title: Comparison of chloroform-induced toxicity in the kidneys, liver, and nasal passages of male Osborne-Mendel and F-344 rats.
abstract: Chloroform given by gavage in corn oil at 180 mg/kg per day induced kidney tumors in male Osborne-Mendel rats. Chloroform-induced cytotoxicity and regenerative cell proliferation have been observed in the kidneys of male F-344 rats. In order to compare the acute sensitivity of male Osborne-Mendel with F-344 rats, animals from both strains were administered a single gavage dose of 0, 10, 34, 90, 180, or 477 mg/kg chloroform and necropsied 48 h later. Known target tissues were examined for histological changes. Regenerative cell proliferation was assessed as a labeling index (LI, percent of cells in S-phase) as determined by nuclear incorporation of bromodeoxyuridine. The epithelial cells of the proximal tubules of the kidney cortex were the primary target cells for cytotoxicity and regenerative cell proliferation. A dose-dependent increase in the LI was present in the kidney of Osborne-Mendel rats given doses of 10 mg/kg chloroform and above and in F-344 rats given 90 mg/kg and above. The maximal increase in the LI was 4.5- or 3.7-fold over control in Osborne-Mendel or F-344 given 477 mg/kg, respectively. The only increase in the hepatocyte LI was in the F-344 rats given 477 mg/kg. Edema and periosteal hypercellularity were observed in the nasal passages of both strains at doses of 90 mg/kg and above. These data indicate that Osborne-Mendel and F-344 rats are about equally susceptible to chloroform-induced nephrotoxicity. These results provide a basis for linking the extensive data base on mechanisms of action of chloroform toxicity in F-344 rats to the Osborne-Mendel rat and support the hypothesis that events secondary to chloroform-induced cytolethality and regenerative cell proliferation played a role in the induction of renal tumors in the Osborne-Mendel rat.
authors.affiliation: Chemical Industry Institute of Toxicology, Research Triangle Park, NC 27709-2137, USA.
authors.forename: M V
authors.initials: MV
authors.lastname: Templin
authors.forename: K C
authors.initials: KC
authors.lastname: Jamison
authors.forename: D C
authors.initials: DC
authors.lastname: Wolf
authors.forename: K T
authors.initials: KT
authors.lastname: Morgan
authors.forename: B E
authors.initials: BE
authors.lastname: Butterworth
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D056486:Chemical and Drug Induced Liver Injury; D002725:Chloroform / Q000633:toxicity*; D007668:Kidney / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D007674:Kidney Diseases / Q000139:chemically induced* / Q000473:pathology; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D008107:Liver Diseases / Q000473:pathology; D008115:Liver Regeneration / Q000187:drug effects; D008297:Male; D010256:Paranasal Sinuses / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011916:Rats, Inbred F344; D012038:Regeneration / Q000187:drug effects; D012680:Sensitivity and Specificity
chemical_list: D002725:Chloroform