[Aminoacyl-tRNA-synthetases and their high molecular weight complexes in experimental myocardial ischemia]. / Aminoatsil-tRNK-sintetazy i ikh vysokomolekuliarnye kompleksy pri éksperimental'noi ishemii miokarda.

A number of aminoacyl-tRNA synthetases from rabbit liver during experimental myocardial infarction and from pig myocardium upon 15-min of autolysis were found to increase their activity in aminoacylation. Direct correlations between the activities of high molecular weight complexes and of the total extracts were not observed. It was shown that the specific activity of endogenous inorganic pyrophosphatase increased markedly during the ischemia of myocardium both in total myocardium extracts and in high molecular weight complexes.

[tRNA and aminoacyl-tRNA synthetases from the liver of rabbits in experimental myocardial infarction]. / tRNK i aminoatsil-tRNK sintetazy pecheni krolikov pri éksperimental'nom infarkte miokarda.

An acceptor activity of tRNA for glycine, glutamic acid, leucine, serine and phenylalanine was decreased in rabbit liver tissue within 6, 12 and 24 hrs after myocardial infarction; the activity was reduced within 72 hrs. Heating of tRNA under conditions of transition of biologically inactive conformations into active forms led to reduction of the acceptor activity. Contrary to tRNAs a pronounced activation of glycyl-, glutamyl-, leucyl- and phenylalanyl-tRNA synthetases was observed in liver extracts within 6, 12, 24 and 72 hrs after myocardial infarction. A correlation between the activation of these enzymes and alterations in their activity after association with high molecular complexes was found only for several aminoacyl-tRNA synthetases studied. The rate of tRNA aminoacylation specific for alanine, and alanyl-tRNA synthetase activity were unaltered within all the periods of myocardial infarction.