The substance responsible for helping regulate blood pressure is renin. Renin is an enzyme that plays a crucial role in the renin-angiotensin-aldosterone system (RAAS), which is a hormone system that helps regulate blood pressure and fluid balance in the body.
Here's how renin works in regulating blood pressure:
1. When there is a decrease in blood pressure or volume, specialized cells in the kidneys release renin into the bloodstream.
2. Renin acts on a protein called angiotensinogen, which is produced by the liver, and converts it into angiotensin I.
3. Angiotensin I is then converted into angiotensin II by an enzyme called angiotensin-converting enzyme (ACE), primarily found in the lungs.
4. Angiotensin II is a potent vasoconstrictor, which means it causes blood vessels to constrict, leading to an increase in blood pressure.
5. Additionally, angiotensin II stimulates the release of the hormone aldosterone from the adrenal glands, which promotes the reabsorption of sodium and water in the kidneys, further increasing blood volume and pressure.
Therefore, renin is a key player in the complex system that helps regulate blood pressure by controlling vasoconstriction and fluid balance in the body.
