LIPID-PEROXIDATION AND SUPEROXIDE-DISMUTASE ACTIVITY IN UMBILICAL ANDMATERNAL BLOOD

Oxygenation of both mother and child tissues oscillate frequently duri ng labour. We tested the lipid peroxidation caused by reactive oxygen species which are produced in consequence of tissue reoxygenation and the inactivation of these species by the maternal. and newborn superox ide dismutase. Total malondialdehyde in concentrations (x +/- SE) of 1 .04 +/- 0.17, 1.57 +/- 0.22, 1.33 +/- 0.14 and 1.36 +/- 0.21 mu mol/L was found in maternal plasma and red blood cells and newborn plasma an d red blood cells, respectively, after uncomplicated deliveries and 4. 93 +/- 1.34, 7.12 +/- 1.37, 4.77 +/- 1.29 and 7.37 +/- 1.51 mu mol/L, respectively, after deliveries with clinical signs of foetal. hypoxia. In newborns, erythrocyte superoxide dismutase activity reached only 8 2% of the maternal level (p<0.05). The results indicate that the mater nal and foetal antioxidant defence systems can be overloaded during de liveries with abnormal oxygenation, where increased lipid peroxidation occurred.