Intestinal glucose-induced calcium-calmodulin kinase signaling in the gut-brain axis in awake rats

K. M. Vincent, J. W. Sharp, Helen E Raybould

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Background Lumenal glucose initiates changes in gastrointestinal (GI) function, including inhibition of gastric emptying, stimulation of pancreatic exocrine and endocrine secretion, and intestinal fluid secretion. Glucose stimulates the release of GI hormones and 5-hydroxytryptamine (5-HT), and activates intrinsic and extrinsic neuronal pathways to initiate changes in GI function. The precise mechanisms involved in luminal glucose-sensing are not clear; studying gut endocrine cells is difficult due to their sparse and irregular localization within the epithelium. Methods Here we show a technique to determine activation of gut epithelial cells and the gut-brain pathway in vivo in rats using immunohistochemical detection of the activated, phosphorylated, form of calcium-calmodulin kinase II (pCaMKII). Key Results Perfusion of the gut with glucose (60mg) increased pCaMKII immunoreactivity in 5-HT-expressing enterochromaffin (EC) cells, cytokeratin-18 immunopositive brush cells, but not in enterocytes or cholecystokinin-expressing cells. Lumenal glucose increased pCaMKII in neurons in the myenteric plexus and nodose ganglion, nucleus of the solitary tract, dorsal motor nucleus of the vagus and the arcuate nucleus. pCaMKII expression in neurons, but not in EC cells, was significantly attenuated by pretreatment with the 5-HT 3R antagonist ondansetron. Deoxynojirimycin, a selective agonist for the putative glucose sensor, sodium-glucose cotransporter-3 (SGLT-3), mimicked the effects of glucose with increased pCaMKII in ECs and neurons; galactose had no effect. Conclusions & Inferences The data suggest that native EC cells in situ respond to glucose, possibly via SGLT-3, to activate intrinsic and extrinsic neurons and thereby regulate GI function.

Original languageEnglish (US)
JournalNeurogastroenterology and Motility
Volume23
Issue number7
DOIs
StatePublished - Jul 2011

Fingerprint

Calcium-Calmodulin-Dependent Protein Kinases
Calcium
Glucose
Brain
Enterochromaffin Cells
Sodium-Glucose Transport Proteins
Neurons
Serotonin
Nodose Ganglion
Enteroendocrine Cells
Intestinal Secretions
Keratin-18
Gastrointestinal Hormones
Fluids and Secretions
Ondansetron
Myenteric Plexus
Arcuate Nucleus of Hypothalamus
Serotonin Antagonists
Solitary Nucleus
Enterocytes

Keywords

  • 5-HT3 receptor
  • Brush cell
  • Enterochromaffin cell
  • Sodium-glucose cotransporter 3

ASJC Scopus subject areas

  • Endocrine and Autonomic Systems
  • Gastroenterology
  • Physiology

Cite this

Intestinal glucose-induced calcium-calmodulin kinase signaling in the gut-brain axis in awake rats. / Vincent, K. M.; Sharp, J. W.; Raybould, Helen E.

In: Neurogastroenterology and Motility, Vol. 23, No. 7, 07.2011.

Research output: Contribution to journalArticle

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