Vasopressin receptor subtypes in dorsal hindbrain and renal medulla

We have investigated the ability of a series of synthetic vasopressin analogues and related peptides to compete with (³H)-arginine⁸ vasopressin for binding sites in rat renal medulla and dorsal hindbrain. In renal medulla, arginine⁸ vasopressin and deamino arginine⁸ vasopressin, a selective antidiuretic, were equipotent while two antagonists of the pressor action of arginine vasopressin were less potent. In the dorsal hindbrain, arginine⁸ vasopressin and the pressor antagonists were more potent than the synthetic antidiuretic. Potency profiles of these and other analogues suggest that the renal medulla and dorsal hindbrain vasopressin receptors represent different subtypes.