Circulatory responses of perinatal goats to prostaglandin precursors

The effects of precursors in the prostaglandin synthetic pathway as well as those of analogs of cyclic endoperoxide intermediates upon the pulmonary and systemic circulations of fetal and newborn goats were examined. Exogenous arachidonic acid increased pulmonary vascular resistance and decreased systemic arterial pressure of fetuses and newborns. The effects of dihomo-gamma-linolenic acid on the circulation are qualitatively similar, but quantitatively less, than those of arachidonic acid. The cyclic endoperoxide analogs were strong pressors in both pulmonary and systemic circulations. The responses to the fatty acid precursors, which are totally blocked by indomethacin and meclofenamate, appear to indicate that they give rise to more than one vasoactive product. Furthermore, exogenous arachidonic acid produces effects which appear to be different from those produced by endogenous pulmonary arachidonic acid.