Uterine and systemic vascular responses to dopamine in pregnant ewes.

The systemic and uterine hemodynamic effects of dopamine were studied in six near-term pregnant Texel sheep. Dopamine was administered by i.v. infusion in doses ranging from 2 to 16 micrograms per kilogram per minute. After administration of 2 and 4 micrograms/kg/min, Dopamine produced a statistically significant increase in uterine blood flow (p less than 0.02). The mean value of the increase was 68.3 ml/min. When doses of 8 and 16 micrograms/kg/min were given, the responses were variable. Systolic and diastolic arterial pressure remained unchanged up to dopamine dosages of 8 micrograms/kg/min. Heart rate also showed no significant increase but a trend in this direction was seen. Low-dosages of dopamine could be used in the treatment of patients with placental insufficiency.