[Dissociation between the development of myocardial contracture and heart damage in the "calcium paradox"].

The interrelationship between contracture development and heart damage during the calcium paradox under different sodium concentration in Ca-free media was studied on isolated rat hearts. It had been shown that calcium paradox development accompanied contracture development, intensive membrane disruption and alteration of tissue energy state. We had not found relation between contracture magnitude and degree of myocardial alterations in calcium paradox. Our dates confirm so-called intracellular hypothesis of calcium paradox. The experiments had shown close correlation between transmembrane sodium gradient in Ca-free media and degree of cellular damage and energy state alterations during calcium readmission in solution.