Enzyme-controlled scavenging of ascorbyl and 2,6-dimethoxy-semiquinone free radicals in Ehrlich ascites tumor cells.
- 1 March 1985
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 82 (5) , 1439-1442
- https://doi.org/10.1073/pnas.82.5.1439
Abstract
The rate of scavenging by Ehrlich ascites cells of anionic ascorbyl and 2.6-dimethoxy-p-semiquinone free radicals was investigated by ESR 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 SH group. Attempts to identify the enzyme with the repoted properties of either semi-dehydroascorbate reductase or DT-diaphorase were not successful. The overall free-radical scavenging activity for viable cells is dextrose dependent and is controlled by the coulombic barrier associated with the cell-sruface 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.This publication has 8 references indexed in Scilit:
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