or acute myocardial ischemia. It was assumed that an increase of prostacyclin/thromboxane ratio has a significant role in antiarrhythmic action of adaptation. |