RATES OF DEVELOPMENT AND REGRESSION OF CHANGES DURING AND AFTER PROLONGED CORTISONE ADMINISTRATION IN RATS1

Abstract

Cortisone was given at a daily dose of 1-2 mg for 43 days to male rats weighing 150-200g. Body weight increase was depressed 2/3 by cortisone and had the following effects on organs: increases in liver, kidney and thyroid weights per 100 g of body weight; decreases in adrenal, lymph node and thymus weights on an absolute basis as well as per 100 g of body weight; increase in total N content of liver per 100 g of body weight; decreases in concentration of cholesterol and ascorbic acid per gram of adrenal gland and in the adrenal contents of these compounds per 100 g of body weight; decrease of thyroidal collection of I131. The serum concentration of ascorbic acid was elevated significantly by cortisone, but that of vit. A was not affected. Concentration of vitamin A in liver was not significantly altered in the cortisone-treated animals, but kidney vitamin A was markedly depressed. After cessation of cortisone both the treated and control groups were followed for an additional 120 days. The parameters discussed above reverted to the values of the control groups at varying rates, but most of them attained parity within 10-20 days after the end of the cortisone administration.