Nitrogen Balance, Liver Protein Repletion and Body Composition of Cortisone Treated Rats

In 1940, Long, Katzin and Fry demonstrated that the administration of adrenal cortical extract to fasting rats caused a loss of nitrogen in the urine and an increase in liver glycogen. They suggested a relationship between protein breakdown and glycogen synthesis in such animals. For reviews of subsequent investigations, the reader is referred to those of Ingle (1950), Sayers (1950) and Engel (1951). When cortisone acetate1 became available in 1949, it seemed desirable to investigate further the effects of cortisone on nitrogen balance, on liver protein regeneration, and on the distribution of protein and fat in the body. EXPERIMENTS AND RESULTS Male albino rats of the Carworth strain were selected from single shipments and grouped to obtain equivalent average body weights. Adrenalectomies were performed by the lumbar approach under nembutal anesthesia and operated rats were given 1% saline to drink. All animals were housed in individual mesh-bottom cages in air conditioned quarters during the experiments.