Abstract
Summary
Injections of either MJ 9465-2 or ADH, iv, depressed and increased, respectively, urine volume excretion and osmolality in dogs undergoing water diuresis. In contrast, only transient changes in urine flow and osmolality were observed in animals hydrated with saline and excreting an iso-or hypertonic urine. As demonstrated by ia administration, MJ 9465-2 (80 μg/kg) is devoid of any direct ADH-like activity. The antidiuretic response elicited by MJ 9465-2 was independent of the anesthetic agent administered. Ganglionic blockade, which abolished the acute pressor and positive chronotropic responses elicited by MJ 9465-2, had no effect on either the delayed pressor component or the induced antidiuretic activity. The data suggest that iv injection of MJ 9465-2 causes the release of a vasoactive, antidiuretic material, probably vasopressin.
The authors are grateful to Mr. R. Snyder and Mr. J. Preston for their excellent technical assistance.
Get full access to this article
View all access options for this article.