Effect of a vasopressin antagonist d(CH2)5Tyr(Met)AVP on the development of renal vasospasm induced by estrin plus vasopressin administration in rats.

The authors studied rats pretreated with estrin acetate to determine the renal circulation changes caused by vasopressin and how these changes are influenced by the pressor effect of an antagonist of vasopressin d(CH2)5Tyr(MET)AVP. Abdominal angiography was performed with contrast material administered via a catheter introduced through the common carotid artery up to the aortic arch. After vasopressin administration, a marked spasm occurred in the larger renal arteries, the arteriovenous time increased, and the parenchymal filling became defective. Renal circulation remained undisturbed if the vasopressin antagonist was administered simultaneously. The results suggest that the vasopressin antagonist prevents renal vasospasm after vasopressin administration in rats pretreated with estrin.