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This study was performed for developing a new medium-term carcinogenicity bioaasay using D-galctosamine(DGA) as a non-surgical method without partial hepatectomy(experiment I), and validating its ability to detect carcinogens(experiment II). Enhancing effect of DGA, given twice during the promotion procedure by 2-acetylaminofluorene, was compared along with partical hepateetomy(PH) in F344 male rats initiated by diethylnitrosamine, using preneoplastic glutathione S-transferase placental from positive(GST-P+) hepatocyte foci as an end-point marker lesions. Assays of the hepatocarcinogenic potential of several different chemicals(phenobarbital, 3-methylcholanthrene, n-ethyl-n´-nitro-n-nitrosoguanidine, 3,3´-diaminobenzidine) were also carried out using the medium-term bioassay without PH. The number and area of GST-P + foci per cm2 were Larger in the bioassay using DGA than that using PH. Phenobarbital and 3-methylcholanthrene gave positive results. Therefore the results suggest that the medium-term carcinogenicity bioassay using DGA is as sensitive as that using PH in detecting not only hepatocarcinogens but non-hepatocarcinogens.
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