Iron Overload Secondary to Selenium -Deficiency Changes the Electrocardiographic Pattern in Rats

Abstract

Selenium (Se) deficiency causes an abnormal hematological profile in animals, and an increased accumulation of iron in various organs. The aim of this study was to investigate whether excess iron has a direct effect on cardiac muscle, leading to increased abnormalities in heart functions, as observed in Keshan disease. Male Wistar rats fed either of following Torula yeast-based Se-deficient [Se (-) ] or Se-adequate [Se (+)] (containing 0.1 ppm Se as sodium selenite) diet for 8 weeks. The animals were injected intramuscularly with iron-dextran (totaling 500mg of iron) . Iron concentrations in the liver and spleen as well as the percentage of transferrin saturation were significantly higher in Se (-) rats without iron overload than in Se (+) rats without iron overload. However,. iron concentrations in the sera, hearts and kidneys did not significantly differ between the groups. Se (-) and Se (+) rats with iron overload showed a 2 to 40-fold increase in iron concentrations of all tissues examined, and 2-fold increase in the percentage of transferrin saturation, regardless of Se status. Se (-) rats with and without iron overload and Se (+) with iron overload all showed a greater T-wave height, a depression of S-T segment and a shallow S-wave. There was a 2-fold increase in T-wave height in Se (-) rats with iron overload compared with Se (-) rats without iron overload. The conclusion derived is that electrocardiogram is abnormal in Se deficiency, probably due to increased myocardial iron deposits.