Effects of selenium deficiency on Ca transport function of sarcoplasmic reticulum and lipid peroxidation in rat myocardium

Abstract

Two groups of weanling Sprague-Dawley rats were fed a low-selenium basal diet (Se 0.009 mg/kg) and the same diet supplemented with sodium selenite (Se 0.25 mg/kg), respectively, for 1, 2, and 3 months. At each feeding time, the Ca(2+)-ATPase activity, Ca2+ uptake rate and the capacity of Ca2+ uptake in isolated cardiac sacroplasmic reticulum from the Se-deficient rats were decreased significantly compared to those from the Se-supplemented rats, the contents of lipid peroxide in postmitochondrial supernatant and isolated sarcoplasmic reticulum from the Se-deficient rats were significantly higher than that from Se-supplemented rats. Compared to the Se-supplemented rats, the cytosolic glutathione peroxidase activity in Se-deficient rats decreased significantly. In addition, significant linear negative correlations of lipid peroxide in postmitochondrial supernatant to sarcoplasmic reticular Ca(2+)-ATPase activity, Ca2+ uptake rate and to whole blood selenium concentration were observed. The results suggest that the enhancement of lipid peroxidation via the depressed glutathione peroxidase activity might be responsible for the decrease of Ca(2+)-ATPase and Ca2+ uptake activities in sarcoplasmic reticulum in Se-deficient animals.

Diets deficient in selenium and vitamin E affect plasma lipoprotein and apolipoprotein concentrations in the rat

“…between Se and vitamin E is well known, and the metabolism of one of these is influenced by the other (Fisher &manger, 1977). It has been demonstrated that the oxidative damage in many tissues is more severe during double Se and vitamin E deficiency than with deficiency of either antioxidant alone (Arthur et al 1988;You-Zhen et al 1993;Lee & Csallany, 1994;Kuo et al 1995). Additionally, Se and vitamin E may have important roles in biological processes of importance for the cardiovascular system that do not necessarily relate to their antioxidant function (Arthur et al 1993;Dutta-Roy et al 1994).…”