Heart-Coronary Vessels and Cardiomyocytes

Abstract

The renin-angiotensin system (RAS) is crucial for cardiovascular homeostasis. Its relevance is highlighted by the undiscussed role of the anti-hypertensive drugs that modulate this system used in the medical practice. Nowadays, the Angiotensin(Ang)-(1-7) peptide is recognized as a biologically active component of this system. This heptapeptide is formed mainly through the action of the angiotensin-converting enzyme 2 (ACE2) using Ang II as substrate. This reveals an important metabolic pathways since, at the same time, ACE2 degrades the vasoconstrictor peptide Ang II and generates Ang-(1-7), a vasodilator product. Additionally, it is well-established that the G protein-coupled receptor Mas is a functional ligand site for Ang-(1-7). Also, it is now clear that the RAS is composed by two different axes: ACE/Ang II/AT1 receptor and ACE2/Ang-(1-7)/Mas. Functionally, the ACE2/Ang-(1-7)/Mas arm is an endogenous counter-regulatory pathway within the RAS whose actions are opposite to the vasoconstrictor/proliferative axis of the RAS formed by ACE/Ang II/AT1 receptor. In this chapter, we will briefly discuss the main findings concerning the biological role of Ang-(1-7) and its receptor Mas focusing on coronary vessels and cardiomyocytes.