Seasonal metabolic changes in the frog, Rana pipiens.

Abstract

A study of seasonal changes in metabolic activity ,2 energy reserves in the frog, Rana pipiens, was conducted. Values for oxygen consumption, and carbon dioxide production were collected and used to indicate changes in the metabolism of the frogs' energy reserves. In contrast to the results of other investigators, respiratory quotients indicating a change to carbohydrate metabolism for winter and spring animals were never obtained in this study. One of the purposes of this study was to investigate the possibility pentose shunt activity during carbohydrate metabolism. Animals were injected with glucose-l-C1and glucose-6-c1to test for pentase shunt activity in February, April, May and June. An increase in pentose shunt activity was found only during the month of April. It was concluded that the increased ventose shunt activity was probably caused by a combination of fasting and the onset of the reproductive activity of the animals during March and April. The failure to obtain values indicative of carbohydrate metabolism for 02 consumption, CO 2 production, and R.Q. 's was possibly due to the maintenance of the animals within the laboratory, the juvenile age at which the animals were obtained, and because Tetracycline-HCl was used for the treatment of diseased frogs.