title: Induction of peroxisome proliferation and hepatic tumours in C57BL/6N mice by ciprofibrate, a hypolipidaemic compound.
abstract: The hepatic effects of ciprofibrate, a potent peroxisome proliferator, were evaluated in male C57BL/6N mice, a mouse strain with very low incidence of spontaneous liver tumour development. Dietary feeding of ciprofibrate (0.0125% or 0.025% w/w) for 2 weeks resulted in a marked proliferation of peroxisomes (9-fold increase) and several-fold increase (8- to 10-fold) in the activity of peroxisomal beta-oxidation enzymes. Feeding ciprofibrate at 0.025% concentration for 15 months followed by a 0.0125% for 6 months led to the development of hepatic adenomas in 8/14 (57%) and hepatocellular carcinomas (HCC) in 3/14 (21%) mice. In mice given 0.0125% ciprofibrate for 18 months 5 of 8 (62%) and 3 of 8 (37%) developed adenomas and HCC respectively. Similar to the findings observed in rats, both the adenomas and HCC were negative for gamma-glutamyltranspeptidase. These results in C57BL/6N mice of hepatocarcinogenic effect of ciprofibrate, a non-genotoxic chemical, indicate that peroxisome proliferation can be used as a reliable parameter to evaluate the carcinogenicity of hypolipidaemic compounds.
mesh_terms: D000236:Adenoma / Q000139:chemically induced; D000818:Animals; D002994:Clofibrate / Q000031:analogs & derivatives*; D002995:Clofibric Acid / Q000031:analogs & derivatives* / Q000633:toxicity; D058607:Fibric Acids; D000960:Hypolipidemic Agents / Q000633:toxicity*; D008099:Liver / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000201:enzymology / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008830:Microbodies / Q000187:drug effects; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D058607:Fibric Acids; D000960:Hypolipidemic Agents; D002995:Clofibric Acid; D005723:gamma-Glutamyltransferase; C019304:ciprofibrate; D002994:Clofibrate