Elsevier

Molecular Metabolism

Volume 2, Issue 1, February 2013, Pages 47-53
Molecular Metabolism

Brief Report
The role of sodium-coupled glucose co-transporter 3 in the satiety effect of portal glucose sensing

https://doi.org/10.1016/j.molmet.2012.11.003Get rights and content
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Abstract

Portal vein glucose sensors detect variations in glycemia to induce a nervous signal that influences food intake and glucose homeostasis. Previous experiments using high infusions of glucose suggested a metabolic sensing involving glucose transporter 2 (GLUT2). Here we evaluated the afferent route for the signal and candidate molecules for detecting low glucose fluxes. Common hepatic branch vagotomy did not abolish the anorectic effect of portal glucose, indicating dorsal transmission. GLUT2-null mice reduced their food intake in response to portal glucose signal initiated by protein-enriched diet. A similar response of Trpm5-null mice and portal infusions of sweeteners also excluded sugar taste receptors. Conversely, infusions of alpha-methylglucose, but not 3-O-methylglucose, decreased food intake, while phlorizin prevented the effect of glucose. This suggested sensing through SGLT3, which was expressed in the portal area.

From these results we propose a finely tuned dual mechanism for portal glucose sensing that responds to different physiological conditions.

Abbreviations

(3-O-MDG)
3-O-methyl-d-glucopyranose
(5-HT)
5-hydroxytryptamin/serotonin
(αMDG)
α-methylglucopyranoside
(EGP)
endogenous glucose production
(GFAP)
glial fibriallary acidic protein
(GLP1)
glucagon-like peptide 1
(G6PC)
glucose-6-phosphatase catalytic subunit
(GLUT)
glucose transporter
(GAPDH)
glyceraldehyde-3-phosphate dehydrogenase
(PGP9.5)
protein gene product 9.5
(PED)
protein-enriched diet
(SED)
starch-enriched diet
(SGLT)
sodium glucose co-transporter
(Trpm5)
transient receptor potential melastin 5

Keywords

Glucose sensing
Portal vein
SGLTs
Peripheral nervous signal
Glucose metabolism
Food intake

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