ARS | Publication request: Obesity decreases serum selenium levels in DMBA-induced mammary tumor using Obese Zucker Rat Model

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 15, 2010
Publication Date: March 17, 2011
Citation: Hakkak, R., Zeng, H., Lacher, C.P., Johnson, L.K., Korourian, S. 2011. Obesity decreases serum selenium levels in DMBA-induced mammary tumor using Obese Zucker Rat Model. Federation of American Societies for Experimental Biology Conference. 25:977.12.

Technical Abstract: Recently, we reported that obese Zucker rats had increased susceptibility to DMBA-induced mammary tumors compared to lean Zucker rats. Several studies suggest that lower serum selenium may play an important role in increasing the risk of several types of cancers (e.g, colon, breast and prostate cancers). In the present study, we used this model to investigate whether serum selenium is affected by obesity. Lean and obese rats were sham operated or ovariectomized at age 40 days and were gavaged at age 50 days with 65 mg/kg DMBA. 51 to 57 rats for each group were weighed and palpated twice weekly for detection of mammary tumors and killed 135 later. The serum selenium was measured by graphite furnace atomic absorption spectrometry. At the end of the experiment, 36% of the obese ovariectomized (O/O) rats developed mammary tumors while lean ovariectomized (L/O) rats developed no mammary tumors (P<0.001). The Obese sham-operated (O/S) rats developed mammary tumors (59%) compared to 30% of the lean sham-operated (L/S) rats (P<0.05). The serum selenium was not affected significantly by ovariectomy but obesity decreased the serum selenium levels L/S and L/O (511 ± 71) vs. O/S and O/O (480 ± 145) (P<0.05). In summary, obesity decreases serum selenium levels using DMBA-induced mammary tumors Zucker rat model. These data suggest that serum selenium may play an important role in mammary carcinogenesis.