Department of Biological and Environmental Sciences, Faculty of Science, Beirut Arab University, Beirut, Lebanon.
Biochem Genet. 2012 Dec;50(11-12):922-35. doi: 10.1007/s10528-012-9532-2. Epub 2012 Sep 16.
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.
硒和 exendin-4 通过未知机制发挥抗糖尿病作用。在此，我们研究了它们对链脲佐菌素诱导的糖尿病大鼠肝脏中胰高血糖素样肽-1 受体 (GLP-1R)、胰岛素受体底物-1 (IRS-1) 和 Raf-1 表达的影响。糖尿病大鼠每天两次腹膜内注射 exendin-4（0.03μg/kg 体重）或用 5ppm 硒作为亚硒酸钠饮用水治疗 4 周。硒和 exendin-4 均可降低糖尿病大鼠的高血糖。糖尿病诱导导致肝脏中 GLP-1R 水平降低，IRS-1 和 Raf-1 水平升高。与糖尿病大鼠相比，用硒或 exendin-4 治疗糖尿病大鼠可导致肝脏中 GLP-1R 水平升高，IRS-1 和 Raf-1 水平降低。因此，硒和 exendin-4 的抗糖尿病作用涉及它们对肝脏中 GLP-1R、IRS-1 和 Raf-1 水平的影响。
