title: Decreased oxidative metabolism in neonatal rat lung exposed to hyperoxia.
abstract: The effect of exposure to high O2 concentration on neonatal rat lung oxidative function was determined. The water content of lungs from neonatal rats exposed to 100% O2 for the first 6 days of life was 3% greater than room-air control, indicating minimal pulmonary edema. Since neonatal rat lungs exposed to O2 have minimal pulmonary edema, they provide a model to determine the direct effect of O2 on mitochondrial oxidative function. After 6 days of exposure to 100% O2, lactate production by lung slices of neonatal rats was twofold greater than room-air controls. Lactate production by lung slices of neonatal rats exposed to six days of O2 and then 3 days of room air was equal to controls. Total pyruvate dehydrogenase activity was 45% lower in O2-exposed lung compared with control, and active pyruvate dehydrogenase activity was 20% lower. The oxidation of lauric acid, acetate, and beta-hydroxybutyrate was 40% lower in the O2-exposed lung compared with controls. These data suggest that there is a toxic effect of O2 on mitochondrial oxidative function in the absence of severe pulmonary edema and that these toxic effects are reversible within 72 h.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*; D011773:Pyruvates / Q000378:metabolism; D051381:Rats / Q000378:metabolism*; D011919:Rats, Inbred Strains
chemical_list: D011773:Pyruvates; D005947:Glucose; D010100:Oxygen