[Effect of lysosomal enzymes on myocardial electrical and contractile activity in burn shock].

Marked depression of the amplitude of isometric contractions of myocardial preparations, which was induced by lysosomal enzymes from the liver of control animals, was demonstrated in isolated rabbit papillary muscles. The decrease of contractility was not accompanied by remarkable changes in the amplitude or in the duration of intracellular action potentials. The negative inotropic action of lysosomal enzymes was similar to that of blood plasma of the burnt animals. Based on the appearance and subsequent activation of lysosomal enzymes in blood of the animals by the 20th to 60th min after thermal injury it is suggested that lysosomal enzymes might be one of factors that depress myocardial contractility in burn shock.