Glutathione synthetic activity in the lungs in newborn guinea pigs.
Depletion of glutathione, a key antioxidant, accelerates lung injury. Glutathione concentrations are reduced significantly in premature infants with respiratory distress syndrome, leaving them at greater risk of bronchopulmonary dysplasia. A study was designed to verify if the increased glutathione synthetic activity observed in oxygen-dependent and ventilated newborn infants was caused by their postsurgical state. Our objective was to evaluate the role of a general surgical procedure as a factor affecting lung glutathione. One-day-old guinea pig pups, a well characterized animal model for the study of neonatal lung disease, were divided between those undergoing a standardized surgical procedure and those that did not. The pups were fed by their mother. After 4 days the lungs were sampled to determine total glutathione content, activities of gamma-glutamyltranspeptidase, glutathione peroxidase, and reductase as well as the glutathione synthetic activity. The surgical procedure was associated with a specific stimulatory effect limited to glutathione synthetic activity (p < 0.02) leading to an increased (p < 0.02) pulmonary glutathione content. Glutathione concentration was significantly correlated (r2 = 0.67) with the synthetic activity. We concluded that in this animal model an invasive procedure such as a general surgical procedure affects lung glutathione metabolism in a fashion similar to that of hyperoxia. In the lungs, the synthetic activity is a stronger determinant of glutathione concentrations than the activities of the other enzymes involved in maintaining glutathione levels.
Lavoie
J C
JC
Department of Pediatrics and Research Center Hospital Ste-Justine, University of Montréal, 3175 Chemin Côte Sainte-Catherine, Montréal, Québec H3T 1C5, Canada.
Spalinger
M
M
Chessex
P
P
D000818:Animals; D000831:Animals, Newborn; D001997:Bronchopulmonary Dysplasia / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis* / Q000502:physiology; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000378:metabolism* / Q000601:surgery; D012121:Respiration, Artificial; D012127:Respiratory Distress Syndrome, Newborn / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005723:gamma-Glutamyltransferase; D005978:Glutathione