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 is a protein (enzyme) released by special kidney cells when you have a decreased salt (sodium) level or low blood volume. If you have high blood pressure, your doctor may order a renin and aldosterone test to help determine the cause of your elevated blood pressure. Test results can help guide your doctor in choosing the correct treatment.