Carcinogenicity of N-nitroso derivatives of N-methylcarbamate insecticides in rats

Lijinsky, William; Schmähl, D

doi:10.1016/s0147-6513(78)80014-1

Cited by 30 publications

(11 citation statements)

References 10 publications

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“…Carbaryl has been observed to react with certain nitrogen-containing compounds, such as sodium nitrite, to form nitrosocarbaryl, which has been found to cause skin cancer when painted on mice (Deutsch-Wenzel et al 1985) , and cancer of the stomach in rats (Lijinsky and Schmahl 1978 ;Lijinsky and Taylor 1976) . Nitrosocarbaryl belongs to the N -nitrosoamines class of chemicals, of which some 70% to date have been found to be carcinogenic (Cox 1993) .…”

Section: Higher-order Organismsmentioning

confidence: 99%

Environmental Fate and Toxicology of Carbaryl

Gunasekara

Rubin

Goh

et al. 2008

Reviews of Environmental Contamination and Toxicology

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Section: Higher-order Organismsmentioning

confidence: 99%

Environmental Fate and Toxicology of Carbaryl

Gunasekara

Rubin

Goh

et al. 2008

Reviews of Environmental Contamination and Toxicology

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“…In addition to being potent bacterial mutagens [158], presumably bccause they are powerful methylating agents, they have also been shown to affect the structure of DNA [159]. Like nitrosomethylurethane (94), nitrosocthylurethane (95) and nitroso-N-methylphenylcarbamate (94a), these compounds are potent carcinogens in F344 rats when given by the oral route, but induce only one type of tumor, squamous cell carcinomas/pa- pillomas of the forestomach [160,161]. When painted on mouse skin, nitroso-N-alkylcarbamate esters, mostly esters of N-methylcarbamic acid, are either very weak carcinogens [93] like nitrosocarbaryl (94b), or are not carcinogenic [61].…”

Section: Ftg12mentioning

confidence: 99%

Structure-activity relations in carcinogenesis by N-nitroso compounds

Lijinsky

1987

Cancer Metast Rev

110

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For a large number of N-nitroso compounds a comparison of their carcinogenic effects in rats and Syrian golden hamsters has been made. Nitrosamines, which require metabolic activation, and nitrosoalkylamides, which do not, produce quite different tumor responses. There are also large differences in the types of tumor induced in rats and in hamsters. In all the studies doses of the various compounds, equimolar to the extent that was possible, are administered orally. Continuous doses (in drinking water or food) often produce a response different from that after administration of the same compound in pulsed doses (by gavage), even though the same total dose is delivered. Continuous doses of nitrosamines are usually more effective than pulsed doses, but with the nitrosoalkylureas, the reverse is more generally the case. Rat and hamster liver is a common target of many nitrosamines, but rarely of nitrosamides. The most common site of tumor induction in rats by N-nitroso compounds is the esophagus, but the hamster esophagus never responds. The pancreas duct of the hamster is a common target of nitrosamines containing a beta-oxygenated propyl group, but pancreas duct tumors are never seen in rats. Nitrosomethyl-n-alkylamines (with an even numbered carbon chain) induce bladder tumors in rats and hamsters. Many nitrosoalkylureas induce tumors of the nervous system in rats, as well as a great variety of other tumors. In hamsters, nitrosoalkylureas give rise only to tumors of the forestomach and spleen, but no tumors of the nervous system. The similar carcinogenic actions of certain groups of N-nitroso compounds can be related to their generation, directly or by metabolism, of similar simple moieties having certain organs as their target.

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“…mild acid and 37°C) in the presence of nitrites or nitrogen oxides (12,(14)(15)(16). NP is not a cholinesterase inhibitor and is less toxic to mammals than propoxur.…”

Section: Introductionmentioning

confidence: 99%

Genotoxicity of propoxur and its N-nitroso derivative in mammalian cells

Wang

Chiou²,

Hu³

1998

Carcinogenesis

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N-Nitroso propoxur (NP) can be synthesized from a widely used N-methylcarbamate insecticide, propoxur, in vitro in the laboratory. Because of the extensive use of aerosol propoxur, the adverse effect on cells of respiratory origin is worth elucidating. In this report, two mammalian cell cultures from respiratory tissues [a hamster lung fibroblast, V79, and a primary rat tracheal epithelial cell (RTE)], were used to investigate the genotoxicity of propoxur and NP. NP was more cytotoxic than propoxur, with LC 50 s (20 and six times smaller, respectively in V79 and RTE cells. NP significantly induced sister chromatid exchange (ജ0.01 µg/ml), chromosome aberration (ജ2.5 µg/ml) and hprt gene mutation (ജ0.5 µg/ml) in V79 cells, and cell transformation (ജ0.2 µg/ml) in RTE cells. Results of chromosome aberration and hprt gene mutation indicated that the major pre-mutagenic lesion induced by NP must be the O 6 -methylguanine adduct, which frequently mispairs with thymine and thus gives rise to a GC→AT transition. Propoxur was not mutagenic to either type of cells. However, it inhibited gap-junctional intercellular communication in V79 cells, which indicates that propoxur could act through some epigenetic mechanisms, such as tumor promotion or cell proliferation, in the multiple process of chemical carcinogenesis.

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Carcinogenicity of N-nitroso derivatives of N-methylcarbamate insecticides in rats

Cited by 30 publications

References 10 publications

Environmental Fate and Toxicology of Carbaryl

Environmental Fate and Toxicology of Carbaryl

Structure-activity relations in carcinogenesis by N-nitroso compounds

Genotoxicity of propoxur and its N-nitroso derivative in mammalian cells

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