title: Glutathione synthesis rates in early postnatal life.
abstract: Preterm infants have diminished antioxidant defenses. Glutathione (GSH), the main intracellular antioxidant, increases upon amino acid (AA) administration in preterm infants, without an accompanying rise of the fractional synthesis rate of GSH (FSRGSH) This study investigated the mechanism behind this increased GSH concentration by determining GSH synthesis in the first days after birth using stable isotope techniques in very low-birth-weight (VLBW) infants receiving i.v. AAs. Advanced oxidized protein products (AOPPs) were determined to quantify oxidative stress. Eighteen infants (birth weight 989 +/- 241 g, gestational age of 27/7 +/- 1/7 weeks) were studied either on postnatal day 1 or 2 (7 or 31 h postnatally, respectively). Concentration of GSH increased with postnatal age (1.45 +/- 0.48 mM versus 1.99 +/- 0.40 mM, p = 0.019). FSRGSH was not significantly different, but the absolute synthesis rate of GSH (ASRGSH) tended to be higher in the infants studied on day 2 [8.1 +/- 2.7 mg/(kg . d) versus 10.6 +/- 2.4 mg/(kg . d), p = 0.054]. AOPP concentrations were not different between groups. In conclusion, GSH concentration in VLBW infants increases significantly after birth. A concomitant increased synthesis rate was not found, suggesting that GSH consumption decreases upon AA administration.
authors.affiliation: Department of Pediatrics, Erasmus MC-Sophia Children's Hospital, 3015 GJ Rotterdam, The Netherlands.
authors.forename: Denise
authors.initials: D
authors.lastname: Rook
authors.forename: Frans W J
authors.initials: FW
authors.lastname: Te Braake
authors.forename: Henk
authors.initials: H
authors.lastname: Schierbeek
authors.forename: Mariangela
authors.initials: M
authors.lastname: Longini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Buonocore
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Van Goudoever
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism*; D001724:Birth Weight; D002149:Energy Intake; D005260:Female; D005865:Gestational Age; D005978:Glutathione / Q000096:biosynthesis*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D019102:Infant, Very Low Birth Weight / Q000378:metabolism*; D008297:Male; D009752:Nutritional Status; D010084:Oxidation-Reduction; D018384:Oxidative Stress
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D005978:Glutathione