The effect of a calcium channel blocker (nifedipine) on uterine blood flow in the pregnant goat.

The purpose of this study was to analyze the changes in maternal uterine blood flow, maternal arterial blood pressure, and maternal heart rate with the intravenous administration of nifedipine in pregnant, unanesthetized pygmy goats. Bolus injections of 2.5 to 45 micrograms/kg of maternal weight were used. Uterine blood flow did not fall significantly. A transient fall in maternal arterial blood pressure occurred in the first minute after the injection, but the pressure returned to normal after 5 minutes. Maternal heart rate increased immediately after the bolus of nifedipine and returned toward the control value by 30 minutes.