Effects of magnesium sulfate on lipid peroxidation and blood pressure regulators in preeclampsia

Objectives: To investigate the status of lipid peroxidation and serum levels of several vasoactive substances in preeclamptic (PE) pregnant women before and during treatment with magnesium sulfate (MgSO4). Design and methods: The study population included 16 PE women. Circulating levels of malondialdehyde (NIDA), endothelin 1 (ET-1), nitric oxide (NO) metabolites, and calcitonin gene-related peptide (CGRP) were measured before (at admission) and during MgSO4 treatment (at delivery and 24 h postpartum). Results: At admission systolic and diastolic blood pressures were 157 +/- 3 mm Hg and 106 +/- 2 mm Hg, respectively, and decreased significantly during treatment at delivery and 24 h postpartum (P < 0.0001). Before treatment, serum MDA concentrations were 0.383 +/- 0.037 mumol/L, and decreased significantly during MgSO4 administration at delivery and 24 h postpartum (P < 0.0001). In contrast, serum ET-1 levels at 24 h postpartum were significantly higher as compared with those observed before treatment (79 +/- 3 versus 65 +/- 2 pg/mL, P = 0.002). Serum NO metabolite concentrations were 26 +/- 3 mumol/L, and no significant changes were observed during treatment. Serum levels of CGRP were 50 +/- 3 pg/mL at admission, and increased significantly at partum (P < 0.001). Serum ET-1 correlated negatively with NO metabolites before treatment (r = -0.69, P = 0.002), but not during treatment. In contrast, ET-1 correlated positively with serum CGRP levels during treatment (r = 0.73, P = 0.002 and r = 0.71, P = 0.002, at delivery and 24 h postpartum, respectively), but not before treatment. Conclusions: This study demonstrates that MgSO4 administration to PE pregnant women induced significant changes in lipid peroxidation, production of ET-1 and CGRP. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved.