Suprarenal Cortex and Temperature Regulation

Abstract

The presence of the suprarenal cortex is necessary for proper temperature regulation in the rat. Wyman and turn Suden 1 found that suprarenalectomized rats having gross masses of cortical tissue, transplanted or accessory, maintained their body temperature as well as normal rats during 2 hours in a moderately cold room (40° to 500 F), but that rats having cortical insufficiency suffered a decline in body temperature and did not recover their original temperatures in a warm room so soon as those having cortical tissue. It was suggested that a disturbance in physical heat regulation, i. e., increased heat loss, as well as metabolic disturbance might account for this disability. Hartman, Brownell and Crosby 2 found that the administration of cortin enabled suprarenalectomized rats to produce heat and maintain their temperature in a cold environment almost as well as normals, and suggested that inadequate heat production is responsible for the disability of suprarenalectomized animals.

The importance of the sympathico-adrenal system in temperature regulation is well known. Cannon, Querido, Britton and Bright 3 concluded that excitation of the suprarenal medulla constitutes a primary line of defense when there is a disturbing heat loss, the extra output of adrenin increasing heat production, while a secondary line of defense would be increased muscular activity, i. e., shivering. Hartman, Brownell and Crosby 2 pointed out that shivering is a weak reaction in the rat as compared with other animals, and suggested that the reduction in voluntary muscular activity seen in suprarenalectomized rats, especially in a cold environment, might in part explain their inability to maintain their temperature when threatened with heat loss. The suprarenal cortex, therefore, would be an important part of the secondary line of defense.