Cardiovascular effects produced by micro-injection 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 heptapeptided 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.