LIPOPEROXIDATION AND ANTIOXIDANT ENZYMES ACTIVITY IN PREGNANCY COMPLICATED WITH HYPERTENSION

Objective: To assess maternal circulating levels of lipid peroxidation breakdown products and antioxidant enzymes activity in pregnancies co mplicated with hypertension. Study design: Ten women with uncomplicate d pregnancies and nine women with hypertension antedating pregnancy we re prospectively sampled. Eight women, who had developed preeclampsia, were also cross-sectionally included. Twenty healthy non pregnant vol unteers were the control group. Thiobarbituric acid reactive substance s (TBA-RS), as lipid peroxidation products, and the activity of catala se (CAT), glutathione peroxidase (GPX) and superoxide dismutase (SOD), as antioxidant enzymes, were assayed in red blood cell hemolysates. A prooxidant/antioxidant (P/A) ratio (TBA-RS/CAT + GPX + SOD) was deter mined from the mean value of the volunteers. Results: In women with ch ronic hypertension, TBA-RS levels were higher than those in normal pre gnant women: whereas antioxidant enzymes activities were either stable or decreased. Therefore the P/A ratio was progressively lower in the second and third trimester. Similar results were found in patients wit h preeclampsia. Conclusions: Normal gestation induces an increase of l ipid peroxidation products, whereas antioxidant activity seems stable. In pregnancies complicated by chronic hypertension, a deficiency of t he oxidative system balance is detectable, which consistently progress es in the second and third trimester, strongly suggesting a failure of the protective mechanisms. Copyright (C) 1996 Elsevier Science Irelan d Ltd.