Effects of Selenium and Exendin-4 on Glucagon-Like Peptide-1 Receptor, IRS-1, and Raf-1 in the Liver of Diabetic Rats

• DOI: 10.1007/s10528-012-9532-2
• Publication Date: 2012-09-15T11:48:38Z
• Authors: Ghinwa M. Barakat; Mohamed E. Moustafa; Anwar B. Bikhazi
• Keywords: Blood Glucose; Male; 0301 basic medicine; 0303 health sciences; Blotting, Western; MAP Kinase Kinase Kinases; Glucagon-Like Peptide-1 Receptor; Diabetes Mellitus, Experimental; Rats; 3. Good health; Proto-Oncogene Proteins c-raf; Rats, Sprague-Dawley; Selenium; 03 medical and health sciences; Sodium Selenite; Liver; Insulin Receptor Substrate Proteins; Receptors, Glucagon; Animals; Exenatide; Hypoglycemic Agents; Insulin; RNA, Messenger; Peptides

Selenium and exendin-4 exert antidiabetic effects by unknown mechanisms. Herein, we investigated their effects on the expression of glucagon-like peptide-1 receptor (GLP-1R), insulin receptor substrate-1 (IRS-1), and Raf-1 in the livers of rats with streptozotocin-induced diabetes. Diabetic rats were injected intraperitoneally with exendin-4 (0.03 μg/kg body weight) twice daily or treated with 5 ppm selenium as sodium selenite in drinking water for 4 weeks. Both selenium and exendin-4 reduced the hyperglycemia in diabetic rats. Induction of diabetes mellitus resulted in decreased level of GLP-1R and increased levels of IRS-1 and Raf-1 in the liver. Treatment of diabetic rats with selenium or exendin-4 resulted in increased level of GLP-1R and decreased levels of IRS-1 and Raf-1 in the liver, compared with the levels in diabetic rats. Therefore, the antidiabetic actions of selenium and exendin-4 involve their effects on GLP-1R, IRS-1, and Raf-1 levels in the liver.