DEVELOPMENT OF GLUTATHIONE SYNTHESIS AND GAMMA-GLUTAMYL-TRANSPEPTIDASE ACTIVITIES IN TISSUES FROM NEWBORN-INFANTS

Following the observation that the level of glutathione in leukocytes from human newborn infants was lower in preterm and in male infants, a study was designed to document the level of activities of glutathione synthesis and gamma-glutamyltranspeptidase during the development of preterm and term newborn infants. Measurements were performed in leuko cytes from tracheal aspirates of oxygen dependent infants, and in leuk ocytes from cord blood. Contrary to the common belief concerning the d evelopment of antioxidant activity, the biosynthesis of glutathione wa s active in leukocytes from preterm infants; and by two days of life t he activity of gamma-glutamyltranspeptidase reached 3 times the level of that seen in cord blood. Our results suggest that the maturity of t hese enzymes was not the limiting step in maintaining cellular glutath ione levels. This represents new information concerning the maturation of a central antioxidant in tissue derived from preterm and term huma n newborn infants at risk of oxidant stress. This implies that sources of cysteine crossing freely the cellular membrane could be used by ti ssues of term and preterm infants to produce glutathione. (C) 1998 Els evier Science Inc.