title: Morphological and biological characteristics of mammary tumours induced by the direct application of DMBA powder to rat mammary glands.
abstract: Mammary tumours were induced by the direct dusting of 1 mg, 7,12-dimethylbenz(a)anthracene (DMBA) powder onto the mammary gland of both 30-day-old female and male Sprague-Dawley rats, and the tumours were examined histologically. Mammary tumours developed in 43/43 (100%) of the females 11 to 20 weeks after DMBA dusting and 16/23 (70%) of the males 18 to 28 weeks after dusting, while non-mammary spindle cell sarcomas occurred in 5/23 (22%) of the males 15 to 24 weeks after dusting. A variety of benign and malignant mammary tumours of epithelial and/or mesenchymal origin were induced, which are comparable to human mammary tumours. Different histological patterns were observed in different areas of the same tumours. Ovariectomy revealed hormone (ovary)-dependency in 10/17 (59%) of the tumours, revealing regressing epithelial and proliferating mesenchymal tumour elements on histological examination.
authors.affiliation: Department of Pathology, Kansai Medical University, Osaka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tsubura
authors.forename: N
authors.initials: N
authors.lastname: Shikata
authors.forename: T
authors.initials: T
authors.lastname: Inui
authors.forename: N
authors.initials: N
authors.lastname: Sakaida
authors.forename: S
authors.initials: S
authors.lastname: Morii
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity*; D000230:Adenocarcinoma / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure; D000231:Adenocarcinoma, Papillary / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure; D000818:Animals; D003528:Carcinoma, Adenoid Cystic / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure; D002296:Carcinosarcoma / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000139:chemically induced / Q000473:pathology / Q000648:ultrastructure
chemical_list: D015127:9,10-Dimethyl-1,2-benzanthracene