Angiotensin Receptor Antibodies

The actions of angiotensin II (Ang II) are mediated by two types of mammalian receptors designated AT1 for angiotensin type 1 receptor and AT2 for angiotensin type 2 receptor. AT1 and AT2 receptors share around 30% sequence similarity. The decapeptide angiotensin I, the octapeptide angiotensin II and the heptapeptide angiotensin III are endogenous ligands. The human genome contains single genes for AT1 and AT2. In rodents and zebra fish two genes encoding subtypes AT1a and AT1b exist. Most actions of Ang II, such as maintainance of blood pressure and glomerular filtration rate in response to extracellular volume depletion are mediated through the AT1 receptor. The AT2 receptor mediated effects in various tissues indeed may critically require local conversion of Ang II to Ang III through the involvement of resident aminopeptidase in specific tissues such as kidney and brain. Losartan, candesartan, telmisartan, etc. are clinically used AT1 receptor blockers.