Renin (etymology and pronunciation), also known as an angiotensinogenase, is a serine protease protein and enzyme secreted by the kidneys that participates in the body 's renin - angiotensin aldosterone system (RAAS) -- also known as the renin - angiotensin - aldosterone axis -- that mediates the volume of extracellular fluid (blood plasma, lymph and interstitial fluid), and arterial vasoconstriction. Thus, it regulates the body 's mean arterial blood pressure.
what part of the kidney senses changes in blood pressure
Renin renin renin