[Various characteristics of protein-synthesizing apparatus of the myocardium during total ischemia].

A decrease in the rate of protein synthesis as well as an increase in the synthesis time of "medium-size" polypeptide chain were detected in total rabbit myocardium ischemia, which were evaluated using rabbit myocardium cell-free protein-synthesizing systems. The decrease in the synthesis rate of total myocardial proteins was shown to depend on the state of ribosomes function. Redistribution in the pools of membrane-bound and free ribosomes as well as a decrease of polyribosomes amount in total pool of myocardial ribosomes were observed under conditions of total myocardial ischemia.

[Study of the properties of leucyl-tRNA synthetase from porcine myocardium in a normal state and in experimental ischemia].

Catalytic properties and thermostability of leucyl-tRNA-synthetase were studied both in free form and in the form of high molecular complexes, isolated from pig myocardium under normal state and after 15 min and 30 min ischemia. Km values of free and associated forms of leucyl-tRNA-synthetase were similar either in normal state or after 15-30 min ischemia. Complex-formation protected the enzyme from thermic inactivation under normal and ischemic conditions.

[Distribution of aminoacyl-t-RNA-synthetase activity in rabbit liver cells during disruption of protein biosynthesis in experimental myocardia infarct].

Distribution of the aminoacyl-tRNA synthetase activity has been studied in the normal rabbit liver cells and in the model of protein synthesis damage, i.e. under experimental myocardial infarction (EMI).

[Biological activity of tRNA and aminoacyl-tRNA-synthetases from the swine myocardium in anoxia and subsequent reoxygenation].

Distinct decrease in the rate of aminoacylation of tRNAs, specific to alanine, glutamic acid, leucine and serine, was found after 20 min anoxia of perfused pig heart. In the anoxia activity of aminoacyl-tRNA synthetases of the same amino acid specificity was increased. Reduction of these macromolecules activity was observed in reoxygenation of the anoxic myocardium.

[Aminoacyl-tRNA synthetases and their high molecular weight complexes in autolysis of the swine heart].

In pig myocardial extracts autolyzed within 15 min alanyl-, glycyl-, glutamyl-, leucyl- and seryl-tRNA synthetase activities were increased as compared with controls. The enzymatic activities were decreased after autolysis for 30 min. The 15 min autolysis was shown to decrease the molecular mass of the glycyl-tRNA synthetase complex.