The effect of hypothalamic lesions and hypophysectomy on adrenal weight in Sceloporus cyanogenys

Abstract

Adrenal hypertrophy was induced in male Sceloporus cyanogenys with Metyrapone. Radiofrequency lesions of the anteromedial hypothalamus and of the median eminence were followed by a decrease in the weights of the adrenal glands compared to those of the control animals, and hypertrophy of the glands did not occur following metyrapone. Both sham-operation and lesions of other areas of the brain (cerebral hemisphere, posterior and lateral hypothalamus) increased adrenal weight; however, the weight increase induced by sham-operation was less than that induced by lesions of these areas of the brain. While Metyrapone increased adrenal weight in all groups other than those with lesions of the anteromedial hypothalamus and median eminence, the increase over and above that caused by the lesions of other areas of the brain was not statistically significant. Lesions of the hypothalamus, wherever placed, increased thyroid weight whereas lesions of the cerebral hemispheres did not. Hypophysectomy prevented the adrenal weight response to Metyrapone, and the injection of ACTH increased adrenal weight in both intact and hypophysectomized animals.