Document Detail

Enzyme-controlled scavenging of ascorbyl and 2,6-dimethoxy-semiquinone free radicals in Ehrlich ascites tumor cells.
MedLine Citation:
PMID:  3856273     Owner:  NLM     Status:  MEDLINE    
The rate of scavenging by Ehrlich ascites cells of anionic ascorbyl and 2,6-dimethoxy-p-semiquinone free radicals has been investigated by electron spin resonance spectroscopy both for viable cells and for subcellular fractions obtained by differential centrifugation. The scavenging activity is concluded to be associated with an NAD(P)H enzyme containing an active sulfhydryl group. Attempts to identify the enzyme with the reported properties of either semi-dehydro-ascorbate reductase or DT-diaphorase have not been successful. The overall free-radical scavenging activity for viable cells is dextrose dependent and is controlled by the coulombic barrier associated with the cell-surface charge. The cytotoxicity of the mixture of ascorbic acid with 2,6-dimethoxy-p-benzoquinone is concluded to result from a loss of NAD(P)H reducing power in the cells.
R Pethig; P R Gascoyne; J A McLaughlin; A Szent-Györgyi
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  82     ISSN:  0027-8424     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  1985 Mar 
Date Detail:
Created Date:  1985-04-08     Completed Date:  1985-04-08     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1439-42     Citation Subset:  IM    
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MeSH Terms
Ascorbic Acid / metabolism*
Carcinoma, Ehrlich Tumor / physiopathology*
Free Radicals*
Magnetic Resonance Spectroscopy
NAD / metabolism
Quinones / metabolism*
Sulfhydryl Compounds / metabolism
Surface Properties
Reg. No./Substance:
0/Benzoquinones; 0/Free Radicals; 0/Quinones; 0/Sulfhydryl Compounds; 26547-64-8/2,6-dimethoxysemiquinone radicals; 50-81-7/Ascorbic Acid; 53-84-9/NAD

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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