title: Methylation of rat and mouse DNA by the mushroom poison gyromitrin and its metabolite monomethylhydrazine.
abstract: Consumption of false morel (Gyromitra esculenta Fr.) has been associated not only with acute poisoning, but also with a carcinogenic risk. The hydrolysis of acetaldehyde-N-methyl-N-formylhydrazone (gyromitrin, the main toxic component of false morel) results in the formation of the methylating agents N-methyl-N-formylhydrazine (MFH) and N-methylhydrazine (MMH) (by further hydrolysis of MFH). This study reports traces of N-7-methylguanine (N7MeGu) in liver DNA from mice and a rat treated with gyromitrin. After repeated administration of MMH, N7MeGu was identified in rat liver DNA. In mice exposed to MMH according to a dosing scheme identical to that reported to induce tumours in this species, O6-methylguanine was present in liver and kidney DNA. The results indicate that a relatively low carcinogenic risk is associated with false morel consumption. The risk may be greater in individuals with a decreased detoxification rate (acetylation) of MFH, in whom larger amounts of MMH are formed from gyromitrin.
authors.affiliation: Toxicology Division, National Food Administration, Uppsala, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Bergman
authors.forename: K E
authors.initials: KE
authors.lastname: Hellenäs
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000378:metabolism; D000477:Alkylating Agents; D000818:Animals; D002273:Carcinogens; D004249:DNA Damage; D008099:Liver / Q000378:metabolism; D008745:Methylation; D051379:Mice; D009002:Monomethylhydrazine / Q000378:metabolism*; D051381:Rats
chemical_list: D000477:Alkylating Agents; D002273:Carcinogens; D000079:Acetaldehyde; C005666:gyromitrin; D009002:Monomethylhydrazine