Baroreflex buffering of pressor response to vasopressin is mediated by VI, not V2, receptors in conscious rats

McGrath. Baroreflex buffering of pressor response to vaso-pressin is mediated by V1, not V2, receptors in conscious rats. Am. J. Physiol. 264 (Regulatory Integrative Cornp. Physiol. 33): R345-R349, 1993.-Arginine vasopressin (AVP) enhances re-flex buffering of its own pressor response, thus attenuating its vasoconstrictor potential in vivo. To investigate the extent to which this effect of AVP is mediated by V1 or V2 receptors, mean arterial pressure (MAP) and heart rate (HR) changes were examined in response to graded injections of AVP or [Phe2,0rn8]oxytocin, a potent, selective &-receptor agonist, in the absence and presence of infusion of [Va14,0-Ar$]VP, a selective &-receptor agonist. Responses were compared in in-tact and autonomically blocked conscious rats. During auto-nomic blockade with methscopolamine and hexamethonium, the pressor sensitivities to AVP and [Phe2,0rn8]oxytocin wer