Abstract
Adrenocortical activity of rats kept at a high ambient temperature of 32°C. for approximately 3 weeks was studied.
1. Adrenal weight, adrenal contents of cholesterol, ascorbic acid and corticosterone in rats kept at 32°C. did not depart from the values obtained in those kept at 20°C. Corticosterone content in the blood plasma of rats at 32°C. was slightly less than that in rats at 20°C., but the difference was not statistically significant.
2. In both groups of rats adrenal ascorbic acid concentration decreased to similar extent after administrations of epinephrine or ACTH.
3. The increase in corticosterone content in the adrenal and blood plasma provoked by epinephrine or ACTH injections was significantly greater in rats at 20°C. than in those at 32°C.
4. The reduced adrenal response to exogenous ACTH in rats kept at 32°C. was also demonstrated in hypophysectomized rats.
