Metabolism of the carcinogen chromate by cellular constituents

摘要: The redox chemistry of chromium(VI) is discussed with respect to the cellular metabolism carcinogen chromate in vivo. Possible sites for reduction chromium(III) are considered. reactions amino acids, ascorbic acid, carboxylic thiol-containing mole-cules and other small molecules under physiological conditions presented. In general only ascorbate those containing sulfhydryl groups capable easily reducing at pH 7.4. Thus, cytoplasm, glutathione, cysteine likely candidates react chromate. While most proteins unreactive toward chromate, certain active heme hemoglobin cytochrome P-450 possess chromate-reductase activity, whereas c myoglobin inactive. NADPH-dependent flavoenzymes glutathione reductase NADPH-cytochrome also activity. However, NAD(P)H enzymes, isocitrate dehydrogenase, glutamate dehyrogenase malate dehydrogenase do not reduce Both microsomes mitochondria microsomal activity accounted by reductase/cytochrome system. enzyme(s) responsible mitochondrial have been identified. Chromium(VI) its metabolite inhibit normal activities enzymes which bind or involves generation reactive intermediates ultimately constituents damage their function cell.