THE SYNERGISTIC EFFECTS OF VITAMIN-E AND SELENIUM IN IRON-OVERLOADED MOUSE HEARTS

OBJECTIVES: To determine whether supplementation with vitamin E and se lenium can improve myocardial antioxidant defenses in iron-overloaded mouse hearts. INTERVENTIONS: Iron-overload state was created in B6D2F1 mice (n = 20) by daily injection of iron dextran (5 mg intraperitonea lly/mouse) for four weeks. The mice were also simultaneously randomly assinged to receive vitamin E (alpha-tocopherol acetate, 40 mg intrape ritoneally, n = 5), selenium (sodium selenite, 1 part/million orally, n = 5), both (vitamin E + selenium, n = 5) or iron-only treatment (n = 5). The hearts were harvested for determination of selenium concentra tion and glutathione peroxidase activity. In a subsequent study, 15 B6 D2F1 mice were randomly assigned to receive daily injections of iron ( n = 5) or iron and combined antioxidant treatment (vitamin E + seleniu m, n = 5), or to serve as controls (n = 5) for four weeks. The hearts were harvested for determination of total iron concentrations. MAIN RE SULTS: Significantly greater concentrations of heart selenium and glut athione peroxidase activity were observed in groups supplemented with both agents, as opposed to iron-only treated or single supplemented mi ce. Significantly lower concentrations of iron were found in controls and in those receiving combined iron and antioxidant treatment (vitami n E + selenium) than in iron-only treated mice. CONCLUSIONS: Vitamin E and selenium function synergistically in the myocardium to provide im portant antioxidant defenses in iron-overload states, including increa sed concentrations of selenium, increased glutathione peroxidase activ ity and decreased concentrations of iron.