Lipid and protein peroxidation process and catalase activity in pre-eclamptic placenta

There are some suggestions that free radicals are involved in some dysfunctions observed in preeclampsia. In this study we have examined the antioxidant status of preeclamptic placentas. We have used placentas obtained from normal pregnant women and women with preeclampsia. Lipoperoxidative process was measured by means of Okhawa method. Sedlak method was used to measured the total thiol groups. The catalase activity was measured by means of Pffeifer method. The results show that the catalase activity decreases, the amount of MDA increases and the total amount of thiol groups is smaller in preeclamptic placentas. The level of lipid peroxides in preeclamptic placentas is about 1.8 times higher in comparison with normal placentas. The decreased level of total thiol groups in preeclamptic placentas can be caused by a more intensive process of protein peroxidation. Catalase is less active in preeclamptic placentas. It can be due to lower activity of antioxidant systems or the destruction of antioxidant systems by reactive oxygen species. The results of our experiments confirm lower antioxidant status in preeclamptic placentas and suggest that peroxidative reaction may cause many dysfunctions associated with preeclampsia.