The induction of resistant hepatocytes during initiation of liver carcinogenesis with chemicals in rats fed a choline deficient methiomne low diet

Abstract

Feeding a choline deficient methiomne low (CLD) diet for two weeks can substitute for partial hepatectomy in the genesis with benzo[a]pyrene (B[a]P) or 1,2-dimethylhydrazine (1,2-DMH) of resistant hepatocytes that can be selected with dietary 2-acetylaminofluorene plus partial hepatectomy. With single doses of B[a]P or 1,2-DMH during the feeding of the CLD diet for 3 weeks, the number of foci of hepatocytes positive for γ-glutamyl transferase is approximately the same as with the same dose of each carcinogen given after partial hepatectomy. DL-ethionine was now found to be positive when given as a single dose to animals on the CLD diet. Feeding ethionine for 6 or 12 weeks in a similar choline lipotrope deficient diet also induced a significant increase in foci of enzyme altered hepatocytes. The results indicate that dietary imbalance can have an important influence on initiation of chemical carcinogenesis.