title: Oral Administration of Collagen Hydrolysates Improves Glucose Tolerance in Normal Mice Through GLP-1-Dependent and GLP-1-Independent Mechanisms.
abstract: The aim of this study was to evaluate the antidiabetic properties of collagen hydrolysates (CHs). CHs exhibited dipeptidyl peptidase-IV inhibitory activity and stimulated glucagon-like-peptide-1 (GLP-1) secretion in vitro. We also determined whether CHs improve glucose tolerance in normal mice. Oral administration of CHs suppressed the glycemic response during the oral and intraperitoneal glucose tolerance tests (OGTT and IPGTT), but the effects were weaker in IPGTT than in OGTT. CHs had no effect on the gastric emptying rate. A pretreatment with the GLP-1 receptor antagonist, exendin 9-39 (Ex9), partially reversed the glucose-lowering effects of CHs, but only when coadministered with glucose. CHs administered 45 min before the glucose load potentiated the glucose-stimulated insulin secretion. This potentiating effect on insulin secretion was not reversed by the pretreatment with Ex9, it appeared to be enhanced. These results suggest that CHs improve glucose tolerance by inhibiting intestinal glucose uptake and enhancing insulin secretion, and also demonstrated that GLP-1 was partially involved in the inhibition of glucose uptake, but not essential for the enhancement of insulin secretion.
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Iba
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Koji
authors.initials: K
authors.lastname: Yokoi
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Itsuka
authors.initials: I
authors.lastname: Eitoku
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Masaki
authors.initials: M
authors.lastname: Goto
authors.affiliation: 2 Nitta Gelatin Incorporated , Peptide Division, Futamata, Yao, Osaka, Japan .
authors.forename: Seiko
authors.initials: S
authors.lastname: Koizumi
authors.affiliation: 2 Nitta Gelatin Incorporated , Peptide Division, Futamata, Yao, Osaka, Japan .
authors.forename: Fumihito
authors.initials: F
authors.lastname: Sugihara
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oyama
authors.affiliation: 1 Department of Life Science, Faculty of Science and Engineering, Setsunan University , Neyagawa, Osaka, Japan .
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshimoto
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D023681:Cichlids; D003094:Collagen / Q000494:pharmacology* / Q000627:therapeutic use; D018819:Dipeptidyl Peptidase 4 / Q000097:blood; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000494:pharmacology; D029941:Fish Proteins / Q000494:pharmacology* / Q000627:therapeutic use; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D018149:Glucose Intolerance / Q000097:blood* / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D008810:Mice, Inbred C57BL; D011492:Protein Hydrolysates / Q000494:pharmacology* / Q000627:therapeutic use; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D029941:Fish Proteins; D007004:Hypoglycemic Agents; D007328:Insulin; D011492:Protein Hydrolysates; D052216:Glucagon-Like Peptide 1; D003094:Collagen; D018819:Dipeptidyl Peptidase 4
keywords: DPP-IV; blood glucose; collagen peptides; diabetes; dietary supplements; functional foods; insulin; intestinal glucose uptake