Differentiation of the mechanisms of oncogenicity of 1,4-dioxane and 1,3-hexachlorobutadiene in the rat

Stott, WT; Quast, JF; Watanabe, PG

HERO ID

1937837

Reference Type

Journal Article

Year

1981

Language

English

PMID

7281189

HERO ID 1937837
In Press No
Year 1981
Title Differentiation of the mechanisms of oncogenicity of 1,4-dioxane and 1,3-hexachlorobutadiene in the rat
Authors Stott, WT; Quast, JF; Watanabe, PG
Journal Toxicology and Applied Pharmacology
Volume 60
Issue 2
Page Numbers 287-300
Abstract HEEP COPYRIGHT: BIOL ABS. 1,4-Dioxane (DX) and 1,3-hexachlorobutadiene (HCBD) have induced liver and kidney neoplasms, respectively, upon chronic ingestion of cytotoxic dosages to rats. DX and HCBD were compared in male Sprague-Dawley rats to the genotoxic carcinogen dimethylnitrosamine (DMN) with regard to cytotoxicity (DNA synthesis, histopathology) and genotoxicity (DNA alkylation, in vivo DNA repair). Treatment of rats with tumorigenic dose levels of DX (1 g/kg per day) in drinking water for 11 wk or HCBD (20 mg/kg per d, po) for 3 wk resulted in a 1.5 increase in hepatic DNA synthesis and a 1.8 increase in renal DNA synthesis, respectively. Treatment-related histopathological changes were also observed in treated animals. Cytotoxicity was not detected in rats dosed orally with nontumorigenic levels of DX (10 mg/kg per day), HCBD (0.2 mg/kg per day) or with a tumorigenic dose level of DMN (3 mg/kg per d) for 3 wk. Alkylation of hepatic DNA and DNA repair were not detected in rats dosed with 1 g (14C)DX/kg (po). Renal DNA alkylation (0.78 alkylation/106 nucleotides) and a 1.40 increase in DNA repair were observed in rats dosed with 20 mg (14C)HCBD/kg (po). Neither compound elicited a positive response in the Ames' bacterial mutagenicity or Williams' hepatocyte DNA repair in vitro assay. Rats dosed with 3 mg (14C)DMN/kg po resulted in alkylation of hepatic and renal DNA at levels of 167 and 28.3 alkylations/106 nucleotides, respectively. Large increases in hepatic (3.72 ) and renal (2.87 ) DNA repair were also noted in DMN-dosed rats (20 mg/kg, po). The lack of genotoxic activity by DX and its cytotoxicity at tumorigenic dose levels suggests a nongenetic mechanism of liver tumor induction in rats. Unlike DX, the data suggested that HCBD has a relatively low degree of generic interaction. While kidney tumors, induced only at toxic HCBD doses, may be caused primarily by a nongenetic mechanism, a minor generic contribution cannot be discounted.
Doi 10.1016/0041-008X(91)90232-4
Pmid 7281189
Wosid WOS:A1981MF83800014
Url https://linkinghub.elsevier.com/retrieve/pii/0041008X91902324
Is Certified Translation No
Dupe Override No
Comments Journal: TOXICOL APPL PHARMACOL 60 ISSN:
Is Public Yes
Language Text English
Keyword Alkylation; Animals; Body Weight/drug effects; Butadienes/toxicity; Carcinogens; DNA/biosynthesis/metabolism; DNA Repair/drug effects; Dimethylnitrosamine/toxicity; Dioxanes/toxicity; Dioxins/toxicity; Organ Size/drug effects; Rats, Inbred Strains; 9007-49-2; CQ8AAO9MO1; J8A3S10O7S; M43H21IO8R
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