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Cholera toxin-sensitive neurons in guinea pig submucosal plexus
M M Jiang1, A Kirchgessner, M D Gershon
1Vollum Institute, Oregon Health Sciences University, Portland 97201.
The American Journal of Physiology
|January 1, 1993
Summary
Cholera toxin (CT) activates specific neurons in the gut. These neurons, containing vasoactive intestinal peptide (VIP), may increase intestinal secretions and blood flow.
Area of Science:
- Neurogastroenterology
- Molecular Biology
Background:
- Cholera toxin (CT) is known to increase intestinal secretions.
- The role of enteric neurons in CT-induced secretion is not fully understood.
Purpose of the Study:
- To investigate the role of enteric neurons in cholera toxin's effects on intestinal secretion.
- To identify specific neuronal populations targeted by CT.
Main Methods:
- Retrograde labeling of mucosal nerve terminals using the B subunit of CT (B-CT) in guinea pig small intestine.
- Intracellular recordings from submucosal neurons during CT superfusion.
- Colocalization studies using Fluorogold (FG) to trace nerve pathways.
Main Results:
- All and only vasoactive intestinal peptide (VIP)-positive neurons exhibited B-CT binding.
- CT selectively depolarized VIP-containing neurons.
- Some VIP neurons innervate both mucosal and arteriolar sites.
Conclusions:
- VIP-containing neurons in the submucosal plexus possess CT binding sites and are activated by CT.
- CT may stimulate intestinal secretion by activating vasodilator nerves, enhancing mucosal perfusion.