title: Effects of ergothioneine, cysteine, and glutathione on nitrosation of secondary amines under physiologic conditions.
abstract: The effects of ergothioneine, cysteine, and glutathione, which are naturally occurring sulfhydryl compounds, on the aerobic and anaerobic nitrosation of dimethylamine were studied at pH 2.0-7.0 and at 37 degrees C. Under aerobic conditions, ergothioneine increased the formation of dimethylnitrosamine (DMN) at all pH values tested, cysteine and glutathione had the same effect at pH 4.0-6.0, and cysteine formed DMN at pH 7.0. However, as compared to controls cysteine showed no increased effect in an O2 atmosphere at pH 6.0. The effects of sulfhydryl compounds on anaerobic nitrosation were more significant (p < 0.001) than on aerobic nitrosation, probably because these sulfhydryl compounds, except ergothioneine, are easily oxidized. Ergothioneine increased aerobic nitrosation almost as strongly as anaerobic nitrosation. The effects of sulfhydryl compounds, especially ergothioneine, on nitrosation at physiologic pH and temperature might be significant in the in vivo formation of N-nitrosamines in the hemorrhage or ulcerous gastrointestinal tract or injured organs.
mesh_terms: D000818:Animals; D003545:Cysteine / Q000494:pharmacology*; D004880:Ergothioneine / Q000494:pharmacology*; D005767:Gastrointestinal Diseases / Q000378:metabolism; D006471:Gastrointestinal Hemorrhage / Q000378:metabolism; D005978:Glutathione / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D009573:Nitrites / Q000378:metabolism; D009602:Nitrosamines / Q000096:biosynthesis*; D010100:Oxygen; D051381:Rats; D013696:Temperature
chemical_list: D009573:Nitrites; D009602:Nitrosamines; D004880:Ergothioneine; D005978:Glutathione; D003545:Cysteine; D010100:Oxygen