Effect of ACTH on Incorporation of Labeled-Histidine Into Tissue Proteins in Male Adult Mice

Abstract

Injns. of radioactive histidine were given to 2 groups of mice for periods of time ranging from 20 min. to 9 days. One group was being treated simultaneously with ACTH. Greater radioactivity was found in expired CO2 in ACTH-treated animals than in normal controls. The ACTH-treated animals also showed greater radioactivity in the proteins of viscera and striated muscle. In general, the radioactivity of the non-protein filtrates of visceral tissue of animals treated with ACTH was higher than the non-protein filtrates of normal untreated animals. Another group of animals was subjected to subcut. injn. with labeled-histidine on alternate days within a 10-day period. At the end of this time, labeled-histidine injns. were terminated and half of the animals were treated with ACTH daily while the other half were left untreated. Animals were sacrificed at intervals of 7 days for a period of 28 days. The rate of release of radioactivity from the proteins of viscera and striated muscle is apparently the same for treated and untreated animals.