British journal of obstetrics and gynaecology
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Br J Obstet Gynaecol · Aug 1988
Randomized Controlled Trial Clinical TrialStudies on the effects of nitrendipine on oxytocin-, angiotensin II- and ergometrine-induced contraction of pregnant human myometrium in vitro.
Calcium channel blockers inhibit myometrial contractility by preventing the increase in intracellular free calcium which follows stimulation. They could thus be useful in treating premature labour. The effect of nitrendipine, a dihydropyridine calcium channel antagonist, on the contractile response of strips of pregnant human myometrium to oxytocin, angiotensin II (AII) and ergometrine has been examined. ⋯ The initial EC50S for tissues exposed to ergometrine was 3.9 X 10(-8)M. Exposure to nitrendipine blunted the response (ANOVA; P less than 0.001), an effect most marked at low concentrations of ergometrine. The effect of nitrendipine on myometrial responses to the naturally occurring hormones oxytocin and AII supports suggestions of a role for it in inhibiting premature labour.