%0 Journal Article
%T Beyond the circulating renin angiotensin aldosterone system
%A Walmor De Mello
%J Frontiers in Endocrinology
%D 2014
%I Frontiers Media
%R 10.3389/fendo.2014.00104
%X The activation of the classical renin angiotensin aldosterone system (RAAS) is known to be involved in the regulation of blood volume and blood pressure and plays an important role in cardiovascular pathology including hypertension and heart failure. Evidence is now available that independently of the classical RAAS, several RAAS components are expressed in cells from different organs including the heart and kidney and are able to change important physiological properties like cell communication, heart excitability and activation of ionic channels and cell volume when applied locally to the cells (1) or systemically, independently of blood pressure. In cardiac cells, swelling induced by angiotensin II (Ang II), is counteracted by angiotensin (1-7) (Ang (1-7)) with consequent decrease of swelling-dependent chloride current helping the re-establishment of cell volume (2). Recently, it was found that Ang (1-7) re-establishes cell communication impaired by cell swelling in cardiac muscle raising the possibility of a beneficial effect of the hexapeptide during myocardial ischemia (3). These findings have important clinical implications (1, 4) and represent a novel and fruitful pathway to be followed to better understand the role of the RAAS in different pathological conditions. Furthermore, they offer the opportunity for the development of new therapeutic agents. Although studies performed on transgenic animals generated controversial results, evidence is available that the overexpression of some components of RAAS like angiotensin II on cardiac muscle, elicit ventricular hypertrophy independently of changes in arterial blood pressure (5). Furthermore, the identification of some of the RAAS components inside the cell including the nucleus and mitochondria (6,7,8) and the results achieved dialyzing Ang II or renin intracellularly (1,7), supports the notion that there is an intracellular component with functional properties (the intracrine effect) (1,7). In arterial myocytes from vascular resistance vessels, for instance, intracellular Ang II has an effect opposite to that of extracellular Ang II on vascular tone (9) suggesting an important intracrine effect of the peptide on peripheral resistance. Furthermore, the (pro) renin receptor (PRR), mainly located intracellularly (10,11), is a new member of the RAS, originally considered to be involved in the regulation of blood pressure. Recent observations using transgenic animals over-expressing PRR demonstrated that PRR is an accessory protein of V-ATPase that plays an important role in the regulation of several
%K renin-angiotensin systems
%K Editorial
%K RAAS
%K pathophysiology
%K Oxidative Stress
%U http://www.frontiersin.org/Journal/10.3389/fendo.2014.00104/full