Delivery as a "physiological stress" and its influence on some parameters of oxidative stress.

OBJECTIVES: In healthy term newborns (HTN) to determine on the 1st and 5th day of life the activity of total antioxidant capacity (TAS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) and to compare the values with the group of asphyxiated term newborns (ATN).

PATIENTS/METHODS: The series consisted of 15 HTN and 24 ATN. In both groups TAS, MDA, GPX and SOD were investigated.

RESULTS: Reference values in HTN (1st/5th day of life) for TAS were 0.52+/-0.03/0.49+/-0.04 mmol/l, for MDA 0.72+/-0.07/1.08+/-0.09 micromol/l, for SOD 594.20+/-16.47/591.23+/-14.14 Ug/Hb and for GPX 25.48+/-1.32/25.98+/-1.20 Ug/Hb. In a group of ATN the obtained values were (1st/5th day of life): TAS 1.1+/-0.08/0.98+/-0.08 mmol/l, MDA 2.08+/-0.22/2.21+/-0.34 micromol/l, SOD 509.18+/-26.8/564.49+/-36.4 Ug/Hb and GPX 30.2+/-1.9/32.45+/-2.69 Ug/Hb.

CONCLUSIONS: Statistically significant differences were found on the 1st and 5th day of life between the two groups investigated in values of MDA (**p<0.01) and TAS (**p<0.01). Increased values of MDA in the group of ATN on the 1st and 5th day of life confirmed the presence of lipoperoxidation. The obtained values of TAS on the 1st and 5th day of life in the group of ATN were surprisingly higher than in HTN. The increase of TAS in ATN could point to a certain ability of ATN to prevent the damage of balance between overproduction of MDA and antioxidants. The results of SOD and GPX activity were not statistically significant, yet they are indicative of the biochemical reaction of the organism of term newborns to asphyxia.