Cardiovascular Responses to Intrathecal Vasopressin in Conscious and Anesthesized Rats.

摘要

Increases in mean arterial pressure and heart rate have been documented after the intrathecal administration of vasopressin (AVP) in rats. Prior studies on our laboratories with conscious rats indicated that these cardiovascular changes were associated with a marked hindlimb sensorimotor dysfunction. In this study, which represents the first systematic comparison of the effects of intrathecal AVP in conscious and anethesized rats, we demonstrate that in conscious male Sprague-Dawley rats 1) the motor dysfunction induced by intrathecal AVP is accompanied by a rise in mean arterial pressure that is significantly greater than that produced by an equal intravenous does of AVP, and 2) both paralytic and pressor effects of intrathecal but not intravenous AVP are blocked by the intrathecal administration of the V 1-receptor antagonist but are not blocked by intravenous phenoxybenzamine, hexamethonium, or angiotensin II, an angiotensin II antagonist. Keywords: Paralysis; Cardiovascular changes; Spinal cord injury; Anesthesia; V-antagonist; Sprague-Dawley rat, Reprints.