reniinangiotensiini

The renninangiotensin system, often abbreviated as RAS or RAAS, is a complex hormonal system that plays a crucial role in regulating blood pressure and fluid balance in the body. It is primarily activated when there is a drop in blood pressure or a decrease in the body's sodium levels. The system begins in the kidneys with the enzyme renin, which is released in response to these signals. Renin then acts on angiotensinogen, a protein produced by the liver, to form angiotensin I. Angiotensin I is then converted to angiotensin II by another enzyme, angiotensin-converting enzyme (ACE), which is found mainly in the lungs. Angiotensin II is a potent vasoconstrictor, meaning it narrows blood vessels, thereby increasing blood pressure. It also stimulates the adrenal glands to release aldosterone, a hormone that promotes sodium and water reabsorption by the kidneys, further contributing to increased blood volume and pressure. Additionally, angiotensin II can influence thirst and the release of antidiuretic hormone (ADH), which also helps conserve water. While essential for maintaining hemodynamic stability, dysregulation of the renninangiotensin system can contribute to conditions like hypertension, heart failure, and kidney disease, making it a significant target for therapeutic interventions.