| Abstrakt: |
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 0804–4643We 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 laevisoocyte 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 |
