Endocrine function in dogs after ablation of the area postrema.

Abstract

Possible neuroendocrine functions of the area postrema have been investigated by studying adrenal cortical, adrenal medullary, thyroid and gonadal function and carbohydrate metabolism in 13 dogs in which this region was surgically ablated. Normal unoperated animals and five dogs in which the area had sustained only minor damage served as controls. Adrenal cortical function, as measured by the output of 17-hydroxycorticoids in the adrenal vein and by adrenal weight and histological findings, was normal. Also normal were thyroid function (uptake of radioactive iodine, thyroid weight and histological findings) and testicular morphology. Secretion of catechol amines from the adrenal medulla after surgical trauma was not affected by the lesions. The fall in blood pressure following hemorrhage was slightly greater in the animals with lesions, but epinephrine and nor-epinephrine secretion in response to this stimulus were not abnormal.