Renin (etymology and pronunciation), also called an angiotensinogenase, is an aspartic protease protein and enzyme secreted with the aid of the kidneys that participates within the body renin–angiotensin& aldosterone system (RAAS) additionally referred to as the renin–angiotensin & aldosterone  that mediates the extent of extracellular fluid Renin can also be known as a hormone, because it has a receptor, the (pro)renin receptor, additionally known as the renin receptor and prorenin receptor (see also beneath), in addition to enzymatic interest with which it hydrolyzes angiotensinogen to angiotensin Renin turns on the renin–angiotensin device via cleaving angiotensinogen, produced via the liver, to yield angiotensin I, that further converted into angiotensin II with the aid of ACE, the angiotensin–changing enzyme by and large within the capillaries of the lungs. Angiotensin II then constricts blood vessels, will increase the secretion of ADH and aldosterone, and stimulates the hypothalamus to set off the thirst reflex, every leading to an growth in blood pressure. Renin primary characteristic is therefore to subsequently cause an increase in blood stress, main to recovery of perfusion stress inside the kidneys.Renin is secreted from juxtaglomerular kidney cells, which sense adjustments in renal perfusion pressure, thru stretch receptors in the vascular partitions. The juxtaglomerular cells are also inspired to release renin by means of signaling from the macula densa. The macula densa senses adjustments in sodium shipping to the distal tubule, and responds to a drop in tubular sodium load by stimulating renin launch within the juxtaglomerular cells. collectively, the macula densa and juxtaglomerular cells incorporate the juxtaglomerular complicated.Renin secretion is likewise inspired by using sympathetic apprehensive stimulation, specially through adrenoreceptor activation.