Different effects of vasopressin and angiotensin II on baroreflexes.
Our data indicate that vasopressin facilitates baroreflex inhibition of lumbar sympathetic nerve activity by two mechanisms: it sensitizes baroreceptors locally and shifts the stimulus-response curve so that a lower carotid sinus pressure results in a certain level of reflex sympathetic inhibition; it also produces a corresponding shift when given i.v. and excluded from baroreceptors implicating a second, central mechanism for facilitation of baroreflexes. In contrast, angiotensin II attenuates baroreflex inhibition of peripheral sympathetic function and this is accounted for totally by a central action. Why these differences occur present challenging new questions for future investigation.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002339:Carotid Arteries / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects*; D011817:Rabbits; D012018:Reflex / Q000187:drug effects*; D013564:Sympathetic Nervous System / Q000502:physiology; D014667:Vasopressins / Q000494:pharmacology*
D014667:Vasopressins; D000804:Angiotensin II; D010656:Phenylephrine