Protective Effects of Prostaglandin E2 on the Paraquat-Induced Constriction of the Fetal Ductus Arteriosus in the Rat.

Abstract

Pregnant rats on day 21 of gestation received a subcutaneous injection of paraquat (25 mg/kg). Two hr later, some fetuses of these rats received a subcutaneous injection of prostaglandin E2 (PGE2). The caliber of the ductus arteriosus (DA) of fetuses was measured 1 hr later. The DA of fetuses of paraquat-treated pregnant rats was significantly constricted compared with that of fetuses of control pregnant rats given physiological saline. However, the DA of PGE2-treated fetuses of paraquat-treated pregnant rats had a caliber comparable to that of control rats. The maternal plasma PGE2 level decreased following paraquat treatment. These results suggest that the decrease of maternal PGE2 level results in a constriction of the DA of fetuses.