An Update on the Tissue Renin Angiotensin System and Its Role in Physiology and Pathology

Abstract

In its classical view, the renin angiotensin system (RAS) was defined as an endocrinesystem involved in blood pressure regulation and body electrolyte balance. However, the emergingconcept of tissue RAS, along with the discovery of new RAS components, increased thephysiological and clinical relevance of the system. Indeed, RAS has been shown to be expressed invarious tissues where alterations in its expression were shown to be involved in multiple diseasesincluding atherosclerosis, cardiac hypertrophy, type 2 diabetes (T2D) and renal fibrosis. In thischapter, we describe the new components of RAS, their tissue-specific expression, and theiralterations under pathological conditions, which will help achieve more tissue- and conditionspecifictreatments.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may be harmful in patients with diabetes during COVID-19 pandemic

“…This event leads to the conversion of angiotensin I to angiotensin 1-9 [1e3]. Angiotensin 1-9 is converted to angiotensin 1-7 by ACE2 [1,2]. Angiotensin receptor antagonists (ARBs) prevent angiotensin II from binding to the receptor, thus ARBs inhibit the effect of angiotensin II.…”

Therapeutic Renin Inhibition in Diabetic Nephropathy—A Review of the Physiological Evidence

“…Locally activated synthesis and activity of renin have been identified in kidney and other organs in different pathologies (Bader et al, 2001). Such organs where a local tissue RAS has been postulated include the heart, blood vessels, kidney, brain, adipose tissue, adrenal gland, pancreas, liver, reproductive system, lymphatic tissue, placenta, and eyes (Nehme et al, 2019). Diseases where chronically activated local tissue RAS has been identified include HTN, atherosclerosis, heart failure, cardiac hypertrophy and fibrosis, chronic kidney disease, and glaucoma (Ames et al, 2019;Nehme et al, 2019).…”

“…Such organs where a local tissue RAS has been postulated include the heart, blood vessels, kidney, brain, adipose tissue, adrenal gland, pancreas, liver, reproductive system, lymphatic tissue, placenta, and eyes (Nehme et al, 2019). Diseases where chronically activated local tissue RAS has been identified include HTN, atherosclerosis, heart failure, cardiac hypertrophy and fibrosis, chronic kidney disease, and glaucoma (Ames et al, 2019;Nehme et al, 2019). An increase in local production of active angiotensins could be through the classical renin-ACE pathway or through alternative pathways (Ferrario et al, 2014).…”

Pathological Role of Angiotensin II in Severe COVID-19

“…31 The RAS is known for its role in the regulation of blood pressure, electrolyte balance, and vascular remodeling. 32 Continuous basic and clinical research has enabled significant advances in therapy and developed the treatment of hypertension and left ventricular dysfunction as well as severe heart failure.…”