AT4 receptors: Specificity and distribution

Abstract

The AT4 receptor specifically binds Angiotensin (Ang) IV and is distinct from the AT1 and AT2 receptors which bind Ang II and Ang III. The AT4 receptor in bovine adrenal cortex has a K(d) of 0.74 ± 0.14 nM and a B(max) of 3.82 ± 1.12 pmol/mg prot. Competition curves demonstrated the following rank order of affinity: Ang IV >> Ang III >> d-Arg - Ang II >> Sar1, Ile8 - Ang II = Ang II = Ang II (1-7) >> DuP753 = CGP42112A = PD 123177. AT4 receptors were present in many tissues from several mammalian species including human and monkey. AT4 and AT1/AT2 receptors revealed a differential distribution in the rat kidney.