Hyponyms (each of the following is a kind of lacrimator): chlorobenzylidenemalononitrile; CS gas (a tear gas that is stronger than CN gas but wears off faster; can be deployed by grenades or cluster bombs; can cause skin burns and fatal pulmonary edema)
Freebase(0.00 / 0 votes)Rate this definition: Renin. Renin, also known as an angiotensinogenase, is an enzyme that participates in the body's renin-angiotensin system âalso known as the renin-angiotensin-aldosterone axisâthat mediates extracellular volume, and arterial vasoconstriction.
Renin, a hormone produced by the juxtaglomerular apparatus in the kidneys, converts angiotensinogen (which is made in the liver) to angiotensin I. Angiotensin I is then converted to angiotensin II by the angiotensin converting enzyme (ACE), increasing blood pressure by causing vasoconstriction of the blood vessels.