Effect of insulin in combination with selenium on Irs/PI3K-mediated GLUT4 expression in cardiac muscle of diabetic rats.

BACKGROUND Oral administration of selenium is an effective treatment for diabetes in animal models. However, selenium exerts these effects at high doses and several toxic effects are produced. Low doses of selenium are relatively safe but are unable to elicit any antidiabetic effect. OBJECTIVES The present study explored the prospect of using low doses of insulin in combination with selenium to evaluate their antidiabetic effect, and to evaluate their effect on IRS-1, PI3K and GLUT4 levels in cardiac muscle of diabetic rats. MATERIALS AND METHODS Diabetic rats were treated with insulin, selenium, and insulin and selenium in combination for four weeks. The effect of these antidiabetic compounds was examined on general physiological parameters and distribution of IRS-1, PI3K and GLUT4 in cardiac muscle by immunoblotting and immunohistochemistry. RESULTS Insulin in combination with selenium could significantly revive normoglycemia, and restore the disturbances in IRS-1, PI3K and GLUT4 levels in cardiac muscle. Treatment with insulin was only partially effective in the restoration of diabetic alterations. CONCLUSION The treatment of diabetic rats with combined doses of insulin and selenium was most effective in controlling glycaemia, and remarkably restored GLUT4 distribution by IRS-1/PI3K-dependent pathway in cardiac muscle of diabetic rat.