title: Mesotheliomas and proliferative lesions of the testicular mesothelium produced in Fischer, Sprague-Dawley and Buffalo rats by methyl(acetoxymethyl)nitrosamine (DMN-OAc).
abstract: A single intraperitoneal dose of methyl(acetoxymethyl)nitrosamine (13 mg/kg body weight) given to 78 5-week-old male rats induced 25 mesotheliomas; two mesotheliomas were found in 67 control rats. All mesotheliomas arose from the peritesticular mesothelium and had a typical microscopic appearance of branching papillary fronds with a collagenous core covered by one or many layers of plump tumor cells. Cytoplasm of tumor cells contained material that reacted positively to a colloidal iron stain and was labile to hyaluronidase. In addition to frank mesotheliomas, 16 lesions, which we called atypical mesothelial proliferations, were found. These consisted of a single focus of plump mesothelial cells overlying an area of thick stroma. Often these foci included short, non-branched papillary projections above the surface of adjacent normal mesothelium. Twelve of the 16 lesions occurred in methyl(acetoxymethyl)nitrosamine-treated rats.
mesh_terms: D000818:Animals; D004128:Dimethylnitrosamine / Q000031:analogs & derivatives; D004195:Disease Models, Animal; D008297:Male; D008654:Mesothelioma / Q000139:chemically induced* / Q000473:pathology; D009602:Nitrosamines / Q000031:analogs & derivatives; D051381:Rats; D013736:Testicular Neoplasms / Q000139:chemically induced* / Q000473:pathology
chemical_list: D009602:Nitrosamines; D004128:Dimethylnitrosamine