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

Abstract

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 variablesmore » was more pronounced in guinea pigs than in rats suggesting additional mechanisms for tolerance.« less

Authors:
; ;  [1]
  1. Naval Medical Research Inst., Bethesda, MD (United States)
Publication Date:
OSTI Identifier:
6054321
Report Number(s):
CONF-9104107-
Journal ID: ISSN 0892-6638; CODEN: FAJOE
Resource Type:
Conference
Journal Name:
FASEB Journal (Federation of American Societies for Experimental Biology); (United States)
Additional Journal Information:
Journal Volume: 4:3; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; Journal ID: ISSN 0892-6638
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; CATALASE; BIOCHEMICAL REACTION KINETICS; OXIDOREDUCTASES; OXYGEN; TOXICITY; SUPEROXIDE DISMUTASE; BRAIN; COMPARATIVE EVALUATIONS; DNA; ENZYME ACTIVITY; GUINEA PIGS; LUNGS; RATS; TOLERANCE; ANIMALS; BODY; CENTRAL NERVOUS SYSTEM; ELEMENTS; ENZYMES; EVALUATION; KINETICS; MAMMALS; NERVOUS SYSTEM; NONMETALS; NUCLEIC ACIDS; ORGANIC COMPOUNDS; ORGANS; PEROXIDASES; PROTEINS; REACTION KINETICS; RESPIRATORY SYSTEM; RODENTS; VERTEBRATES; 560300* - Chemicals Metabolism & Toxicology

Citation Formats

Harabin, A L, Braisted, J C, and Flynn, E T. Response of antioxidant enzymes to intermittent and continuous hyperbaric O sub 2. United States: N. p., 1990. Web.
Harabin, A L, Braisted, J C, & Flynn, E T. Response of antioxidant enzymes to intermittent and continuous hyperbaric O sub 2. United States.
Harabin, A L, Braisted, J C, and Flynn, E T. 1990. "Response of antioxidant enzymes to intermittent and continuous hyperbaric O sub 2". United States.
@article{osti_6054321,
title = {Response of antioxidant enzymes to intermittent and continuous hyperbaric O sub 2},
author = {Harabin, A L and Braisted, J C and Flynn, E T},
abstractNote = {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.},
doi = {},
url = {https://www.osti.gov/biblio/6054321}, journal = {FASEB Journal (Federation of American Societies for Experimental Biology); (United States)},
issn = {0892-6638},
number = ,
volume = 4:3,
place = {United States},
year = {Mon Feb 26 00:00:00 EST 1990},
month = {Mon Feb 26 00:00:00 EST 1990}
}

Conference:
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