The identification and assay of 2-methyl-5-nitroimidazole in pigs treated with dimetridazole.
An unidentified metabolite of dimetridazole (DMZ), found in pig plasma, muscle and kidney, was shown by chromatography and spectroscopy to be 2-methyl-5-nitroimidazole (2-MNI), resulting from N-demethylation of DMZ. This route of degradation competes with the oxidation pathway previously described. The concentration of 2-MNI in the plasma of pig fed medicated diet (DMZ 0.0125%) ranged from 29 to 83 ppb, 2 hours after the morning meal, similar to DMZ, but lower than that of the major metabolite, 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI). Its elimination profile in plasma was biphasic, similar to those of HMMNI and DMZ. Early and terminal half lives were 2.6 and 9.1 h respectively. None of the metabolites could be detected in any of the tissues studied 49 hours after withdrawal.
Carignan
G
G
Drug Residues Section, Bureau of Drug Research, Health and Welfare Canada, Ottawa, Ontario.
Carrier
K
K
Sved
S
S
D000818:Animals; D002138:Calibration; D004131:Dimetridazole / Q000378:metabolism*; D004350:Drug Residues / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D009593:Nitroimidazoles / Q000032:analysis*; D013552:Swine
D009593:Nitroimidazoles; C052586:2-methyl-5-nitroimidazole; D004131:Dimetridazole