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Corticosteroids and fetal vasculature: effects of hydrocortisone, dexamethasone and betamethasone on human umbilical artery
Author(s) -
Potter S.M.,
Dennedy M.C.,
Morrison J.J.
Publication year - 2002
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.1471-0528.2002.01540.x
Subject(s) - betamethasone , umbilical artery , dexamethasone , medicine , hydrocortisone , vascular resistance , vasodilation , artery , corticosteroid , endocrinology , glucocorticoid , fetus , anesthesia , hemodynamics , biology , pregnancy , genetics
Objective To investigate the direct effects of corticosteroids on human umbilical artery resistance, in vitro . Design Prospective laboratory study. Setting University teaching hospital. Samples and methods Umbilical artery samples were obtained following normal, term deliveries ( n = 50 ) and dissected rings were suspended for isometric recording under physiological conditions. The effects of hydrocortisone ( 10 −9 –10 −4 M ), dexamethasone ( 10 −9 –10 −4 M ) and betamethasone ( 10 −9 –10 −4 M ) on umbilical artery resistance were measured in vitro . Main outcome measures Changes in umbilical artery resistance, in vitro . Results Hydrocortisone ( n = 12 ) exerted a vasodilatory effect on human umbilical artery at all concentrations studied compared with vehicle control experiments ( n = 12 ) ( P < 0.0001 ). The mean net relaxant effect of hydrocortisone ranged from 11.77% ( 10 −9 M ) to 57.01% ( 10 −4 ). Both exogenous compounds, dexamethasone ( n = 12 ) and betamethasone ( n = 12 ), similarly exerted a significant relaxant effect on human umbilical artery tone ( P < 0.05–0.01 ), compared with vehicle control experiments ( n = 12 ). The mean net relaxant effect of dexamethasone ranged from 14.43% ( 10 −9 M ) to 38.12% ( 10 −4 ) and that of betamethasone ranged from 6.02% ( 10 −9 M ) to 42.30% ( 10 −4 ), in a cumulatively increasing fashion. There was a non‐significant trend towards a greater vasodilatory effect of dexamethasone than betamethasone at lower bath concentrations studied. Conclusion Corticosteroids exert a direct and potent vasodilatory effect on human umbilical artery resistance in vitro , thus providing an explanation for the previously unexplained vascular effects associated with antenatal administration of corticosteroids.