title: Glutathione recycling and antioxidant enzyme activities in erythrocytes of term and preterm newborns at birth.
abstract: We previously demonstrated a high susceptibility of neonatal red blood cells (RBC) to oxidative stress at birth. The aim of this study was to compare the RBC antioxidant capacity and redox cycle enzyme activities as well as glutathione (GSH) recycling in full-term and preterm infants at birth and in normal adults. GSH and GSH disulfide (GSSG) concentrations, GSH/GSSG ratio, and the activities of glucose-6-phosphate dehydrogenase (G-6-PDH), GSH peroxidase, GSH reductase (GR), catalase (CAT), superoxide dismutase (SOD), and hexokinase (HK) were measured in RBC of 25 healthy adults and 56 newborns (23 term, 33 preterm) at birth. The GSH recycling was measured in adult and newborn RBC exposed to oxidative stress (1 mM tert-butylhydroperoxide). The RBC of term and preterm babies showed higher GSH, GSSG, G-6-PDH, GR, and HK levels/activities and lower GSH/GSSG ratios and higher GSH-recycling rates than those of adults. In preterm babies significant correlations were found between G-6-PDH and CAT, GSH, GSH/GSSG ratio, and GSSG (r = -0.67, r = 0.71, r = -0.66, p < 0.01; r = 0.71, p < 0.05, respectively). In term newborns, statistically significant correlations were observed between G-6-PDH and CAT, SOD, and GSH (r = -0.65, r = -0.65, r = -0.69, p < 0.01, respectively). The results indicate the central role of the G-6-PDH activity in antioxidant defenses. We speculate that preterm babies have prompter involvement of antioxidant defenses than term babies.
authors.affiliation: Department of Neuroscience, Pharmacology Unit, University of Siena, Siena, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Frosali
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Simplicio
authors.forename: Serafina
authors.initials: S
authors.lastname: Perrone
authors.forename: Danila
authors.initials: D
authors.lastname: Di Giuseppe
authors.forename: Mariangela
authors.initials: M
authors.lastname: Longini
authors.forename: Donatella
authors.initials: D
authors.lastname: Tanganelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Buonocore
mesh_terms: D000328:Adult; D002374:Catalase / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology* / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D005978:Glutathione / Q000097:blood*; D019803:Glutathione Disulfide / Q000097:blood*; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D006593:Hexokinase / Q000097:blood; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D007234:Infant, Premature / Q000097:blood*; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D006593:Hexokinase; D005978:Glutathione; D019803:Glutathione Disulfide