抄録
As the nutritional status of an individual is important in the regulation of xenobiotic metabolism brought about by the activation and detoxification enzymes of mixed function oxidase systems, the balance of these reactions ultimately determines the fate of xenobiotic agents and thereby modulates their toxic, mutagenic, and carcinogenic effects. Among the dietary factors vitamin C has attracted special attention because of its non-toxic nature and tumor prophylactic effects on a number of experimentally induced tumors. In this study we evaluated the effect of N-nitrosodiethylamine (NDEA), a potent environmental carcinogen, on the status of the Ah-receptor (involved in the induction of arylhydrocarbon hydroxylase) in guinea pigs fed excessive doses of ascorbic acid. The Ah-receptor was estimated by two methods, hydroxylapatite assay and Sephacryl S-300 column chromatography. We found that in both the assays the level of Ah-receptors was significantly decreased in excessive ascorbic acid-fed guinea pigs treated with NDEA. The hydroxylapatite method, which was more convenient, fast and economical is to be preferred for the assay of the Ah-receptor.
