Liver injury and alterations of hepatic microsomal monooxygenase system due to dimethylformamide (DMF) in rats.

The effects of repeated exposure to N, N-dimethylformamide (DMF) on the liver and the hepatic microsomal monooxygenase system were investigated. DMF was administered to Wistar male rats by subcutaneous (s.c.) injection at 0.5 ml/kg body weight daily for 1-17 days. Macroscopically, mild liver swelling was observed and liver weights significantly increased after 3 days of exposure to DMF respectively. Hematological changes were not observed. In exposed rats, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase significantly increased after 3 and 7 days of exposure to DMF. After 17 days of exposure to DMF, transaminases decreased compared to the 7 days. Hepatic microsomal cytochrome P-450 tended to decrease after 3 days of exposure DMF and decreased by 34% after 7 days and 25% after 17 days. Aminopyrine N-demethylase activity depressed significantly while aniline hydroxylase activity showed no change after 3 days of exposure to DMF. These results indicate that DMF alters the hepatic microsomal monooxygenase system. These findings may greatly contribute to the elucidation of the pathogenesis of DMF hepatotoxicity.