Carcinogenic responses to chemicals applied directly to rat mammary glands in situ
In four experiments, concentrated glycerin suspensions of 7,12-dimethylbenz(a)anthracene (DMBA), or the water-soluble compounds, N-methyl-N-nitrosourea (MNU), N-ethyl-N-nitrosourea (ENU), and 4-nitroquinoline-N-oxide (4-NQO) were delivered into pockets in the mammary fat pads in female Sprague-Dawley rats. In a 90-day experiment, each of three groups of 20-22 rats were treated with either 25, 50, or 100 ..mu..g DMBA delivered to each of four sites in each rat per group. Dose-related responses were detected for incidence of rats with mammary adenocarcinoma (MAC), and for number of MAC per treated site. In a 120-day study, each of three groups of 20 animals were treated with either 250, 500, or 1000 ..mu..g MNU at each of 80 sites per group. Dose-related MAC responses were detected for incidence of rats with MAC, number of MAC per treated site, and time to detection of MAC. In two experiments of 90 days duration, groups of 20 females were treated with either 1000 ..mu..g ENU or 1000 ..mu..g 4-NQO at each of 80 sites per group. ENU produced a total of 27 MAC sites in 65% of the rats, and 4-NQO produced a total of 26 MAC in 60% of the rats. A comparison of the time to detection of all MAC data for the three water-soluble compounds at the 1000 ..mu..g treatment level, or on the basis of moles per treatment, yielded a carcinogenic potency relationship of 4-NQO > ENU > MNU. 21 references, 2 figures, 1 table.
- Research Organization:
- Brookhaven National Lab., Upton
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 5718512
- Journal Information:
- Carcinogenesis; (United States), Vol. 6:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BENZANTHRACENE
CARCINOGENESIS
MAMMARY GLANDS
CARCINOMAS
NITRO COMPOUNDS
NITROSOUREAS
DOSE-RESPONSE RELATIONSHIPS
EXPERIMENTAL DATA
RATS
TOXICITY
ANIMALS
AROMATICS
BODY
CONDENSED AROMATICS
DATA
DISEASES
GLANDS
HYDROCARBONS
INFORMATION
MAMMALS
NEOPLASMS
NITROSO COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATHOGENESIS
RODENTS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)