title: Effects of selenium and exendin-4 on glucagon-like peptide-1 receptor, IRS-1, and Raf-1 in the liver of diabetic rats.
abstract: 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.
authors.affiliation: Department of Biological and Environmental Sciences, Faculty of Science, Beirut Arab University, Beirut, Lebanon.
authors.forename: Ghinwa M
authors.initials: GM
authors.lastname: Barakat
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Moustafa
authors.forename: Anwar B
authors.initials: AB
authors.lastname: Bikhazi
mesh_terms: D000818:Animals; D001786:Blood Glucose; D015153:Blotting, Western; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D000077270:Exenatide; D000067757:Glucagon-Like Peptide-1 Receptor; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology; D055504:Insulin Receptor Substrate Proteins / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D019908:Proto-Oncogene Proteins c-raf; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018027:Receptors, Glucagon / Q000235:genetics / Q000378:metabolism*; D012643:Selenium / Q000378:metabolism / Q000494:pharmacology; D018038:Sodium Selenite / Q000008:administration & dosage / Q000494:pharmacology*; D013311:Streptozocin / Q000008:administration & dosage / Q000009:adverse effects; D013997:Time Factors; D014688:Venoms / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D007004:Hypoglycemic Agents; D007328:Insulin; D055504:Insulin Receptor Substrate Proteins; C526296:Irs1 protein, rat; D010455:Peptides; D012333:RNA, Messenger; D018027:Receptors, Glucagon; D014688:Venoms; D013311:Streptozocin; D000077270:Exenatide; D019908:Proto-Oncogene Proteins c-raf; C546782:Raf1 protein, rat; D020930:MAP Kinase Kinase Kinases; D012643:Selenium; D018038:Sodium Selenite