FACTORS INFLUENCING THE ANTI-CARCINOGENIC EFFICACY OF SELENIUM IN DIMETHYLBENZ[A]ANTHRACENE-INDUCED MAMMARY TUMORIGENESIS IN RATS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (7) , 2683-2686
Abstract
The effect of Se supplementation on dimethylbenz[a]anthracene[DMBA]-induced mammary tumorigenesis was studied. Female Sprague-Dawley rats were fed either a 5 or 25% corn oil diet, denoted as low fat (LF) or high fat (HF), respectively. Se supplementation of LF and HF diets were begun at 21 days of age. In experiment 1, rats (50 days of age) were given 5 mg of DMBA p.o. [orally] and were supplemented with 0.1 (adequate level), 0.5, 1.5 and 2.5 ppm Se (as sodium selenite) in the diet. The total number of tumors found was as follows (30 rats/group): 26, 23, 19 and 10, respectively, in the LF group; and 65, 66, 41 and 21, respectively, in the HF group. In experiment 2, rats (50 days of age) were given 10 mg DMBA and Se was added to the diets at 0.1, 2.5 and 5.0 ppm. Tumor yields were 71, 32 and 15, respectively, in the LF group and 135, 85 and 46, respectively, in the HF group. There was also a trend towards a longer latency period of tumor appearance with Se supplementation. High dietary Se levels are able to protect against mammary tumorigenesis but rats on a HF diet still develop more tumors than those on a LF diet at comparable Se supplementation.