Xanthine dehydrogenase to xanthine oxidase conversion in ischemic rat intestine

Conference · Sun Feb 25 23:00:00 EST 1990 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:6006932

McKelvey, T G; Engerson, T D; Elmore, C R; Jones, H P ^[1]

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1. Univ. of South Alabama, Mobile (United States)

The ischemic conversion of the NADH-producing xanthine dehydrogenase (XDH) to an oxidase form, that produces both superoxide radical and hydrogen peroxide, has been proposed as an important step in initiating oxygen radical-mediated ischemia-reperfusion injury. It has also been reported that two forms of converted oxidase are produced in ischemic rat liver; a reversible xanthine oxidase produced through sulfhydryl oxidation, that can be reconverted to XDH by incubation with 10mM dithiothreitol (Dtt) at 37{degrees}C, and a Dtt-irreversible oxidase produced via proteolysis. The authors report that increased oxidase in the ischemic rat intestine results from significant increases in both the Dtt-reversible and Dtt-irreversible forms of xanthine oxidase. Total oxidase activity (Irreversible + Dtt-reversible) was 19% of the total enzyme activity (XDH + XO) in control ileum and distal jejunum, increased to 26% after 1 hour of ischemia at 37{degrees}C, and significantly to 36% after 1.5 hours. After 3 hours 73% of the activity was in the oxidase form. Irreversible oxidase comprised 15% of the total activity in control intestine, significantly increased to 25% after 2 hours, and further to 42% after 3 hours. Dtt-reversible oxidase was 3% of the total activity in controls, increased to 13% after 1.5 hours, and significantly to 29% after 2 hours.

• OSTI ID: 6006932
• Report Number(s): CONF-9104107--
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Vol. 4:3; ISSN FAJOE; ISSN 0892-6638
• 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.
ANEMIAS
ANIMALS
AROMATICS
AZAARENES
BIOCHEMICAL REACTION KINETICS
BODY
CARDIOVASCULAR DISEASES
DIGESTIVE SYSTEM
DISEASES
ENZYMES
GASTROINTESTINAL TRACT
GLANDS
HEMIC DISEASES
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
INTESTINES
ISCHEMIA
KINETICS
LIVER
MAMMALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PATHOGENESIS
PEROXIDES
PROTEINS
PURINES
RADICALS
RATS
REACTION KINETICS
RODENTS
SUPEROXIDE RADICALS
SYMPTOMS
THIOLS
VASCULAR DISEASES
VERTEBRATES
XANTHINES