| Abstract: | Posttreatment with diethyldithiocarbamate (DEDTC) largely prevented the development of acute hepatocellular necrosis induced by diethylnitrosamine (DEN) and dimethylnitrosamine (DMN) in male Fischer rats as monitored by the release of glutamate-pyruvate transaminase and sorbitol dehydrogenase into the serum and by histologic examination. Liver cell necrosis was evident with a dose of 25 mg of DEN/kg and was progressive with increasing doses of DEN. DEDTC (50 mg/kg; three times at 4-hour intervals) was given at 4 or 8 hours after the administration of DEN (100 mg/kg), time points at which at least 50% and 75%, respectively, of the administered DEN had disappeared from both the serum and liver. Under these conditions, DEDTC prevented liver cell necrosis, except for a few isolated cells. Similar inhibition was also observed when DEDTC was given 4 hours after the administration of a necrogenic dose of DMN (20 mg/kg). DEDTC, when administered 4 hours after DEN, delayed the rate of clearance of DEN and of ethylation of DNA and RNA but did not significantly affect the total extent of ethylation of rat liver nucleic acids. These results offer further support for the multistep hypothesis for the development of liver cell necrosis. |
