This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shellabarger, C. J. Articles by Holtzman, S. Search for Related Content PubMed PubMed Citation Articles by Shellabarger, C. J. Articles by Holtzman, S.

Interaction of Dimethylbenzanthracene and Diethylstilbestrol on Mammary Adenocarcinoma Formation in Female ACI Rats¹

Medical Department, Brookhaven National Laboratory, [C. J. S., J. P. S., S. H.], Upton, New York 11973 and Biostatistics, Wisconsin Clinical Center, University o Wisconsin, Madison, Wisconsin 53715 [B. M.]

It has been reported that X-irradiation and diethylstilbestrol (DES) act synergistically on mammary adenocarcinoma formation in female ACI rats. The physical carcinogen, X-irradiation, was replaced by a chemical carcinogen, dimethylbenzanthracene (DMBA), and their interaction was studied in this system. Thirty-three female ACI rats were given 13.3 mg of DMBA per 100 grams of body weight. A total of 10 mammary adenocarcinomas were found, 8 in rats with a single mammary adenocarcinoma and 2 in a single rat, over a 266-day study period. Twenty-nine rats were implanted with a cholesterol pellet containing 5 mg of DES, and a total of 47 mammary adenocarcinomas were found, 5 in rats with a single mammary adenocarcinoma and 42 in 5 rats with 2 or more mammary adenocarcinomas. Twenty-four rats were given a combined treatment of both compounds, DES 2 days before DMBA, and a total of 126 mammary adenocarcinomas were found, 2 in rats with a single mammary adenocarcinoma and 124 in 18 rats with 2 or more mammary adenocarcinomas. The interaction between DMBA and DES was interpreted to be synergistic in regard to the proportion of rats with one or more mammary adenocarcinomas, the proportion of rats with two or more mammary adenocarcinomas, and the median times of appearance of both first and second mammary adenocarcinomas. These interactions between DMBA and DES resemble the previously reported synergistic interactions between radiation and DES on mammary adenocarcinoma formation in female ACI rats.

¹ Research done under Contract Y01-CP-3021 with the Biological Models Segment of the Carcinogenesis Program of the National Cancer Institute, Department of Health, Education, and Welfare. Brookhaven National Laboratory is operated by Associated Universities, Inc., under Contract DE-AC02-76CH00016 with the United States Department of Energy. Supported in part by Research Grant 5 R01 CA 18332, National Cancer Institute, Department of Health, Education, and Welfare.

² To whom requests for reprints should be addressed.

Received 11/26/79. Accepted 2/13/80.

This article has been cited by other articles:

				A. M. Wilson and G. A. Reed Predominant 4-hydroxylation of estradiol by constitutive cytochrome P450s in the female ACI rat liver Carcinogenesis, February 1, 2001; 22(2): 257 - 263. [Abstract] [Full Text] [PDF]