Angiotensin II receptor subtypes: characterization, signalling mechanisms, and possible physiological implications.

Thanks to the recent discovery of angiotensin II (ANG II) receptor subtypes linked to different signalling pathways, research in the different areas related to this peptide has regained a strong interest. In the following review, we first describe the biochemistry and actions of angiotensin peptides formed both in the circulation and locally at the tissue and organ level. Evidence for the existence and distribution of ANG II receptor subtypes in mammalian as well as in nonmammalian species and lower organisms is presented. The changes in receptor subtype expression during development and disease are described. The signal transduction mechanisms and biological actions of ANG II mediated by the recently cloned AT1 receptor are reviewed and the recent data concerning the signalling pathways linked to the AT2 receptor are discussed. Finally, based upon their molecular pharmacology, we present evidence and also speculate upon the physiological function of the ANG II receptor subtypes.