AngiotensinIISynthese

AngiotensinIISynthese refers to the biochemical process by which Angiotensin II is produced in the body. This peptide hormone plays a crucial role in regulating blood pressure, fluid balance, and electrolyte homeostasis. The synthesis of Angiotensin II is a key component of the renin-angiotensin-aldosterone system (RAAS).

The process begins with the enzyme renin, which is released by the kidneys in response to low blood pressure or reduced sodium levels. Renin acts on angiotensinogen, a precursor protein produced by the liver, cleaving it to form angiotensin I. Angiotensin I is an inactive decapeptide.

Subsequently, angiotensin I is converted to the active octapeptide Angiotensin II by the enzyme angiotensin-converting enzyme (ACE). ACE is found primarily in the endothelial cells of the lungs, but also in other tissues. This conversion is the rate-limiting step in the formation of Angiotensin II.

Once formed, Angiotensin II exerts its effects by binding to specific receptors, primarily Angiotensin II type 1 (AT1) receptors, found on various cells and tissues. This binding leads to vasoconstriction, increased aldosterone secretion from the adrenal cortex, and stimulation of the sympathetic nervous system, all of which contribute to an increase in blood pressure. It also plays a role in cell growth and inflammation. The synthesis and action of Angiotensin II are therefore tightly regulated to maintain cardiovascular homeostasis.