Molecular cloning of the canine angiotensin II receptor

Abstract
Canine aortic strip studies revealed insensitivity of angiotensin II (AII)‐induced aortic contraction to inhibition by the non‐peptide antagonist DuP753 (pK B = 6.7 ± 0.1). In order to determine the origin of this phenomenon we cloned the canine homologue of the AT1 AII receptor. Expression of this cDNA in COS‐7 cells indicated a low affinity of DuP753 for the cloned receptor (K D = 92 nM). The predicted amino acid sequence is highly homologous to other mammalian AT1 receptors; sequence comparisons suggest the pharmacological difference may be the result of a threonine residue in position 163 in the IVth transmembrane domain.