An age-related difference in hyperoxia lethality: role of lung antioxidant defense mechanisms.

Published

Journal Article

The role of animal age in the lethal response to > 98% oxygen has been extensively studied, with the observation that neonatal rats were resistant while mature animals were sensitive. Antioxidant enzymes increased during the oxygen exposure in neonatal but not in mature rats, suggesting they were important in the age-related toxicity difference. Because no studies had compared the response of mature and old rats to hyperoxia, we exposed Fischer 344 rats, aged 2 and 27 mo, to > 98% oxygen. Unexpectedly, the old rats lived significantly longer than young, 114 and 65 h, respectively. No histopathological differences were found to explain the results. Of the antioxidants, only glutathione peroxidase (GPx) activity was higher in the lungs of nonexposed old rats. Superoxide dismutase (SOD) was higher in the young, results opposite those expected if SOD was important in the lethality difference. No antioxidant induction occurred in the old oxygen-exposed rats. These results suggest that although there may be a role for GPx, mechanisms in addition to antioxidant protection and inflammation are likely responsible for the age-related difference in hyperoxia lethality.

Full Text

Duke Authors

Cited Authors

  • Canada, AT; Herman, LA; Young, SL

Published Date

  • April 1995

Published In

Volume / Issue

  • 268 / 4 Pt 1

Start / End Page

  • L539 - L545

PubMed ID

  • 7733296

Pubmed Central ID

  • 7733296

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajplung.1995.268.4.L539

Language

  • eng

Conference Location

  • United States