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Developmental patterns of antioxidant defense mechanisms in human erythrocytes
M J Ripalda1, N Rudolph, S L Wong
1Departmentof Pediatrics, SUNY Health Science Center, Brooklyn 11203.
Insights
Erythrocyte antioxidant defenses mature during late fetal development, with significant increases in catalase, glutathione peroxidase, and vitamin E. Glutathione S-transferase activity decreases with gestational age.
Area of Science:
- Biochemistry
- Neonatal Physiology
- Red Blood Cell Metabolism
Background:
- Erythrocyte antioxidant defense is crucial for protecting against oxidative stress.
- Understanding antioxidant potential during fetal development is important for neonatal health.
Purpose of the Study:
- To profile erythrocyte antioxidant defense potential in late fetal development.
- To assess changes in specific antioxidant enzymes and vitamin E levels with maturation.
Main Methods:
- Blood samples analyzed from 65 neonates and 12 healthy adults.
- Measured erythrocyte superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase activities.
- Quantified plasma vitamin E levels.
Main Results:
- Superoxide dismutase activity showed no significant change with maturation.
- Catalase activity, glutathione peroxidase activity, and plasma vitamin E levels positively correlated with fetal weight and gestational age.
- Glutathione S-transferase activity negatively correlated with gestational age, with lower adult levels.
Conclusions:
- Significant maturational changes in erythrocyte antioxidant parameters begin around 31-36 weeks of gestation.
- While catalase reaches adult levels by term, glutathione peroxidase and vitamin E remain lower.
- The role of glutathione S-transferase in erythrocyte metabolism requires further investigation.
Abstract:
To obtain a profile of erythrocyte antioxidant defense potential during late fetal development, we studied selected antioxidant parameters in blood samples from 65 neonates with birth wt between 520 and 4210 g and from 12 healthy adults. Erythrocyte superoxide dismutase activity did not change significantly with maturation and no significant differences were observed among preterm infants grouped in increasing birth wt categories, term neonates, and adults. Erythrocyte catalase and glutathione peroxidase, as well as plasma vitamin E levels, showed highly significant positive correlations (p less than 0.001) with increasing fetal wt and gestational age; by term, CAT activity reached a level similar to the adult control group, but glutathione peroxidase activity, as well as plasma vitamin E levels, were markedly lower in all the preterm and in the term groups than in adults (p less than 0.01). Erythrocyte glutathione S-transferase activity showed a negative correlation with increasing gestational age (p less than 0.01) and the adult values were considerably lower than any of the neonatal levels (p less than 0.001). The role of glutathione S-transferase in erythrocyte metabolism remains obscure. Maturational changes in the activity of the red cell enzymes that were studied and in the plasma vitamin E level were apparent from about 31-36 wk of gestation, suggesting that the stimulation for these changes may have commenced from about 28-31 wk.