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Human chorionic gonadotrophin inhibition of pregnant human myometrial contractility
Author(s) -
Slattery Michael M.,
Brennan Cara,
O'Leary Michael J.,
Morrison John J.
Publication year - 2001
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.1471-0528.2001.00178.x
Subject(s) - myometrium , contractility , endocrinology , medicine , isometric exercise , human chorionic gonadotropin , uterus , tocolytic , chemistry , pregnancy , hormone , biology , gestation , preterm labor , genetics
Objective To evaluate the effect of human chorionic gonadotrophin (hCG) on pregnant human myometrial contractility in vitro and to determine whether the hCG‐elicited effect was oestrogen dependant. Methods Isometric tension recording was performed under physiological conditions in isolated myometrial strips from biopsies obtained at elective caesarean section. The effect of cumulative additions of hCG (0.001, 0.01, 0.1, 1.0 and 10 iu/mL) on myometrial contractility was evaluated. Secondarily, the contractile activity of pregnant myometrium following hCG exposure was investigated in tissue pre‐treated with beta‐oestradiol. Results hCG exerted a statistically significant relaxant effect on pregnant human myometrial tissue. The relaxant effect increased with increasing concentrations of hCG from 8.96% (SEM 2.06) (0.001 iu/mL hCG; P <0.01) to a net cumulative total of 58.50% (SEM 3.74) (10 iu/mL hCG; P <0.01). The relaxant effect was also time‐dependant, increasing in magnitude throughout the duration of experiments. Beta‐oestradiol did not significantly affect the response of myometrial tissue to hCG. Conclusions These results clearly demonstrate that hCG exerts a significant concentration‐dependant relaxant effect on human myometrial tissue obtained rate in pregnancy. These findings outline an inhibitory physiological role of hCG on human myometrial contractility and raise the possibility of its potential use as a tocolytic.