A COMPARISON OF FREE ADRENAL CORTICAL STEROIDS IN THE BLOOD OF A HIBERNATING AND NON-HIBERNATING MAMMAL

Abstract

White rats and hamsters were fasted and exposed to cold (6 ± 1 °C) for various periods of time. The adrenal glands were weighed and adrenal cortical steroids were extracted from the blood for separation by paper chromatography.The adrenal weight was not a reliable index of adrenal cortical activity as measured by the quantities of circulating hormones. Two steroid fractions were separated from rat and hamster blood. The fast component was identified as corticosterone and the slow component as an amorphous fraction.The adrenal cortical response to cold is different in rats and hamsters. The hamster does not have the typical alarm reaction and only trace quantities of hormones are found in the hibernating animal. Within 6 hours of arousal the concentrations of circulating adrenal cortical hormones have increased to or beyond those of the control animals. The changes in circulating adrenal cortical hormones of hamsters exposed to cold for varying periods of time can be correlated with changes in their intermediary metabolism and ion balance.