Renin Release

Frank Schweda 1 , Ulla Friis 2 , Charlotte Wagner 1 , Ole Skott 2 and Armin Kurtz 1 1 Institute of Physiology, University of Regensburg, Germany; and 2 Department of Physiology and Pharmacology, Southern Denmark University at Odense, Odense, Denmark armin.kurtz{at}vkl.uni-regensburg.de The aspartyl-protease renin is the key regulator of the renin-angiotensin-aldosterone system, which is critically involved in salt, volume, and blood pressure homeostasis of the body. Renin is mainly produced and released into circulation by the so-called juxtaglomerular epithelioid cells, located in the walls of renal afferent arterioles at the entrance of the glomerular capillary network. It has been known for a long time that renin synthesis and secretion are stimulated by the sympathetic nerves and the prostaglandins and are inhibited in negative feedback loops by angiotensin II, high blood pressure, salt, and volume overload. In contrast, the events controlling the function of renin-secreting cells at the organ and cellular level are markedly less clear and remain mysterious in certain aspects. The unravelling of these mysteries has led to new and interesting insights into the process of renin release.