Selenium supplementation can protect cultured rat cardiomyocytes from hypoxia/reoxygenation damage

The possibility of enhancing glutathione peroxidase (GPx) activity and cytosolic total antioxidant activity (TAA) in normoxia and hypoxia/reoxygenation (H/R) by the supplementation of different concentrations of sodium selenite (SS) or selenomethionine (SM) was investigated in cultured rat cardiomyocytes. To assess the entity of oxidative stress due to H/R, levels of conjugated dienes containing lipids were determined. In normoxia, GPx activity and TAA increased in parallel with the increase in SS and SM supplementation. H/R did not influence GPx activity but lowered TAA; both SS and SM supplementations were effective in increasing GPx activity, the most effective concentration being 1 microM. At this SS and SM concentration, TAA returned to a normoxic value. Conjugated diene production, increased by H/R, was reduced by SS and SM supplementation, the 1 microM concentration appearing to be the most effective one. According to these data Se supplementation represents another possibility to counteract oxidative damage in the myocardium.