Angiotensiini17ksi

Angiotensin II (ATII) is a potent peptide hormone that plays a crucial role in the regulation of blood pressure and fluid balance in the body. It is a product of the renin-angiotensin system (RAS), a complex physiological pathway that helps maintain homeostasis. The RAS is initiated by the enzyme renin, which is released by the kidneys in response to low blood pressure or low sodium levels. Renin acts on angiotensinogen, a plasma protein, to produce angiotensin I (ATI). Angiotensin-converting enzyme (ACE) then converts ATI into ATII.

ATII exerts its effects through two main mechanisms: direct vasoconstriction and the stimulation of aldosterone release. Direct vasoconstriction leads to increased blood pressure, while the stimulation of aldosterone promotes sodium and water retention, further elevating blood pressure. These effects are mediated through the angiotensin II type 1 (AT1) receptor, which is widely expressed in various tissues, including blood vessels, heart, and kidneys.

ATII also plays a role in the development of cardiovascular diseases, such as hypertension and heart failure. Chronic activation of the RAS can lead to endothelial dysfunction, inflammation, and fibrosis, contributing to the progression of these conditions. Therefore, inhibiting the RAS with medications like ACE inhibitors or angiotensin II receptor blockers (ARBs) is a common therapeutic approach for managing hypertension and heart failure.

In summary, angiotensin II is a key player in the renin-angiotensin system, regulating blood pressure and fluid balance. Its effects are mediated through the AT1 receptor, and its chronic activation is associated with cardiovascular diseases. Understanding the role of ATII in the RAS is essential for the development of effective treatments for hypertension and heart failure.