Related Experiment Videos
VIP receptors on canine submucosal synaptosomes
1Division of Physiology and Pharmacology, McMaster University, Hamilton, Ontario, Canada.
Peptides
|November 1, 1993
Summary
Researchers identified vasoactive intestinal peptide (VIP) receptors in canine small intestine submucosa, suggesting VIP modulates nerve signaling. These findings are crucial for understanding gut neurobiology and potential therapeutic targets.
Area of Science:
- Gastroenterology
- Neuroscience
- Pharmacology
Background:
- Vasoactive intestinal peptide (VIP) is a key neuropeptide involved in gastrointestinal functions.
- Understanding VIP receptor characteristics in the enteric nervous system is essential for elucidating gut regulation.
Purpose of the Study:
- To characterize the binding properties of VIP receptors in canine small intestine submucosal synaptosomes.
- To determine the molecular nature and signaling pathway of the VIP receptor.
Main Methods:
- Radioligand binding assays using [125I]VIP.
- Saturation, competition, and kinetic binding studies.
- GTP-gamma-S and cholera toxin assays to assess G-protein coupling.
- Molecular weight determination via cross-linking.
Main Results:
- Identified both high- and low-affinity VIP binding sites.
- Evidence suggests the receptor is coupled to a G-protein, likely Gs.
- VIP analogs indicate the N-terminal region is critical for binding affinity.
- Cross-linking revealed a single peptide of approximately 60,000 M(r).
Conclusions:
- The study characterized a VIP receptor in canine enteric nerves, distinct from PACAP receptors.
- VIP likely modulates mediator release from enteric nerve endings.
- Findings provide insights into VIPergic neurotransmission in the gut.