Plasma bilirubin level and oxidative stress in preterm infants.
OBJECTIVE
To assess the hypothesis that changes in plasma total bilirubin levels (Btot) can influence the antioxidant system and oxidative stress in preterm infants.


METHODS
Twenty two healthy preterm infants who presented with visible non-haemolytic hyperbilirubinaemia were studied at the mean (SD) age of 3.7 (1.5) days. Btot, plasma total hydroperoxide concentration (TH), plasma protein SH group concentration, and total antioxidant capacity of the plasma (TAC) were measured at study entry and after 24 hours.


RESULTS
Btot did not correlate with TH, TAC, or protein SH group concentration, but a significant correlation was found between TH and TAC, TH and protein SH groups, and TAC and protein SH groups, both at study entry and after 24 hours.


CONCLUSIONS
The decrease in plasma bilirubin was contemporary with an increase in plasma antioxidant capacity and decrease in oxidative stress in preterm infants. This may be the result of the pro-oxidant effect of haem oxygenase, mediated by iron release, which may outcompete the antioxidant properties of bilirubin.
Dani
C
C
Division of Neonatology, Careggi University Hospital of Florence, Florence, Italy. dani@cesit1.unifi.it
Martelli
E
E
Bertini
G
G
Pezzati
M
M
Filippi
L
L
Rossetti
M
M
Rizzuti
G
G
Rubaltelli
F F
FF
D000975:Antioxidants / Q000378:metabolism; D001663:Bilirubin / Q000097:blood*; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood; D006932:Hyperbilirubinemia / Q000097:blood*; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood*; D008297:Male; D018384:Oxidative Stress
D000975:Antioxidants; D006861:Hydrogen Peroxide; D001663:Bilirubin