Acute but not chronic activation of brain glucagon-like peptide-1 receptors enhances glucose-stimulated insulin secretion in mice

Diabetes Obes Metab. 2015 Aug;17(8):789-99. doi: 10.1111/dom.12488. Epub 2015 Jun 25.


Aim: To investigate the role of brain glucagon-like peptide-1 (GLP-1) in pancreatic β-cell function.

Methods: To determine the role of brain GLP-1 receptor (GLP-1R) on β-cell function, we administered intracerebroventricular (i.c.v.) infusions of GLP-1 or the specific GLP-1 antagonist exendin-9 (Ex-9), in both an acute and a chronic setting.

Results: We observed that acute i.c.v. GLP-1 infusion potentiates glucose-stimulated insulin secretion (GSIS) and improves glucose tolerance, whereas central GLP-1R blockade with Ex-9 impaired glucose excursion after a glucose load. Sustained activation of central nervous system GLP-1R, however, did not produce any effect on either GSIS or glucose tolerance. Similarly, ex vivo GSIS performed in islets from mice chronically infused with i.c.v. GLP-1 resulted in no differences compared with controls. In addition, in mice fed a high-fat diet we observed that acute i.c.v. GLP-1 infusion improved glucose tolerance without changes in GSIS, while chronic GLP-1R activation had no effect on glucose homeostasis.

Conclusions: Our results indicate that, under non-clamped conditions, brain GLP-1 plays a functional neuroendocrine role in the acute regulation of glucose homeostasis in both lean and obese rodents.

Keywords: central nervous system; exendin-9; glucagon-like peptide 1; glucose metabolism; islets; β cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Glucose / analysis
  • Blood Glucose / metabolism
  • Brain / metabolism*
  • Diet, High-Fat
  • Glucagon-Like Peptide 1 / administration & dosage
  • Glucagon-Like Peptide 1 / pharmacology*
  • Glucagon-Like Peptide-1 Receptor / antagonists & inhibitors
  • Glucagon-Like Peptide-1 Receptor / metabolism*
  • Glucose / administration & dosage
  • Homeostasis / drug effects
  • Incretins / administration & dosage
  • Incretins / pharmacology
  • Infusions, Intraventricular
  • Insulin / metabolism*
  • Insulin Secretion
  • Insulin-Secreting Cells / drug effects
  • Insulin-Secreting Cells / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL


  • Blood Glucose
  • Glucagon-Like Peptide-1 Receptor
  • Incretins
  • Insulin
  • Glucagon-Like Peptide 1
  • Glucose