A New Perspective on the Renin-Angiotensin System

Cardiovascular disease (CVD) is the leading cause of death in the world. Hypertension is a serious medical problem not only in adults but also in children and adolescents. The renin-angiotensin-aldosterone system (RAAS) is one of the most important mechanisms regulating blood pressure and the balance of water and electrolytes. According to the latest reports, RAAS acts not only on endocrine but also on paracrine, autocrine, and intracrine. Moreover, RAAS has a component associated with hypotension and cardioprotective effects. These components are called alternative pathways of RAAS. The most important peptide of the alternative pathway is Ang 1–7, which is related to the Mas receptor. Mas receptors have widely known antihypertension properties, including vasodilatation, the release of nitric oxide, and increased production of anti-inflammatory cytokines. Another interesting peptide is angiotensin A, which combines the properties of the classical and alternative pathways. No less important components of RAAS are the proteolytic enzymes angiotensin convertase enzyme type 1 and 2. They are responsible for the functioning of the RAAS system and are a hypertension therapeutic target. Also involved are tissue-specific enzymes that form a local renin-angiotensin system. Currently, a combination of drugs is used in hypertension treatment. These drugs have many undesirable side effects that cannot always be avoided. For this reason, new treatments are being sought, and the greatest hope comes from the ACE2/ang 1–7/MasR axis.