Original Paper

Oxidative Challenge and Glucose-6-Phosphate Dehydrogenase Activity of Preterm and Term Neonatal Red Blood Cells
Chun Hay Ko, Raymond Pui-On Wong, Pak Cheung Ng, Karen Li, Kit Man Chui, Patrick Man-Pan Yuen, Tai Fai Fok

Department of Paediatrics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China

Address of Corresponding Author

Neonatology 2009;96:96-101 (DOI: 10.1159/000205720)

  Key Words

• Glucose-6-phosphate dehydrogenase
• Hyperbilirubinemia
• Glutathione, reduced
• Oxidative stress

  Abstract

Background: Recent studies suggest that a low antioxidant level in preterm infants may predispose them to increased oxidative stress and results in hyperbilirubinemia, whereas glucose-6-phosphate dehydrogenase (G6PD) activity was found to be higher in preterm infants than in term infants. Objectives: To evaluate (1) the oxidative effect of -naphthol on preterm and term red blood cells, and (2) the relationship between G6PD activity and the gestational age of these infants. Methods: G6PD activities were determined in preterm and term infants by a standard diagnostic method. Whole blood samples were incubated with -naphthol for 2 h and their pre- and post-challenged reduced glutathione (GSH) levels were quantified. Results: The mean G6PD activity in preterm infants (n = 113; 13.52 ± 0.19 U/g Hb; gestational age 30.67 ± 0.28 weeks) was significantly higher than that in term infants (n = 100; 12.36 ± 0.16 U/g Hb; gestational age 39.82 ± 0.14 weeks; p < 0.001). A significantly negative correlation was demonstrated between gestational age and G6PD activity (r = -0.34, p < 0.001). GSH levels of preterm and term subjects were similar at baseline, but were significantly decreased upon challenge with -naphthol (p < 0.001). The percentage reduction in GSH levels was similar in the various gestational age groups. Conclusions: Our data show that G6PD activities had a negative correlation with gestational age of G6PD-normal infants. The similar response of preterm and term erythrocytes to an -naphthol challenge indicates the manifestation of an active anti-oxidative pathway mediated by cellular GSH.

Copyright © 2009 S. Karger AG, Basel

  Author Contacts

Tai Fai Fok, MD
Department of Paediatrics, Prince of Wales Hospital
Chinese University of Hong Kong
Shatin, NT, Hong Kong, SAR (China)
Tel. +852 2632 2850, Fax +852 2636 0020, E-Mail taifaifok@cuhk.edu.hk

  Article Information

Received: October 25, 2007
Accepted after revision: July 24, 2008
Published online: March 4, 2009
Number of Print Pages : 6
Number of Figures : 4, Number of Tables : 1, Number of References : 36