Analysis of the Effects of Modifying Agents on Six Different Phenotypes in Preneoplastic Foci in the Liver in Medium-Term Bioassay Model in Rats

Recently a great deal of interest has been expressed in characterizing the altered enzyme phenotype of putative preneoplastic rat liver lesions. In particular, attention has been given to the changes in drug metabolizing potential, conferring physiological advantage to initiated cells, and their usefulness as marker lesions for the analysis of the development of neoplasia1–2.