Tudurí E, Beiroa D, Porteiro B, López M, Diéguez C, Nogueiras R. Acute but not chronic activation of brain glucagon-like peptide-1 receptors enhances glucose-stimulated insulin secretion in mice.
Diabetes Obes Metab 2015;
17:789-99. [PMID:
25962313 DOI:
10.1111/dom.12488]
[Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 04/24/2015] [Accepted: 05/03/2015] [Indexed: 01/15/2023]
Abstract
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.
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