CARDIOVASCULAR EFFECTS PRODUCED BY MICROINJECTION of ANGIOTENSIN-(1-7) ON VASOPRESSOR and VASODEPRESSOR SITES of the VENTROLATERAL MEDULLA

Abstract

In this study, we determined the cardiovascular effects produced by micro-injection of the heptapeptide Angiotensin-(1-7) [Ang-(1-7)] into the rat ventrolateral medulla (VLM). Micro-injection of Ang-(1-7) into the rostral VLM and the caudal pressor area of the VLM produced significant increases in arterial pressure, comparable to that observed with micro-injection of Ang II. the changes in arterial pressure were associated with more variable changes in heart rate (HR) (usually tachycardia). On the other hand, micro-injection of Ang-(1-7) into the caudal depressor area induced decreases in arterial pressure and HR. the results suggest that, besides Ang II, Ang-(1-7) is involved in the mediation of the cardiovascular actions of the renin-angiotensin system in the VLM.