Author:
Kimura Tadashi,Makino Yoko,Saji Fumitaka,Takemura Masahiko,Inoue Tomoko,Kikuchi Tomoyuki,Kubota Yasue,Azuma Chihiro,Nobunaga Toshikatsu,Tokugawa Yoshihiro,Tanizawa Osamu
Abstract
Kimura T, Makino Y, Saji F, Takemura M, Inoue T, Kikuchi T, Kubota Y, Azuma C, Nobunaga T, Tokugawa Y, Tanizawa O. Molecular characterization of a cloned human oxytocin receptor. Eur J Endocrinol 1994;131:385–90. ISSN 0804–4643
We describe here the binding and functional properties of a cloned human oxytocin receptor (OTR). We established a transient OTR expression system on COS-1 cells, which do not express vasopressin receptors. With the transfected cells and [3H]oxytocin, the dissociation constant (Kd) of OTR to oxytocin was 6.0 ±1.1 nmol/l; the binding properties of several oxytocin-related peptides were also examined. The functional properties of OTR were determined by an electrophysiological method, using a Xenopus laevis oocyte injected with in vitro transcribed OTR mRNA. These two methods showed that [Phe2,Orn8]vasotocin, a vasopressin agonist, was an OTR antagonist. A combination of these methods using cloned OTR cDNA is a novel and effective method for the investigation of oxytocin-related ligands.
Tadashi Kimura, Department of Obstetrics and Gynecology, Osaka University Medical School, 2-2 Yamadaoka, Suita City, Osaka 565, Japan
Subject
Endocrinology,General Medicine,Endocrinology, Diabetes and Metabolism