From converting enzyme inhibition to angiotensin II receptor blockade: new insight on angiotensin II receptor subtypes in the kidney.

Since the discovery of renin, almost 100 years ago, all the components of the renin-angiotensin system have been characterized on a molecular level. Angiotensin II (Ang II) receptors can be grouped in two classes: AT1 and AT2 receptors. In addition to these receptor subtypes, several other Ang-II-binding sites with different properties have been identified. The majority of Ang II receptors in the kidney comprises the AT1 type, whereas AT2 receptors are only expressed by distinct structures such as the renal capsule and the juxtaglomerular apparatus. The vast majority of physiological functions of angiotensin II in the kidney are mediated through AT1 receptors. Important exceptions may be the pressure-induced natriuresis and chemotaxis for macrophages/ monocytes, as well as growth-suppressive effects which may be mediated by AT2 receptors.