Lipid Peroxidation and Preeclampsia (Part 1)

Abstract

The influences of lipid peroxidation on the impairment of placental microcirculation in preeclampsia were studied.Lipid peroxides and vitamin E concentrations in the blood and the placental brush border membrane (PBBM) of the women with preeclampsia were measured by the TBA and HPLC methods, and the platelet aggregation inhibitory activity and ADP degrading activity of PBBM were analyzed using Born's Method and 14C-ADP degrading assay. Lipid peroxides concentrations both in the blood and in the PBBM were significantly increased (p<0.001, p<0.01 respectively), but plasma vitamin E concentrations were significantly reduced (p<0.01) in the women with preeclampsia. Significant reduction of platelet aggregation inhibitory activity (p<0.005) and ADP degrading activity (p<0.001) of PBBM were observed in preeclampsia. The influences of artificial peroxidation of PBBM by tertiary-butylhydroperoxide (t-BHP) on the platelet aggregation inhibitory activity and ADP degrading activity of PBBM were investigated in vitro assay using normal PBBM. Significant reduction of platelet aggregation inhibitory activity (p<0.005) and ADP degrading activity (p<0.001) of PBBM were observed in this artificially peroxidated PBBM. The effects of vitamin E on the artificial peroxidation of t-BHP were also investigated in the same in vitro assay. Vitamin E prevented the artificial peroxidation of PBBM, and at the same time the platelet aggregation inhibitory activity and ADP degrading activity of PBBM were reduced depending on the concentration (p<0.005, p<0.001). Furthermore, high concentrated vitamin E (500 μg/ml) demonstrates platelet aggregation inhibitory activity by itself, and low concentrated vitamin E (20μg/ml) promotes the potential platelet aggregation inhibitory activity of PBBM.These results suggests that lipid metabolism in the women with preeclampsia are under severe oxidative stress, and that in preeclampsia, the lipid peroxidation of PBBM plays an important role on the impaired placental microcirculation by reducing the platelet aggregation inhibitory activity, and vitamin E preserves the platelet aggregation inhibitory activity by preventing the lipid peroxidation of PBBM or by another mechanism.