[Effect of caffeine on various regulatory mechanisms, rhythmogenesis and contractile function of the isolated rat heart in ischemia and post-ischemic reperfusion].

The rat hearts isolated and perfused by the Langendorf method were used to examine the effects of caffeine-induced increase in cAMP levels on the contractility, rhythmogenesis, some mechanisms of myocardial autonomic regulation in ischemia and resultant reperfusion. The caffeine-induced elevated intracellular cAMP resulted in normalization of myocardial contractility in reperfusion, as well as in stabilization of norepinephrine levels and cardiac adrenoreactivity during ischemia and reperfusion. The positive action of higher cardiomyocyte cAMP levels on the performance of the heart and its sympathetic and parasympathetic control was followed by a reduction in myocardial sensitivity to the induced lipid peroxidation. The paper discusses that cAMP plays a significant role in the formation of adaptive responses of the heart in its ischemia and in reperfusion.