The adrenal cortex in restraint hypothermia and in adaptation to the stress of restraint.

Abstract

SUMMARY The role of the adrenal cortex in restraint-induced hypothermia and in adaptation to the stress of restraint was investigated. There was an increase in ascorbic acid and a less marked increase in the cholesterol content of the adrenals accompanying 1 week's exposure to the stress of light restraint to produce adaptation, as well as a decrease in the adrenal ascorbic acid and cholesterol levels accompanying restraintinduced hypothermia, but changes in adrenocortical activity were probably not of sufficient magnitude to account for either the increased thermostability after the adaptive procedure or the thermolability of the animals exposed to the short-term stress. It was also demonstrated that after a 7-day exposure to light restraint (to produce adaptation), adrenalectomized animals, maintained with isotonic salt solution or DCA, could not maintain a normal body temperature when restrained in the cold. Cortisone, whether administered alone or with DCA, permitted these adrenalectomized, adapted animals to maintain essentially normal body temperatures when exposed to restraint in the cold, indicating that adaptation had occurred.