Abstract
The cytotoxic effects of many quinones are thought to be mediated through their one-electron reduction to semiquinone radicals, which subsequently enter redox cycles with molecular oxygen to produce active oxygen species and oxidative stress. The two-electron reduction of quinones to diols, mediated by DT-diaphorase (NAD(P)H: (quinone-acceptor) oxidoreductase), may therefore represent a detoxifying pathway which protects the cell from the formation of these reactive intermediates. By using menadione (2-methyl-1,4-naphthoquinone) and isolated hepatocytes, the relative contribution of the two pathways to quinone metabolism has been studied and a protective role for DT-diaphorase demonstrated. Moreover, in the presence of cytotoxic concentrations of menadione rapid changes in intracellular thiol and Ca 2+ homeostasis were observed. These were associated with alterations in the surface structure of the haptocytes which may be an early indication of cytotoxicity.
Lingua originale | Inglese |
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pagine (da-a) | 12419-12425 |
Numero di pagine | 7 |
Rivista | Journal of Biological Chemistry |
Volume | 257 |
Numero di pubblicazione | 20 |
Stato di pubblicazione | Pubblicato - 1982 |
Pubblicato esternamente | Sì |