ABSTRACT
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.
