Uptake by rat stomach tissues of 2-aminofluorene-3H hydrochloride and 2,7-diaminofluorene-3H hydrochloride in vitro.

ALTHOUGH adenocarcinoma of the stomach is one of the commonest and most malignant forms of cancer in man, it has proved very difficult to reproduce in animals (Stewart, Snell and Hare, 1958). A few adenocarcinomas were obtained by the implantation of crystals of aromatic hydrocarbons in the mucosa of the stomach of mice. We felt, however, that if a carcinogenic compound could be found that was secreted by the stomach, it would come into intimate contact with immature glandular cells and so cause gastric adenocarcinoma (Ray and Jung, 1951). This proved to be the case and for the first time unmistakable adenocarcinomas were produced in the stomach of the rat by feeding the dibasic carcinogen, 2,7-diacetylaminofluorene * (2,7-DAAF) (Morris, Wagner, Ray, Snell and Stewart, 1961). The closely related compound 2-acetylaminofluorenet (2-AAF), while causiIng many other tumors, has failed to produce cancer of the glandular stomach. It has since been shown quantitatively by Ray, Cromer, Aycock and Pitzer (1961) that the former compound (2,7-DAAF) was deposited in vivo in the stomac

Induction of Carcinomas in the Nasal Cavity of Rats by Dioxane

Six out of 120 rats fed dioxane in drinking water at levels of 0.75, 1.0, 1.4 or 1.8% developed carcinomas in the nasal cavity. Spontaneous tumors at this tissue localization have not been reported to occur in laboratory animals. The carcinomas were pre-eminently of epidermoid type with few adenocarcinomatous areas and epithelial papillomas. Four rats with carcinoma of the nasal cavity had hepatocellular carcinoma in addition

Enzyme studies of the liver of rats during carcinogenesis by diethylnitrosamine.

STUDIES on the,J-glucuronidase and lactic dehydrogenase (LDH) activities in rat organs during tumor production by feeding dimethyl-(DMN) or diethylnitrosamine (DEN) have been reported previously (Hoch-Ligeti, Lobl and Arvin, 1964). In continuation of these experiments changes in concentration and intracellular localization of these and some other enzyme systems have been investigated. The enzymes were chosen with regard to their different intracellular localization. Although there is still considerable controversy about the intracellular localization of some enzymes, the localization of others is so well established that their presence in a subcellular fraction permits the conclusion that certain morphological entities are also present. Succinoxidase is localized i