title: Lack of evidence of carcinogenicity of technical-grade piperonyl butoxide in F344 rats: selective induction of ileocaecal ulcers.
abstract: The carcinogenicity of technical-grade piperonyl butoxide was studied in F344/DuCrj rats fed a dietary level of 0.5 or 1% for 2 yr. Various tumours were detected in all groups, including the untreated control group, but no significant dose-related increase in the incidence of any tumour was found. Thus, it is concluded that under these experimental conditions piperonyl butoxide was not carcinogenic in F344 rats. Unexpectedly, however, ileocaecal ulcers were found in animals of both sexes in both experimental groups and the incidence was dose related. Further studies are required to establish the mechanism of induction of ileocaecal ulcers by piperonyl butoxide.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002273:Carcinogens; D005260:Female; D007077:Ileal Diseases / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced; D010882:Piperonyl Butoxide / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D014456:Ulcer / Q000139:chemically induced* / Q000473:pathology
chemical_list: D002273:Carcinogens; D010882:Piperonyl Butoxide