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. 1985 Mar;82(5):1439–1442. doi: 10.1073/pnas.82.5.1439

Enzyme-controlled scavenging of ascorbyl and 2,6-dimethoxy-semiquinone free radicals in Ehrlich ascites tumor cells.

R Pethig, P R Gascoyne, J A McLaughlin, A Szent-Györgyi
PMCID: PMC397277  PMID: 3856273

Abstract

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.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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