Angiotensin Receptors

The angiotensin family of peptides is important in the regulation of blood volume, vascular resistance and electrolyte balance. Angiotensin II, the main peptide of the renin-angiotensin system, produces a variety of physiological effects. It is produced in a cascade whereby the precursor peptide angiotensinogen is cleaved to produce renin and angiotensin I. Angiotensin-converting enzyme then acts on angiotensin I to yield the octapeptide angiotensin II, and further processing generates angiotensin III and IV. These peptides act on three angiotensin receptor subtypes, AT₁, AT₂ and AT₄, the properties of which are summarized below. The actions of angiotensin II are primarily mediated by AT₁, whereas AT₂ preferentially binds angiotensin III and AT₄ is selective for angiotensin IV.