The effect of SAR1ALA8 AII on ovine uterine and umbilical blood flow

The effects of Sar1Ala8 AII (Saralasin), an angiotensin II (AII) receptor blocker, were examined in the late gestation ewe and fetus. Maternal administration of Saralasin resulted in a reduction in both mean maternal systemic arterial pressure and uterine blood flow. There were no changes in the measured fetal indices during maternal drug administration. Infusion of Saralasin to the fetus caused variable reductions in mean fetal arterial blood pressure and umbilical flow. There were no changes in maternal parameters measured. Therefore, in pregnant sheep in the third trimester, a component of normal uterine blood flow is maintained by endogenous AII, primarily through maintenance of adequate perfusion pressure.