Ginter E, Chorvatovicová D, Kosinová A
Research Institute of Human Nutrition, Bratislava, Czechoslovakia.
Int J Vitam Nutr Res. 1989;59(2):161-6.
The mutagenic effect of intraperitoneally injected K2Cr2O7 was significantly higher in vitamin C-deficient guinea pigs than in animals fed diet with high vitamin C content. Mutagenic and toxic effects of hexavalent chromium were more expressed in vitamin C-deficient guinea pigs administered K2Cr2O7 in drinking water: the number of micronuclei in polychromatic erythrocytes of bone marrow was increased, and the activity of O-demethylase and the levels of cytochromes P-450 and b5 in liver microsomes were decreased. In guinea pigs fed high vitamin C diet the same doses of bichromate in drinking water evoked no mutagenic changes in the bone marrow and no changes in microsomal enzymes in the liver. These results indicate that high intake of ascorbic acid in the diet reduces mutagenic effects of K2Cr2O7 and its toxic influence on drug metabolizing enzymes in hepatocytes. The protective effect ascorbic acid consists most probably in the enhanced extracellular and intracellular reduction of hexavalent chromium to the less toxic and less mutagenic trivalent chromium.
腹腔注射重铬酸钾（K2Cr2O7）对缺乏维生素C的豚鼠的诱变作用明显高于喂食高维生素C含量日粮的动物。在饮用水中给予重铬酸钾的缺乏维生素C的豚鼠中，六价铬的诱变和毒性作用更为明显：骨髓中多染红细胞的微核数量增加，肝脏微粒体中O-脱甲基酶的活性以及细胞色素P-450和b5的水平降低。在喂食高维生素C日粮的豚鼠中，饮用水中相同剂量的重铬酸盐未引起骨髓中的诱变变化，也未引起肝脏微粒体酶的变化。这些结果表明，日粮中高摄入量的抗坏血酸可降低重铬酸钾的诱变作用及其对肝细胞中药物代谢酶的毒性影响。抗坏血酸的保护作用很可能在于增强了细胞外和细胞内六价铬向毒性较小和诱变作用较小的三价铬的还原。
