EFFECT OF INTERRENALS ON CARBOHYDRATE METABOLISM OF AMPHIBIA

1. The blood sugar level and the content of glycogen in liver and muscle of the common frog Rana temporatia L. show seasonal changes (Figs. 1-3). 2. Maximal values of blood sugar can be found in February/March and September. Liver and muscle glycogen decrease from January to the year until they decline to an amount which is only 20-30% of that present at the end of the year. 3. Hypophysectomy primarily lowers the blood sugar level and the glycogen content of the muscle. But liver glycogen sometimes increases after hypophysectomy especially from April to August. 4. ACTH and the corticosteroids aldosterone, corticosterone and cortisol elevate blood sugar in normal and hypophysectomized frogs (Figs. 4, 5). Liver and muscle glycogen are changed differently during the year. Corticosteroids induce elevation most markedly in November and December. 5. The threshold dosage of ACTH was determined to be 0.001 I. U., that of corticosteroids 0.01 γ per frog (body weight about 25 g). The threshold dosage might be dependent on the season (Figs. 6-8). 6. Multiple hormone injections (4 injektions on 4 subsequent days) are necessary to demonstrate the described reactions. Single injektions cause distinct, but often not significant, changes (Figs. 9, 10). © 1969 Springer-Verlag.