Effects of selenium on 7,12-dimethylbenz(a)anthracene-induced mammary carcinogenesis and DNA adduct formation
The purpose of the present investigation was to determine the effects of dietary selenium deficiency or excess on 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary neoplasia in rats and to delineate whether selenium-mediated modification of mammary carcinogenesis was associated with changes in carcinogen:DNA adduct formation and activities of liver microsomal enzymes that are involved in xenobiotic metabolism. Female Sprague-Dawley rats were divided into three groups from weaning and were maintained on one of three synthetic diets designated as follows: selenium deficient (less than 0.02 ppm); selenium adequate (0.2 ppm); or selenium excess (2.5 ppm). For the DMBA binding and DNA adduct studies, rats were given a dose of (/sup 3/H)DMBA p.o. after 1 month on their respective diets. Results from the liver and the mammary gland indicated that neither selenium deficiency nor excess had any significant effect on the binding levels, which were calculated on the basis of total radioactivity isolated with the purified DNA. Furthermore, it was found that dietary selenium intake did not seem to affect quantitatively or qualitatively the formation of DMBA:DNA adducts in the liver. Similarly, in a parallel group of rats that did not receive DMBA, the activities of aniline hydroxylase, aminopyrine N-demethylase, and cytochrome c reductase were not significantly altered by dietary selenium levels. Concurrent with the above experiments, the effect of dietary selenium intake on carcinogenesis was also monitored. Results of this experiment indicated that selenium deficiency enhanced mammary carcinogenesis only when this nutritional condition was maintained in the postinitiation phase. Likewise, an excess of selenium intake inhibited neoplastic development only when this regimen was continued after DMBA administration.
- Research Organization:
- Roswell Park Memorial Inst., Buffalo, NY
- OSTI ID:
- 5975894
- Journal Information:
- Cancer Res.; (United States), Vol. 45:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BENZANTHRACENE
CARCINOGENESIS
TOXICITY
MAMMARY GLANDS
NEOPLASMS
SELENIUM
BIOLOGICAL EFFECTS
INTAKE
CHEMICAL BONDS
DNA
DNA ADDUCTS
HYDROXYLASES
LIVER
METABOLISM
NUTRITIONAL DEFICIENCY
OXIDOREDUCTASES
RATS
ADDUCTS
ANIMALS
AROMATICS
BODY
CONDENSED AROMATICS
DIGESTIVE SYSTEM
DISEASES
ELEMENTS
ENZYMES
GLANDS
HYDROCARBONS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PATHOGENESIS
RODENTS
SEMIMETALS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)
550201 - Biochemistry- Tracer Techniques