title: Novel glucagon-like peptide-1 (GLP-1) analog (Val8)GLP-1 results in significant improvements of glucose tolerance and pancreatic beta-cell function after 3-week daily administration in obese diabetic (ob/ob) mice.
abstract: This study evaluates the antidiabetic potential of an enzyme-resistant analog, (Val8)GLP-1. The effects of daily administration of a novel dipeptidyl peptidase IV-resistant glucagon-like peptide-1 (GLP-1) analog, (Val8)GLP-1, on glucose tolerance and pancreatic beta-cell function were examined in obese-diabetic (ob/ob) mice. Acute intraperitoneal administration of (Val8)GLP-1 (6.25-25 nmol/kg) with glucose increased the insulin response and reduced the glycemic excursion in a dose-dependent manner. The effects of (Val8)GLP-1 were greater and longer lasting than native GLP-1. Once-daily subcutaneous administration of (Val8)GLP-1 (25 nmol/kg) for 21 days reduced plasma glucose concentrations, increased plasma insulin, and reduced body weight more than native GLP-1 without a significant change in daily food intake. Furthermore, (Val8)GLP-1 improved glucose tolerance, reduced the glycemic excursion after feeding, increased the plasma insulin response to glucose and feeding, and improved insulin sensitivity. These effects were consistently greater with (Val8)GLP-1 than with native GLP-1, and both peptides retained or increased their acute efficacy compared with initial administration. (Val8)GLP-1 treatment increased average islet area 1.2-fold without changing the number of islets, resulting in an increased number of larger islets. These data demonstrate that (Val8)GLP-1 is more effective and longer acting than native GLP-1 in obese-diabetic ob/ob mice.
authors.affiliation: School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK. b.green@ulster.ac.uk
authors.forename: Brian D
authors.initials: BD
authors.lastname: Green
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Lavery
authors.forename: Nigel
authors.initials: N
authors.lastname: Irwin
authors.forename: Finbarr P M
authors.initials: FP
authors.lastname: O'harte
authors.forename: Patrick
authors.initials: P
authors.lastname: Harriott
authors.forename: Brett
authors.initials: B
authors.lastname: Greer
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Bailey
authors.forename: Peter R
authors.initials: PR
authors.lastname: Flatt
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D052216:Glucagon-Like Peptide 1 / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D018149:Glucose Intolerance / Q000188:drug therapy* / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology; D008297:Male; D051379:Mice; D008820:Mice, Obese
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D052216:Glucagon-Like Peptide 1