Influences of high dietary fat and/or indomethacin on tumor proliferation and cell kinetics of 7,12-dimethylbenz(a)anthracene-induced mammary carcinomas in rats.

We investigated the effects of a high-fat diet and indomethacin on tumorigenesis, tumor proliferation and cell kinetics of 7,12-Dimethylbenz(a)anthracene (DMBA)--induced mammary carcinomas in Sprague-Dawley (SD) rats. Both the high-fat diet and indomethacin significantly stimulated tumor proliferation and cell kinetics, whereas tumorigenesis was significantly stimulated by the high-fat diet but it was significantly inhibited by indomethacin. Moreover, switching the animals from the high-fat diet with or without indomethacin to the low-fat diet suppressed tumor proliferation and cell kinetics. It can therefore be concluded that either a high-fat diet or indomethacin stimulates tumor proliferation in DMBA--induced mammary carcinoma in SD rats.