Lipid peroxidation products and antioxidant enzymes in red blood cells during normal and diabetic pregnancy.

Oxygen free radicals produced during normal aerobic metabolism have been implicated in several pathophysiological mammalian processes. The importance of free radical-mediated fatty acid oxidation has received much attention. The generation of active oxygen species may lead to lipid peroxidation and formation of reactive products, which may be involved in severe damage of cell molecules and structures. Free radical metabolism in pregnancy and in diabetes mellitus is still unclear. To add new insights to the question, changes in lipid peroxidation products and activities of three antioxidant enzymes: catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase (SOD) in maternal red blood cells haemolysates were evaluated in pregnant women with insulin-dependent diabetes mellitus (IDDM-PW) and in healthy pregnant women (HPW). Healthy non-pregnant women were the control group for IDDM-PW and HPW, respectively. Pregnancy provoked an increase of lipoperoxidation products and an high SOD activity since early pregnancy, while CAT and GPX activities did not change during gestation. IDDM-PW showed higher content of lipoperoxidation breakdown products and lower SOD activity at each trimester, if compared with HPW; moreover, a slight increase of CAT and SOD activity is reported during late diabetic pregnancy. IDDM-PW were in very good metabolic control at time of sampling. The variations reported suggest an easier membrane lipoperoxidability and, consequently, an easier membrane damage during diabetic gestation.