Effect of various chemicals on macromolecular binding during oxidative dealkylation of dimethylnitrosamine by hamster liver microsomes.

Differential inhibitory effects of various chemicals on both formaldehyde formation and total macromolecular binding have been examined during oxidative demethylation of [14C]dimethylnitrosamine (DMN) by hamster liver microsomes. One group of chemicals such as diethyldithiocarbamate (DEDTC), aminoacetonitrile (AAN), 2-[(2,4-dichloro-6-phenyl) phenoxy]-ethylamine (DPEA), azide and ethanol inhibits both HCHO formation and total macromolecular binding. A second group of chemicals such as reduced glutathione, semicarbazide and N-(1-naphthyl)thiourea (NTU) inhibits macromolecular binding without appreciably affecting HCHO formation. Possible mechanisms of these differential inhibitory effects by these chemicals are discussed.