title: Failure to induce tumors in the large intestine of Capuchin mokeys (Cebus apella) by using 1,2-dimethylhydrazine.
abstract: The purpose of this study was to produce tumors in the large intestine of Capuchin Monkeys (Cebus apella) by the administration of the colonotropic carcinogen 1,2-dimethylhydrazine (DMH). The subjects were 12 monkeys, all males, age 30 months, with a mean weight of 2.858 kg. The DMH was administered subcutaneously to six of the monkeys at a dosage of 25 mg/kg of body weight once a week for 16 weeks; control monkeys received an equivalent volume of the stock solution without DMH. Twenty months after administration of the first dose, the animals were sacrificed. None of the monkeys showed intestinal tumors. Samples of the gastrointestinal tract were removed, fixed, and stained according to standard histological techniques. Histological changes were seen in all of the DMH-treated animals; these consisted of glandular hyperplasia and hyperplasia of the epithelium overlying the lymphoid nodules. In addition, foci of dysplasia were found in three of the animals. Our results suggest that the DMH induced pre-neoplastic changes, characterized by hyperplasia and dysplasia, in the mucosa of the large intestine.
authors.affiliation: Facultad de Ciencias Veterinarias, Universidad Nacional del Nordeste, Corrientes, Argentina. patgral@vet.unne.edu.ar
authors.forename: M
authors.initials: M
authors.lastname: Sánchez Negrette
authors.forename: J T
authors.initials: JT
authors.lastname: Borda
authors.forename: M A
authors.initials: MA
authors.lastname: Montenegro
authors.forename: W J
authors.initials: WJ
authors.lastname: Lertora
authors.forename: E J
authors.initials: EJ
authors.lastname: Gimeno
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D002273:Carcinogens / Q000008:administration & dosage / Q000009:adverse effects*; D002428:Cebus; D006965:Hyperplasia; D007279:Injections, Subcutaneous; D007414:Intestinal Neoplasms / Q000139:chemically induced / Q000662:veterinary*; D007420:Intestine, Large / Q000473:pathology*; D008297:Male; D009374:Neoplasms, Experimental; D011230:Precancerous Conditions / Q000139:chemically induced / Q000662:veterinary
chemical_list: D002273:Carcinogens; D019813:1,2-Dimethylhydrazine