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Updated: Dec 17, 2025
Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Relationship Between Oxidative Stress Markers and Endothelin-1 Levels in Newborns of Different Gestational Ages
Gospodin Stefanov1, Seema Briyal2, Gwendolyn Pais2
1Division of Neonatology, Advocate Children's Hospital, Park Ridge, IL, United States.
Insights
Oxidative stress markers like malondialdehyde (MDA) and Endothelin-1 (ET-1) are higher in cord blood than at 24 hours of life in newborns. These markers appear to act independently, especially in preterm infants.
Area of Science:
- Neonatal physiology
- Biochemistry
- Perinatal medicine
Background:
- Oxidative stress, caused by an imbalance between reactive oxygen species and antioxidant defenses, poses a significant risk to newborns, particularly preterm infants with immature antioxidant systems.
- Endothelial dysfunction and alterations in Endothelin-1 (ET-1) signaling are linked to oxidative stress, but their combined effects in neonates remain unclear.
- Understanding the interplay between oxidative stress and ET-1 is crucial for managing neonatal health outcomes.
Purpose of the Study:
- To investigate the relationship between oxidative stress biomarkers (glutathione and malondialdehyde) and Endothelin-1 (ET-1) levels in newborns across different gestational ages.
- To compare these biomarker levels in umbilical cord blood versus blood drawn 24 hours after birth.
- To explore potential influencing factors such as prenatal corticosteroid exposure and oxygen therapy.
Main Methods:
- Prospective enrollment of 63 neonates in a Level IV NICU, categorized by gestational age: Early Preterm, Late Preterm, and Term.
- Collection of umbilical cord and 24-hour blood samples for analysis of glutathione (GSH), malondialdehyde (MDA), and ET-1 using established methodologies.
- Statistical analysis to determine correlations and significant differences between groups and time points.
Main Results:
- Malondialdehyde (MDA) levels were significantly higher in cord blood compared to 24-hour samples across all gestational age groups (p < 0.001).
- Endothelin-1 (ET-1) levels were significantly higher in cord blood than at 24 hours in Early and Late Preterm neonates (p < 0.05).
- No significant correlation was found between ET-1 and MDA or GSH levels at either time point.
- Prenatal corticosteroid exposure was associated with lower cord MDA levels, while oxygen therapy correlated with higher oxidative stress markers.
Conclusions:
- Oxidative stress markers (MDA) and ET-1 levels appear to operate independently in the neonatal period.
- MDA levels are elevated at birth and decrease by 24 hours of life, irrespective of gestational age.
- Preterm neonates exhibit higher ET-1 levels in cord blood compared to later time points, suggesting a potential role in preterm infant physiology.
Abstract:
Oxidative stress results from excessive reactive oxygen species formation and/or inadequate antioxidant defense. Premature and critically ill infants are especially susceptible due to an immature intrinsic antioxidant system that cannot fully compensate for a free radical load. Oxidative stress is also associated with endothelial dysfunction and alterations in Endothelin-1 (ET-1) signaling pathways. However, the effects of the complex interaction between oxidative stress and ET-1 in newborns are not well-understood. The objective of this pilot study was to determine the relationship between levels of common oxidative stress biomarkers [glutathione (GSH), malondialdehyde (MDA)] and ET-1 in newborns of different gestational ages. In a level IV NICU, 63 neonates were prospectively enrolled and divided into groups based on gestational age at birth: Early Preterm (24 0/7-30 6/7 weeks), Late Preterm (31 0/7-36 6/7 weeks), and Term (37 0/7-42 weeks). Umbilical cord (1.5 mL) and 24(±4) h of life (24 h) (1 mL) blood samples were collected for GSH, MDA, and ET-1 analyses. GSH, MDA, and ET-1 were determined using established methodology. Mean cord MDA levels for all age groups, Early Preterm (2.93 ± 0.08 pg/ml), Late Preterm (2.73 ± 0.15 pg/ml), and Term (2.92 ± 0.13 pg/ml), were significantly higher than those at 24 h of life (p < 0.001). Mean cord ET-1 levels were significantly higher than 24 h samples in both Early and Late Preterm groups (p < 0.05). Cord and 24 h ET-1 levels did not correlate with MDA and GSH levels at birth (r2 = 0.03, p > 0.05 and r2 = 0.001, p > 0.05, respectively) or 24 h of life (r2 = 0.001, p > 0.05 and r2 = 0.03, p > 0.05, respectively). Preterm neonates exposed to prenatal corticosteroids (1.87 ± 0.31 pg/ml) had lower cord MDA levels than non-exposed neonates (2.85 ± 0.12 pg/ml) (p < 0.05). Both cord and 24 h OS markers were significantly higher in neonates treated with oxygen therapy (p < 0.005 and p < 0.05, respectively) than those who did not receive supplemental oxygen. Oxidative stress markers (MDA and GSH) and ET-1 levels act independently. MDA is higher in cord blood than at 24 h of life regardless of gestational age. In preterm neonates, ET-1 levels are higher in umbilical cord blood compared to 24 h of life.
