Angiotensin-(1-7) in hypertension

Recent evidence suggests that angiotensin-(1-7) is a bioactive component of the renin-angiotensin system that may oppose or, in certain situations contribute to the actions of Ang II. Ang-(1-7) can be directly formed from Ang I bypassing the requisite production of Ang II. In contrast to forming Ang II, angiotensin-converting enzyme hydrolyses Ang-(1-7) to inactive fragments. Angiotensin-converting enzyme inhibitors substantially augment circulating levels of Ang-(1-7) and increase the peptide's half-life six-fold. Thus, angiotensin-converting enzyme may constitute an important regulatory point to balance the actions of Ang II, Ang-(1-7) and bradykinin. Indeed, Ang-(1-7) can potentiate the actions of bradykinin through a receptor-mediated site and a direct interaction with angiotensin-converting enzyme. We summarize recent studies that reveal depressor, vasodilator, and antihypertensive actions of Ang-(1-7) thus providing evidence that Ang-(1-7) is the antihypertensive peptide of the renin-angiotensin system.