chemistry Nitrosamines (NAs) are a family of chemical compounds discovered over 100 years ago. It was not until the 1950s that these compounds received worldwide attention. In the 1950s, two British scientists, Barnes and Magee discovered that dimethylnitrosamine is a powerful carcinogen in laboratory animals. This finding led to massive studies involving NAs in many industries throughout the y...

Quantitative autoradiograms were made, in vivo, in European hamsters with the use of [14C]nitrosoheptamethyleneimine (260 muCi/animal; time between administration of nitrosamine and killing of animals, 6 hr). In this species, the lung is the principal target, and radioactivity was found in the Clara cells of the bronchial epithelium and in the nitrosoheptamethyleneimine-induced tumors which der...

Pancreatitis, a debilitating inflammatory disorder, results from pancreatic injury. Alcohol abuse is the foremost cause, although cigarette smoking has recently surfaced as a distinct risk factor. The mechanisms by which cigarette smoke and its toxins initiate pathological cellular events leading to pancreatitis, have not been clearly defined. Although cigarette smoke is composed of more than 4...

Contamination of nitrosamine compounds in Chinese sausages and the relevant hepatoxicity have been reported. This study was conducted to evaluate effects vitamin C (VC) supplementation on sausage contaminated with N-nitrosodimethylamine (NDMA)-induced liver damage metabolomic changes. Rats were orally administered NDMA at levels overpassing its safety limit. In some experiments, VC additionally...

Objective(s):Green tea (GT) is one of the most popular beverages worldwide whose beneficial effects on health have been demonstrated. Recent studies suggest that GT may contribute to reduction of cancer risk and progression. The aim of this study was to evaluate the effects of whole GT on urinary bladder chemical carcinogenesis in male and female ICR mice. Materials and Methods: The GT charact...

The role of transforming growth factor-β (TGF-β) signaling in cancer progression is still under debate. To determine the function of TGF-β signaling in bladder cancer progression, we conditionally knocked out the Tgfbr2 in mouse model after a N-butyl-N-4-hydroxybutyl Nitrosamine induced bladder carcinogenesis. We found the ablation of TGF-β signaling could inhibit the cancer cell proliferation,...

Ovarian and testicular tumors were induced in the offspring (F1 generation) of MRC rats that received single or multiple doses of N-nitrosobis(2-oxopropyl)amine on the 14th, 18th, and/or 20th days of pregnancy. The ovarian tumor incidence was significantly higher (46%) in the F1 generation exposed to the carcinogen a single time at the 18th day of gestation, when compared to those exposed at th...

This paper describes quantitation of human hemoglobin and DNA adducts of the carcinogenic tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN). NNK and NNN are believed to be involved in cancers of the lung, esophagus, oral cavity, and pancreas in people who use tobacco products. The adduct dosimetry method employs GC-MS for quantita...