title: A new medium-term bioassay system for detection of environmental carcinogens using diethylnitrosamine-initiated rat liver followed by D-galactosamine treatment and partial hepatectomy.
abstract: The effects of D-galactosamine on induction of preneoplastic glutathione S-transferase placental form positive liver foci were investigated in F344 rats pretreated with diethylnitrosamine (DEN) in an attempt to improve the predictive value of the medium-term bioassay system developed in our laboratory. Two weeks after the initial single ip dose (200 mg/kg) of DEN, administration of test compounds was commenced simultaneously with an ip injection of D-galactosamine at a dose of 300 mg/kg body wt. All rats were then subjected to two-thirds partial hepatectomy (PH) at week 5 and sacrificed for assessment of lesion yield at week 8. Measurement and comparison of the numbers and areas of glutathione S-transferase placental form positive (GST-P+) foci per cm2 revealed a positive response to more carcinogens, including non-hepatocarcinogens, than did the same bioassay system without injection of D-galactosamine. Thus the results suggest that inclusion of this extra proliferative stimulus may improve the medium-term detection of carcinogens and modifiers.
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods; D002273:Carcinogens / Q000032:analysis*; D004052:Diethylnitrosamine; D005688:Galactosamine / Q000494:pharmacology*; D005982:Glutathione Transferase / Q000378:metabolism; D006498:Hepatectomy; D008113:Liver Neoplasms / Q000139:chemically induced*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D004052:Diethylnitrosamine; D005688:Galactosamine; D005982:Glutathione Transferase