[Phenomenon of adaptive stabilization of cardiac structures and their protection]

Animal adaptation to repeated non-damaging stresses was shown to lead to the development of a phenomenon of adaptive stabilization of cardiac cellular structures. In isolated hearts, it appeared as a multifold decrease in reperfusion-induced arrhythmia severity, a sharply limited release of enzymes during the reperfusion paradox, and a lack or reduction in the contracture due to high calcium concentrations. The sarcoplasmic reticulum and mitochondria isolated from these hearts were found to be much more resistant to autolysis than the controls and to retain their function during prolonged storage. After coronary ligation in the adapted animals, the zone of acute ischemia was identical to that in the controls, and the necrotic zone measured 2 days later was reduced by more than 40%. Thus, the phenomenon of adaptive stabilization of cellular structures possesses no anti-ischemic effect, but forms the basis for a strong cytoprotective effect, thus providing protection of the heart from the necrotic action of ischemia. The author also discusses whether the genetic mechanism may be responsible for the phenomenon of adaptive stabilization of the structures and stress proteins may make a contribution to the phenomenon.