TNF-alpha effect on oxygen free radical scavenging and generating enzymes in rat liver.
The presence of cancer induces metabolic alterations in distant, tumor-free tissues and organs of the host. A remote humoral effect of cancer growing extrahepatically is an increase in the activity of oxidant and a decrease of antioxidant enzymes in the liver of the tumor-bearing animal. We speculated that TNF-alpha, produced by host cells, the cancer, or both, is responsible for these changes. When human recombinant TNF-alpha, 100 micrograms/kg/d i.p. for 5 days, was injected in groups of rats fed ad libitum, starved, or pair-fed, a decrease in the activity of superoxide dismutase and glutathione peroxidase and an increase in xanthine oxidase was observed, particularly with pair-fed controls. It is concluded that TNF-alpha, directly or indirectly, causes these enzyme alterations in the tumor-free liver of a tumor-bearing host.
Theologides
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Department of Medicine, University of Minnesota School of Medicine, Minneapolis 55415.
Ingersoll-Stroubos
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AM
Apple
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FS
D000704:Analysis of Variance; D000818:Animals; D016166:Free Radical Scavengers; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014969:Xanthine Oxidase / Q000378:metabolism
D016166:Free Radical Scavengers; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase