Gender differences are related to the manner in which the heart responds to chronic and acute stress conditions of physiological and pathological nature. Depending on dose,
sodium selenite acts as an
antioxidant proven to have beneficial effects in several pathological conditions G. Drasch, J. Schopfer, and G. N. Schrauzer,
Selenium/
cadmium ratios in human prostates: indicators of
prostate cancer risk of smokers and nonsmokers, and relevance to the
cancer protective effects of
selenium, Biol.
Trace Element Res. 103(2), 103-107 (2005); R. G. Kasseroller and G. N. Schrauzer, Treatment of secondary
lymphedema of the arm with physical decongestive
therapy and
sodium selenite: a review, Am. J. Ther. 7(4), 273-279 (2000); G. N. Schrauzer,
Anticarcinogenic effects of
selenium, Cell. Mol. Life Sci. 57(13-14), 1864-1873 (2000); I. S. Palmer and O. E. Olson, Relative toxicities of
selenite and
selenate in the
drinking water of rats, J. Nutr. 104(3), 306-314 (1974). To date, little is known about the gender-dependent direct effects of toxic doses of
selenite on electrophysiology of the cardiovascular system H. A. Schroeder and M. Mitchener,
Selenium and
tellurium in rats: effect on growth, survival and
tumors, J. Nutr. 101(11), 1531-1540 (1971); G. N. Schrauzer, The nutritional significance, metabolism and toxicology of
selenomethionine, Adv. Food Nutr. Res. 47, 73-112 (2003). In the present study, the effects of in vitro toxic concentrations of
sodium selenite ranging from 10-6 M to 10-3 M were tested on both male and female rat heart preparations. The toxic effects seen in an electrocardiogram and left ventricular pressure were dose and sex dependent at most of the tested concentrations. The present study clearly shows that at toxic doses, stress conditions are induced by
selenite, resulting in genderdependent modifications of the heart function. This modification is more pronounced in the contraction cascade of female rats. Males, on the other hand, had been much more affected in excitation-related parameters.