  the angiotensin receptors are a class of g protein-coupled receptors with angiotensin ii as their ligands. they are important in the renin-angiotensin system: they are responsible for the signal transduction of the vasoconstricting stimulus of the main effector hormone, angiotensin ii. ==structure== the at1 and at2 receptors share a sequence identity of ~30%, but have a similar affinity for angiotensin ii, which is their main ligand. ==members== ===overview table=== {| class="wikitable" !receptor !mechanismunless else specified in box, then ref is: senselab |- !at1 || *gq/11 *gi/o |- !at2 || * gi2 / 3 |- !at3 || |- !at4 || |- |} losartan is a selective at1 antagonist,while pd123177 is a selective at2 antagonist.both subtypes are g-protein coupled receptor. ===at1===  the at1 receptor is the best elucidated angiotensin receptor. ====location within the body==== the at1 subtype is found in the heart, blood vessels, kidney, adrenal cortex, lung and brain and mediates the vasoconstrictor effects. ====mechanism==== the angiotensin receptor is activated by the vasoconstricting peptide angiotensin ii. the activated receptor in turn couples to [[gq 
G_protein_coupled_receptors Genes_on_chromosome_3 Genes_on_chromosome_X