Analysis of carcinogenic activity of some pesticides in a medium-term liver bioassay in the rat.
Eight pesticides were tested in a medium-term bioassay based upon the induction of preneoplastic lesions in the liver. Rats were initially given diethylnitrosamine intraperitoneally at a dose of 200 mg/kg body weight and 2 weeks later were treated with the pesticides for 6 weeks and then killed; all rats had a partial hepatectomy at week 3. Hepatocarcinogenic potential was assessed by comparing the number and area of glutathione S-transferase placental form positive foci in the liver with those of controls given diethylnitrosamine (DEN) alone. Positive results were seen with p,p-DDT and Triadimefon. Permethrin (mixture of 39% cis form and 61% trans form) showed borderline results. Permethrin (25/75), Deltamethrin, Cypermethrin (52/48), while Trimorphamide and Propineb gave negative results. Our findings provide experimental evidence to indicate that compounds active in this assay have a potential for liver carcinogenicity in rodents.
First Department of Pathology, Nagoya City University Medical School, Japan.
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K
Hakoi
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R
Cabral
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T
Hoshiya
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R
Hasegawa
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T
Shirai
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Ito
D000818:Animals; D001681:Biological Assay; D002274:Carcinogens, Environmental / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D010575:Pesticides / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
D002274:Carcinogens, Environmental; D010575:Pesticides