Abstract
Objective: Recent investigation has shown that magnesium stimulates the release of prostacyclin from confluent endothelial cell cultures. The goal of this study was to determine the effect of magnesium sulfate infusion on the peripheral concentrations of prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α) and 6-keto-prostaglandin F1α (6-keto-PGF1α the stable metabolite of prostacyclin) in women with either preeclampsia or preterm labor. We hypothesized that plasma prostacyclin concentrations would increase during magnesium sulfate 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 following transfer to a tertiary center. Blood samples were obtained prior 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 Outcome Measures: 6-keto-PGF1α PGE2 and PGF2α concentrations were measured at baseline, immediately after the magnesium sulfate loading dose, and 2 h later during the magnesium sulfate maintenance infusion.
Results: During the magnesium sulfate infusion, 6-keto-PGF1α 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-PGF1α concentration was observed in the women with preterm labor. No significant change was noted in the concentrations of PGE2 or PGF2α in either group during magnesium sulfate infusion.
Conclusions: This study provides in vivo support for the premise that magnesium sulfate infusion can stimulate prostacyclin release in women with preeclampsia.