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Specific PGF 2α receptor (FP) antagonism and human uterine contractility in vitro
Author(s) -
Friel Anne M.,
O'Reilly Michael W.,
Sexton Donal J.,
Morrison John J.
Publication year - 2005
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.2005.00658.x
Subject(s) - myometrium , contractility , phenylephrine , oxytocin , medicine , endocrinology , uterine contraction , hysterectomy , antagonism , oxytocin receptor , uterus , agonist , population , contraction (grammar) , antagonist , receptor , surgery , blood pressure , environmental health
Objective PGF 2α acts through its receptor, FP, as an important smooth muscle contractile agent. The aim of this study was to investigate the effects of specific FP antagonism, using the novel‐specific FP non‐competitive antagonist THG113.31, on spontaneous and agonist‐elicited contractions in pregnant and non‐pregnant human myometrium in vitro . Design Scientific study. Setting University hospital and laboratories. Population Women undergoing caesarean section or hysterectomy. Methods Biopsies of human myometrium were obtained at elective caesarean section ( n = 22) and from hysterectomy specimens from premenopausal women ( n = 8). Dissected strips were mounted in tissue baths under physiological conditions. The effects of THG113.31 on spontaneous and oxytocin‐induced contractions, in pregnant myometrium, and on phenylephrine‐induced contractions, in non‐pregnant myometrium, were measured. The effects of PGF 2α on spontaneous contractions, in pregnant tissue, in the presence and absence of THG113.31, were investigated. The integrals of contractile activity measured were compared with those from simultaneously run control experiments. The pD 2 and mean maximal effect observed for THG113.31, and for PGF 2α in the presence and absence of THG113.31, were calculated. Main outcome measures Changes in contractility. Results THG113.31 exerted a potent relaxant effect in both spontaneous and oxytocin‐induced contractility in pregnant tissue ( P < 0.001), and phenylephrine‐induced contractility in non‐pregnant tissue ( P < 0.001), compared with control experiments. PGF 2α exerted a significant contractile effect on spontaneous contractions in pregnant tissue and this effect was not significantly attenuated by THG113.31 ( P > 0.05). Conclusion THG113.31 exerted a significant relaxant effect on human spontaneous and oxytocin‐induced contractility but did not alter PGF 2α ‐elicited contractility. These data raise questions about the exact mechanism of effect of THG113.31 and its interaction with FP. The uterorelaxant potency of THG113.31 in human myometrium in vitro indicates that it may be of limited use as a tocolytic compound.