Effect of Hypothalamic Lesions on Pituitary-Adrenocortical Responses to Histamine and Methopyrapone

Abstract

A study to determine the effect of destructive hypothalamic lesions on pituitaryadrenocortical responses following the administration of histamine and methopyrapone (metyrapone) has been carried out in dogs. Adrenocortical responses were evaluated by an increase in the secretory rate of 17-OHCS in adrenal venous blood collected by the retention cannula method. The responses to histamine and to methopyrapone were both suppressed by anterior hypothalamic lesions. In dogs with posterior hypothalamic lesions, the response to histamine was normal, while that to methopyrapone was suppressed. On the basis of these findings, a functional dichotomy of the hypothalamus concerning the regulatory mechanism of ACTH secretion is proposed. (Endocrinology81: 941, 1967)