Tumors of the liver, kidneys, and lungs have been induced in rats by the feeding of dimethyl nitrosamine (DMN) and diethylnitrosamine (DENA) (1, 11, 12, 18). Dontenwill et al. (3, 4) reported that squamous-cell carcinoma of the trachea and lung of Syrian hamsters followed ad ministration of DENA by each of three ap proaches—tube feeding, inhalation, and subcu taneous injection. They observed ...

A rabbit cytochrome P-450llE2 full-length cDNA was cloned into a yeast episomal plasmid (YEp13) between the copper-responsive yeast metallothionein gene promoter (CUP7) and the iso-I-cytochrome c gene terminator (CYCI), and the cytochrome P-450 was expressed in Saccharomyces cerevisiae. The microsomal fraction prepared from copper-treated cells exhibited a ferrous carbonyl difference spectrum w...

A sensitive and selective method was developed and validated to detect six volatile nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopiperidine, N-nitrosopyrrolidine and N-nitrosomorpholine) in human urine. This method uses a liquid-liquid extraction cartridge followed by analysis with gas chromatography-tandem mass spectrometry (GC-MS-MS) and qua...

N-nitroso compounds (NOCs) may be implicated in human colon carcinogenesis, but the toxicological mechanisms involved have not been elucidated. Because it was previously demonstrated that nitrosamines and nitrosamides, representing two classes of NOC, induce distinct gene expression effects in colon cells that are particularly related to oxidative stress, we hypothesized that different radical ...

Male F344/NCr rats, 6 wk old, were fed 500 ppm of phénobarbital (PB) or equimolar doses of either 5-ethyl-5-phenylhydantoin (EPH) or 5,5-diethylhydantoin (EEH) in diet for 2 wk and hepatic cytochrome P450-mediated alkoxyresorufm 0-dealkylase and aminopyrine A'-demethylase activities were determined. Both PB and EPH greatly increased P450-mediated enzyme activities in rat liver while EEH was in...

A method has been developed for the determination of eight N-nitrosamines in drinking water and treated municipal effluent. The method uses solid phase extraction (SPE), gas chromatography (GC) and analysis by tandem mass spectrometry (MS-MS) with electron ionization (EI). The target compounds are N-nitrosodimethylamine (NDMA), N-nitrosomethyethylamine (NMEA), N-nitrosodiethylamine NDEA), N-nit...

      This study was designed to explore the protective effects of Abrus precatorius L. (Leguminosae) (AP) in HepG2 cells and N-nitrosodiethylamine (NDEA) induced hepatocellular carcinoma in Swiss albino rats. The effects of aqueous/ethanolic (50%) extract of AP on hepatic markers, haematological and histopathological parameters, and antioxidant enzymes were evaluated in NDEA ...