VARIABILITY IN THE DISTRIBUTION OF SELENIUM IN HEALTHY HEART-TISSUE MEASURED BY NEUTRON-ACTIVATION ANALYSIS

Chronic dietary deficiency of selenium has been shown to be associated with degenerative heart disease in production animals in the U.S. and in the human in parts of China. In the latter, subjects in the endemi c areas suffer high rates of a cardiomyopathy known as Keshan's Diseas e which is normally fatal in early adulthood and can be prevented, or reversed in its early stages, via selenium supplementation. Selenium a s the active moiety in the enzyme glutathione peroxidase, protects aga inst oxidative attack of cell membranes by peroxides formed during nor mal metabolism. In this study, we investigated the distribution of sel enium in healthy porcine and bovine heart tissue freshly collected at slaughter. The whole heart was perfused with DI water and carefully de -fatted. Representative samples of left and right atria and Ventricles and the interventricular septum were collected, lyophilized and homog enized prior to preparing replicate samples for analysis. Replicates w ere analyzed for selenium via an INAA scheme employing a 5, 15 and 25 second irradiation (phi(th) = 8.10(13) n.cm(-2).s(-1)), decay and real -time count (Se-77m, T-1/2 = 17.4 s), respectively, using high-resolut ion gamma-ray spectroscopy with Westphal pulse pile-up correction. Sel enium distribution will be discussed relative to differentiated functi on and oxygenation of the specific tissues.