STUDIES ON EFFECT OF CORTISONE ON RAT LIVER TRANSFER RIBONUCLEIC ACID

The effect of cortisone on the population of rat liver transfer ribonucleic acid and aminoacyl transfer ribonucleic acid synthetases was studied. The 20-30 % increase in labeling of transfer ribonucleic acid, following cortisone administration, seemed to represent a general increase in most or all types of rat liver transfer ribonucleic acid, rather than a preferential increase in the synthesis of a few transfer ribonucleic acids. No gross differences in relative abundance of amino acid specific transfer ribonucleic acids were apparent in assays of amino acid acceptance capacities of transfer ribonucleic acid obtained from control and cortisone-injected rats. Cortisone did not produce detectable changes in the activities of liver aminoacyl transfer ribonucleic acid synthetases, nor did the hormone form a stable complex with liver transfer ribonucleic acid in vitro or in vivo. In addition, no changes were found in the isoaccepting species of leucine transfer ribonucleic acid or tyrosine transfer ribonucleic acid, after cortisone administration. © 1969, American Chemical Society. All rights reserved.