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EMBO Rep. 2015 Oct;16(10):1299-307. doi: 10.15252/embr.201540492. Epub 2015 Aug 19.

Glucagon signalling in the dorsal vagal complex is sufficient and necessary for high-protein feeding to regulate glucose homeostasis in vivo.

Author information

1
Toronto General Research Institute & Department of Medicine UHN, Toronto, Canada Department of Physiology, University of Toronto, Toronto Canada.
2
Toronto General Research Institute & Department of Medicine UHN, Toronto, Canada.
3
Toronto General Research Institute & Department of Medicine UHN, Toronto, Canada Department of Physiology, University of Toronto, Toronto Canada Department of Medicine, University of Toronto, Toronto Canada Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada tony.lam@uhnres.utoronto.ca.

Abstract

High-protein feeding acutely lowers postprandial glucose concentration compared to low-protein feeding, despite a dichotomous rise of circulating glucagon levels. The physiological role of this glucagon rise has been largely overlooked. We here first report that glucagon signalling in the dorsal vagal complex (DVC) of the brain is sufficient to lower glucose production by activating a Gcgr-PKA-ERK-KATP channel signalling cascade in the DVC of rats in vivo. We further demonstrate that direct blockade of DVC Gcgr signalling negates the acute ability of high- vs. low-protein feeding to reduce plasma glucose concentration, indicating that the elevated circulating glucagon during high-protein feeding acts in the brain to lower plasma glucose levels. These data revise the physiological role of glucagon and argue that brain glucagon signalling contributes to glucose homeostasis during dietary protein intake.

KEYWORDS:

brain; glucagon; glucose homeostasis; protein‐feeding

PMID:
26290496
PMCID:
PMC4766461
DOI:
10.15252/embr.201540492
[Indexed for MEDLINE]
Free PMC Article

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