ABSTRACT
This chapter investigates the utility of the observed decrease in hepatic pyruvate kinase (PK) assay as a potential screening test for hepatocarcinogenesis promoters. All test chemicals were added in a commercially available basal powder diet. Most of the hepatocarcinogens and potent hepatic promoters have been shown to decrease the liver PK activity. In order to compare the promoting activity of a variety of promoters, a relative promoting activity index was calculated for each tested chemicals using our experimental data or published data from the literature on promotion of hepatic cancer. The most important advantage of the PK method for screening potential hepatic promoters may be its simplicity and low cost. PK assays can be carried out using ordinary laboratory equipments and inexpensive chemical reagents. In contrast to promoters, complete hepatocarcinogens cause both a decrease in L-type and an increase in fetal-type PK isozymes.
