Discordant Extracellular Superoxide Dismutase Expression and Activity in Neonatal Hyperoxic Lung
| Autor: | Brenda-Louise Giles, Hagir B. Suliman, Claude A. Piantadosi, Lisa B. Mamo, Eva Nozik-Grayck, Richard L. Auten |
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| Rok vydání: | 2004 |
| Předmět: |
Pulmonary and Respiratory Medicine
Hyperoxia Biology Lung injury Critical Care and Intensive Care Medicine Rats Sprague-Dawley Superoxide dismutase Andrology chemistry.chemical_compound Reference Values Intensive care Extracellular medicine Animals Lung Superoxide Dismutase Superoxide Nitrotyrosine respiratory system Rats respiratory tract diseases Oxygen medicine.anatomical_structure Animals Newborn chemistry Immunology biology.protein medicine.symptom Oxidation-Reduction |
| Zdroj: | American Journal of Respiratory and Critical Care Medicine. 170:313-318 |
| ISSN: | 1535-4970 1073-449X |
| DOI: | 10.1164/rccm.200309-1282oc |
| Popis: | Antioxidant defenses in the neonatal lung are required to adapt to the oxygen (O(2))-rich postnatal environment, and oxidant/antioxidant imbalance is a predisposition to lung injury when high concentrations of inspired O(2) are used in neonatal lung diseases. The lung's main extracellular enzymatic defense against superoxide, extracellular superoxide dismutase (EC-SOD), is closely regulated during development. In testing the hypothesis that developmental change in EC-SOD expression and activity in the immature lung would be disrupted by hyperoxia, we found a doubling of lung EC-SOD protein in newborn rats exposed to 95% O(2) for 1 week. Furthermore, EC-SOD protein secretion increased, but EC-SOD enzyme activity did not change with O(2) exposure. EC-SOD mRNA did not change at multiple points between 6 hours and 8 days. Lung EC-SOD recovered by immunoprecipitation after 1 week of O(2) showed strong increases in protein nitrotyrosine and variable, nonsignificant differences in protein carbonyl content. These data provide the first direct evidence that EC-SOD is itself a target of nitration in hyperoxia, and offer a plausible explanation for low EC-SOD activity despite its increased secretion by O(2)-exposed neonatal lung. |
| Databáze: | OpenAIRE |
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