ACTIVITY OF THE ANTIOXIDANT ENZYMES SUPEROXIDE-DISMUTASE AN GLUTATHIONE-PEROXIDASE IN FETAL ERYTHROCYTES

It is generally accepted that the balance between the formation and in activation of reactive oxygen species may be abolished within the peri natal period, as a consequence of rapid changes in tissue oxygen conce ntration and the development of antioxidant defence enzyme activities. We studied the ontogeny of the antioxidant enzymes superoxide dismuta se (SOD) and glutathione peroxidase (GPx) in fetal blood samples. The activity of SOD in fetal erythrocytes taken in the 17th gestational we ek was the same as that in erythrocytes of healthy blood donors. On th e other hand, GPx activity was significantly lower between the 17th an d 25th gestational week and at the time of delivery, compared with the healthy adult control. Our results suggest that the supposed underdev elopment of the antioxidant system in the lungs or in the other organs of premature infants cannot be monitored by SOD and GPx activities in erythrocytes, because these reach adult levels before the 17th week f or SOD and from the 26th to the 35th gestational week for GPx, with lo wer levels from the 17th to the 25th week and at term.