Involvement of endogenous glucagon-like peptide-1(7-36) amide on glycaemia-lowering effect of oligofructose in streptozotocin-treated rats

J Endocrinol. 2005 Jun;185(3):457-65. doi: 10.1677/joe.1.06100.


We have evaluated the influence of oligofructose (OFS), a fermentable dietary fibre, on glucose homeostasis, insulin production and intestinal glucagon-like peptide-1 (GLP-1) in streptozotocin-treated diabetic rats. Male Wistar rats received either i.v. streptozotocin (STZ; 40 mg/kg) or vehicle (CT); one week later, they were fed for 6 weeks with either the standard diet (STZ-CT), or with a diet containing 10% oligofructose (STZ-OFS); both diets were available ad libitum. In a second set of experiments (duration 4 weeks), a supplemental group of food-restricted rats (STZ-Res) receiving a similar intake as CT rats, was added. OFS improved glucose tolerance and reduced food intake as compared with STZ-CT rats in both the post-prandial state and after an oral glucose tolerance test. After 6 weeks, portal and pancreatic insulin concentrations were doubled in STZ-OFS rats. Food restriction improved these parameters when compared with STZ-CT rats, but to a lesser extent than in the STZ-OFS group. We have shown that OFS treatment increased portal and colonic GLP-1(7-36) amide levels and doubled colonic proglucagon and prohormone convertase 1 mRNA levels; both OFS and food restriction lowered ileal GLP-1(7-36) amide levels as compared with levels in STZ-CT rats. We propose that OFS, through its fermentation in the colon, promotes the expression and secretion of colonic peptides, namely GLP-1(7-36) amide, with beneficial consequences on glycaemia, insulin secretion and hyperphagia in diabetic rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / genetics
  • Animals
  • Blood Glucose / analysis*
  • Colon / chemistry
  • Colon / metabolism*
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / metabolism
  • Eating / drug effects
  • Fermentation
  • Food Deprivation
  • Glucagon / blood
  • Glucagon / genetics
  • Glucagon-Like Peptide 1
  • Glucagon-Like Peptides
  • Glucose Tolerance Test
  • Insulin / analysis
  • Insulin / blood
  • Islets of Langerhans / chemistry
  • Male
  • Oligosaccharides / therapeutic use*
  • Peptide Fragments / analysis
  • Peptide Fragments / blood*
  • Proglucagon
  • Proprotein Convertase 1 / genetics
  • Protein Precursors / blood
  • Protein Precursors / genetics
  • RNA, Messenger / analysis
  • Rats
  • Rats, Wistar
  • Reverse Transcriptase Polymerase Chain Reaction


  • Actins
  • Blood Glucose
  • Insulin
  • Oligosaccharides
  • Peptide Fragments
  • Protein Precursors
  • RNA, Messenger
  • oligofructose
  • glucagon-like peptide 1 (7-36)amide
  • Proglucagon
  • Glucagon-Like Peptides
  • Glucagon-Like Peptide 1
  • Glucagon
  • Proprotein Convertase 1