The effect of oxytocin antagonist on uterus in response to exogenous oxytocin.
10.3346/jkms.2000.15.3.299
- Author:
Suk Hyun PARK
1
;
Chang Hun SONG
;
Sok Cheon PAK
;
George FLOURET
;
Laird WILSON
Author Information
1. Department of Obstetrics and Gynecology, Medical School, Chosun University, Kwangju, Korea.
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Oxytocin, Oxytocin Antogonist;
Uterus;
Receptor;
Labor
- MeSH:
Animal;
Female;
Oxytocin/pharmacology;
Oxytocin/metabolism;
Oxytocin/antagonists & inhibitors*;
Rats;
Receptors, Oxytocin/metabolism;
Uterus/physiology;
Uterus/drug effects*
- From:Journal of Korean Medical Science
2000;15(3):299-302
- CountryRepublic of Korea
- Language:English
-
Abstract:
This study was performed to determine the action mode of oxytocin antagonist. In Study 1, the duration of in vivo action of oxytocin antagonist I (AI) was examined. After infusing AI, oxytocin was given and repeated every hour for 5 hr. Uterine activities were monitored with a polygraph. Study 2 determined the effect of AI on uterine oxytocin receptor number (Rn) and binding affinity (Kd). AI treated rats were sacrificed at 0.5 and 4 hr later for receptor assay. In Study 1, the uterine contractile response to oxytocin was significantly inhibited (p>0.05) compared to controls at five min, 1 and 2 hr after injection of AI. No differences in response were detected compared to controls (p>0.05) at later hours. In Study 2, no differences (p>0.05) between the AI and control animals in either oxytocin receptor number or binding affinity was found. These data suggest that the major mode of AI action is via competitive inhibition at the uterine oxytocin receptor and not by altering receptor number or binding affinity. AI is suggested to have the potential of being a potent and specific tocolytic agent for prevention of preterm labor in human.
