title: Neoplastic response to dmba powder in mammary and interscapular tissues in wistar furth and copenhagen female rats.
abstract: To investigate genetic factors in local tumorigenesis, a dusting of 1 mg of 7,12-dimethylbenz(a)-anthracene (DMBA) powder was directly applied to exposed mammary tissue in 15 Wistar/Furth (WF), 20 Copenhagen (Cop), 19 (WF x Cop) F1, 16 backcross (BC) (F1 x WF) and 19 BC (F1 x Cop) females, at the age of 30 days. By 28 weeks after dusting, gross tumors were induced in 15 WF, 17 Cop, 12 (WF x Cop) F1, 11 BC (F1 x WF) and 14 BC (F1 x Cop) rats. Depending on their neoplastic response, carcinomatous response was 93% in WF, 5% in Cop, 16% in (WF x Cop) F1, 31% in BC (F1 x WF) and 0% in BC (Fl x Cop) rats, and sarcomatous response was 20% in WF, 85% in Cop, 58% in (WF x Cop) F1, 44% in BC (F1 x WF) and 73% in BC (F1 x Cop) rats. When dusting was performed on the interscapular fat tissue of 21 WF and 22 Cop females at 38 days of age, sarcomas were found in 67% of WF and 91% of Cop rats. Therefore, susceptibility and supressor gene(s) are suspected in mammary epithelial cells of the WF and Cop, respectively, for carcinogenesis, while co-dominant allele for sarcomagenesis exists in the Cop and WF mammary stromal cells.
authors.affiliation: KANSAI MED UNIV,DEPT PATHOL,MORIGUCHI,OSAKA 570,JAPAN.
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Shoji
authors.forename: A
authors.initials: A
authors.lastname: Tsubura
authors.forename: S
authors.initials: S
authors.lastname: Morii