Lipid peroxidation, antioxidant defense, status of trace metals and leptin levels in preeclampsia.

OBJECTIVE: To investigate the changes in enzyme activities of erythrocyte superoxide dismutase (SOD), catalase, and placental glutathione peroxidase (GSH-Px), and analyze the levels of serum malondialdehyde (MDA), copper (Cu), zinc (Zn), selenium (Se), leptin and placental MDA and glutathione (GSH).

STUDY DESIGN: Cross-sectional prospective study consisting of 32 preeclamptic (PE) pregnant, 25 non-pregnant (NP) women, 28 healthy pregnant (HP) women. Levels of lipid peroxides in serum and placenta, and activities of SOD, catalase in erythrocyte and placental GSH level, placental GSH-Px activity were measured by spectrophotometric methods. Serum levels of Cu, Zn, Se measured by atomic absorption spectrophotometry. Serum levels of leptin was measured by enzyme immunoassay by using the Cayman chemical kit. One-way analysis of variance and post hoc Tukey-HSD test and Pearson correlation test were used for the statistical analyses.

RESULTS: Serum levels of MDA, Cu, Leptin were markedly higher (P < 0.001); and serum level of Se was markedly lower (P < 0.001) in PE women compared with HP women and NP women. Also, placental MDA level was higher (P < 0.001) and placental GSH-Px activity was lower in PE women compared with HP women. In preeclamptic women erythrocyte catalase activity was markedly increased (P < 0.001), while erythrocyte SOD activity was markedly decreased (P < 0.001) compared to HP women and NP women. Placental GSH level was decreased compared to HP women (P < 0.001). Serum level of Zn was markedly decreased compared to NP women (P < 0.001) but no significant difference was observed in PE pregnant when compared with HP women (P > 0.05). Placental MDA level in PE women had significant negative correlation with serum Se level (r = -0.353, P < 0.05). A negative correlation was found between erythrocyte catalase activity with birth weight (r = -0.528, P < 0.001). Also, there were a significant negative correlation between serum levels of Cu and Se in the preeclamptic women (r = -0.407, P < 0.05).

CONCLUSION: Our data demonstrate that elevation of lipid peroxides together with impaired antioxidant defense mechanisms and status of trace metals and the presence of possible interrelationship and crosstalk between those parameters may be related at least partly to the pathogenesis of preeclampsia. Additionally, lipid peroxides and blood oxidative imbalance could be part of the cytotoxic mechanisms leading to endothelial cell injury.