Adding glutathione to parenteral nutrition prevents alveolar loss in newborn Guinea pig

Bronchopulmonary dysplasia, a main complication of prematurity, is characterized by an alveolar hypoplasia. Oxidative stress is suspected to be a trigger event in this population who has a low level of glutathione, a main endogenous antioxidant, and who receives high oxidative load, particularly ascorbylperoxide from their parenteral nutrition. Hypothesis: the addition of glutathione (GSSG) in parenteral nutrition improves detoxification of ascorbylperoxide by glutathione peroxidase and therefore prevents exaggerated apoptosis and loss of alveoli. Methods: Ascorbylperoxide is assessed as substrate for glutathione peroxidase in Michaelis-Menten kinetics. Three-days old guinea pig pups were divided in 6 groups to receive, through a catheter in jugular vein, the following solutions: 1) Sham (no infusion); 2) PN(-L): parenteral nutrition protected ! against light (low ascorbylperoxide); 3) PN(+L): PN without photo-protection (high ascorbylperoxide); 4) 180 mu M ascorbylperoxicle; 5) PN(+L)+10 mu M GSSG; 6) ascorbylperoxyde +10 mu M GSSG. After 4 days, lungs were sampled and prepared for histology and biochemical determinations. Data were analysed by AN OVA. p < 0.05 Results: The Km of ascorbylperoxide for glutathione peroxidase was 126 +/- 6 mu M and Vmax was 384 +/- 2.5 nmolimini U. The presence of GSSG in intravenous solution has prevented the high GSSG, oxidized redox potential of glutathione, activation of caspase-3 (apoprosis marker) and loss of alveoli induced by PN( + L) or ascorbylperoxide. Conclusion: A correction of the low glutathione levels observed in newborn animal on parenteral nutrition, protects lungs from toxic effect of ascorbylperoxide. Premature infants having a low level of glutathione, this finding is of high importance because it provides hope in a possible prevention of bronchopulmonary dysplasia. (C) 2015 Published by Elsevier Inc.