[Effects of fetal anoxia and acidosis on superoxide dismutase]

To analyze the effects of fetal anoxia, respiratory and metabolic acidosis on the activity of antioxidation in fetal distress.

Blood samples were taken from umbilical artery in 386 neonates for blood gas analysis and detection of the concentration of superoxide dismutase (SOD). Normal situation, anoxia, acidosis, respiratory acidosis, metabolic acidosis and mixed acidosis were diagnosed in all neonates according to the results of blood gas values, and the neonate asphyxia was diagnosed according to the Apgar scores (one minute). The effect of anoxia and acidosis to SOD were analyzed with multiple factor analysis of variation.

(1) Among the all 386 cases, 317 were normal, 31 with anoxia, 17 with acidosis, and 21 with both anoxia and acidosis. Among the total cases of acidosis, 8 respiratory, 21 metabolic, and 9 mixed acidosis. (2) The plasma levels of SOD of umbilical artery blood in anoxia, acidosis, both anoxia and acidosis, and normal sitution were (118.5 +/- 7.1) mmol/L, (122.0 +/- 11.4) mmol/L, (140.0 +/- 7.0) mmol/L, and (98.5 +/- 2.6) mmol/L, respectively. The results of unvariate analysis of variance showed that anoxia: F = 4.999 (P < 0.05), acidosis: F = 7.025 (P < 0.01), and both anoxia and acidosis: F = 0.013 (P > 0.05). (3) The plasma levels of SOD with respiratory acidosis, metabolic acidosis and mixed acidosis were (127.3 +/- 18.4) mmol/L, (126.0 +/- 8.1) mmol/L, (150.0 +/- 10.4) mmol/L. The results of univariate analysis of variance showed that respiratory acidosis: F = 4.404 (P < 0.05), metabolic acidosis: F = 3.965 (P < 0.05), and mixed acidosis: F = 0.015 (P > 0.05).

The superoxidation and antioxidation can be effected by factors like anoxia and acidosis, respiratory acidosis and metabolic acidosis. However, the mechanisms of these effects are different. There is additive, but not synergistic effects among them.