EFFECTS OF MAGNESIUM-SULFATE INFUSION UPON PLASMA PROSTAGLANDINS IN PREECLAMPSIA AND PRETERM LABOR

Objective: Recent investigation has shown that magnesium stimulates th e release of prostacyclin from confluent endothelial cell cultures. Th e goal of this study was to determine the effect of magnesium sulfate infusion on the peripheral concentrations of prostaglandin E(2) (PGE(2 )), prostaglandin F-2 alpha (PGF(2 alpha)) and 6-keto-prostaglandin F- 1 alpha (6-keto-PGF(1 alpha), the stable metabolite of prostacyclin) i n women with either preeclampsia or preterm labor. We hypothesized tha t plasma prostacyclin concentrations would increase during magnesium s ulfate infusion in women with preeclampsia to a greater extent than in women with preterm labor. Methods: Twenty-one women with preeclampsia and 14 women in preterm labor were enrolled in a prospective study fo llowing transfer to a tertiary center. Blood samples were obtained pri or to initiating the magnesium sulfate infusion, immediately after a 4 -g load and 2 h later during a maintenance infusion of 2 g/h. Main Out come Measures: 6-keto-PGF(1 alpha), PGE(2), and PGF(2 alpha) concentra tions were measured at baseline, immediately after the magnesium sulfa te loading dose, and 2 h later during the magnesium sulfate maintenanc e infusion. Results: During the magnesium sulfate infusion, 6-keto-PGF (1 alpha) rose in the women with preeclampsia from 30.5 pg/mL to 101.6 pg/mL (P = 0.01). No significant change in 6-keto-PGF(1 alpha) concen tration was observed in the women with preterm labor No significant ch ange was noted in the concentrations of PGE(2) or PGF(2 alpha) in eith er group during magnesium sulfate infusion. Conclusions: This study pr ovides in vivo support for the premise that magnesium sulfate infusion can stimulate prostacyclin release in women with preeclampsia.