Response of antioxidant enzymes to intermittent and continuous hyperbaric O sub 2

Conference · Mon Feb 26 04:00:00 EST 1990 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:6054321

Harabin, A L; Braisted, J C; Flynn, E T ^[1]

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1. Naval Medical Research Inst., Bethesda, MD (United States)

Rats and guinea pigs were exposed to 2.8 ATA O{sub 2} (HBO) delivered either continuously or intermittently (repeated cycles of 10 minutes 100% O{sub 2}:2.5 minutes air). The O{sub 2} time required to produce convulsions and death was increased significantly in both species by intermittency. To determine whether changes in brain and lung superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSHPx) correlated with the observed tolerance, enzyme activities were measured after short or long HBO exposures. For each exposure duration, one group received continuous and one intermittent HBO; O{sub 2} times were matched. HBO had marked effects on these enzymes: Lung SOD increased (guinea pigs 47%, rats 88%), CAT and GSHPx activities decreased (33%) in brain and lung. No differences were seen in lung GSHPx or brain CAT in rats or brain SOD of either species. In guinea pigs, but less so in rats, the observed changes in activity were usually modulated by intermittency. Increases in hematocrit, organ protein, and lung DNA, which may also reflect ongoing oxidative damage, were also slowed with intermittency in guinea pigs. Intermittency benefitted both species by postponing gross symptoms of toxicity, but its modulation of changes in enzyme activities and other biochemical variables was more pronounced in guinea pigs than in rats suggesting additional mechanisms for tolerance.

• OSTI ID: 6054321
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 4:3
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CATALASE
CENTRAL NERVOUS SYSTEM
COMPARATIVE EVALUATIONS
DNA
ELEMENTS
ENZYME ACTIVITY
ENZYMES
EVALUATION
GUINEA PIGS
KINETICS
LUNGS
MAMMALS
NERVOUS SYSTEM
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
OXYGEN
PEROXIDASES
PROTEINS
RATS
REACTION KINETICS
RESPIRATORY SYSTEM
RODENTS
SUPEROXIDE DISMUTASE
TOLERANCE
TOXICITY
VERTEBRATES