Effect of Removal of Various Parts of the Brain on ACTH Secretion in Dogs.

Abstract

The adrenocortical response to the trauma of cannulating the adrenal vein has been tested in dogs 4 hours after removal of various parts of the brain. Compared to controls, 17-hydroxycorticoid output in adrenal venous blood is slightly decreased in dogs in which all brain tissue above the pons except the hypothalamus has been removed. Output was significantly lower, but still definitely above basal levels in dogs in which the entire brain above the pons had been removed. It was in the same range when the entire brain had been removed. Acute section of the pituitary stalk decreased the adrenocortical response to an approximately equal degree. Removal of the pituitary as well as the brain reduced output to low levels. These data do not support the hypothesis that the hindbrain secretes a factor which stimulates the pituitary to secrete ACTH.