Antidiuretic response to electrical stimulation in brain stem of the monkey

¹ Departments of Anatomy, Medicine, and Pediatrics, University of Rochester School of Medicine, Rochester, New York

Antidiuretic hormone release was produced in conscious monkeys by electrical excitation of certain regions in the brain stem. The experimental design allowed repeated control and test observations in the same animal over a period of months. Alterations in free water clearance and urine osmolality resulted from electrical stimulation of the hypothalamus, the mesencephalic reticular formation, the ventral tegmental area of Tsai, and the periaqueductal gray substance. A similar drop in free water clearance and a rise in urine osmolality without a change in glomerular filtration rate was observed in the same animals after intravenous infusion of vasopressin. No significant changes in free water clearance or in urine osmolality were observed during the taking of blood samples, the infusion of isotonic saline or of 5% dextrose, or as a result of stimulation of the dorsolateral hypothalamus, thalamus, red nucleus, tectum, pons, and the optic chiasm.

Key Words: antidiuretic hormone • electrical stimulation of brain • hypothalamus • mesencephalon • neuroendocrinology • neurohypophysis • pituitary • renal clearance • reticular formation • vasopressin

Submitted on March 14, 1963