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MX [3-Chloro-4-(Dichloromethyl)-5-Hydroxy-2[5H]-Furanone], A Drinking-Water Carcinogen, Does Not Induce Mutations in the Liver of Cii Transgenic Medaka (Oryzias latipes)
Citation:
Geter, D. R., R. N. Winn, J W. Fournie, M. B. Norris, A Deangelo, AND W. E. Hawkins. MX [3-Chloro-4-(Dichloromethyl)-5-Hydroxy-2[5H]-Furanone], A Drinking-Water Carcinogen, Does Not Induce Mutations in the Liver of Cii Transgenic Medaka (Oryzias latipes). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 67(5):373-383, (2004).
Impact/Purpose:
To study the ability of MX to induce mutations in the liver of medaka, a small fish model
Description:
Mutagenicity assays with Salmonella have shown that 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX), a drinking water disinfection by-product is a potent mutagen, accounting for about one third of the mutagenic potency/potential of chlorinated drinking water. The ability of MX to induce mutations was investigated in the liver of medaka (Oryzias latipes), a small fish model, utilizing the cII transgenic medaka strain that allows detection of in vivo mutations. Methylazoxymethanol-acetate (MAMAc), a carcinogen in medaka, served as a positive control. Fish were exposed to MX at 0, 1, 10 or 30 mg/L for 96 h whereas the MAMAc exposures were for 2 h at 0, 0.1, 1 or 10 mg/L. Both exposures were conducted under static water conditions and with fasted medaka. Following exposure, fish were returned to regular culture conditions to allow mutation expression for 15 or 40 d for MX or for 15 or 32 d for MAMAc. Mutations were not induced in medaka exposed to MX for 96 h. However, a concentration and time-dependent increase in mutations was observed from the livers of fish exposed to 1 and 10 mg/L MAMAc. In conclusion, mutation induction was not observed in the livers of cII medaka exposed to MX for 96 h, however studies are planned to examine mutation induction in the gills and skin to explore the possibility that MX-induced DNA damage occurs primarily in the tissues of initial contact.