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Updated: Aug 8, 2026
Immunostaining to Visualize Murine Enteric Nervous System Development
Published on: April 29, 2015
Ultrastructural simultaneous localization of vasoactive intestinal polypeptide immunoreactivity and the
Insights
Vasoactive intestinal polypeptide (VIP) and acetylcholine (ACh) coexist in rat pancreatic nerve endings, suggesting they jointly regulate hormone secretion. This co-localization indicates a complex interplay in pancreatic endocrine function.
Area of Science:
- Neuroendocrinology
- Cell Biology
- Gastroenterology
Background:
- The endocrine pancreas regulates blood glucose through hormone secretion.
- Neural regulation of pancreatic hormone release involves neurotransmitters like acetylcholine (ACh).
- Vasoactive intestinal polypeptide (VIP) is implicated in modulating pancreatic function.
Purpose of the Study:
- To investigate the ultrastructural co-localization of VIP and ACh-like cations in the rat endocrine pancreas.
- To determine the relationship between VIP-immunoreactive nerve endings and pancreatic endocrine cells and blood vessels.
- To elucidate the potential roles of VIP and ACh in regulating pancreatic hormonal secretion.
Main Methods:
- Immunoperoxidase cytochemistry for VIP detection.
- Ionic fixation of ACh using silicotungstic acid.
- Ultrastructural analysis of nerve endings in the rat endocrine pancreas.
Main Results:
- VIP and ACh-like cations were ultrastructurally co-localized in rat pancreatic nerve endings.
- VIP-immunoreactive nerve terminals containing ACh were primarily associated with endocrine cells (A, B, D cells).
- Nerve endings without VIP but with ACh were found near endocrine cells and blood vessels.
Conclusions:
- VIP and ACh likely act together to modulate hormonal secretion from pancreatic endocrine cells.
- The findings suggest a potential role for VIP and ACh in neuroendocrine regulation of the pancreas.
- ACh may also influence endothelial cell function in pancreatic blood vessels.
Abstract:
The ultrastructural co-localization of vasoactive intestinal polypeptide (VIP) and acetylcholine (ACh)-like cation was demonstrated in the rat endocrine pancreas. Immunoperoxidase cytochemical procedure for the detection of VIP was followed by ionic fixation of ACh by silicotungstic acid. All the VIP-immunoreactive nerve endings displayed punctiform precipitates revealing ACh-like cations in the small clear vesicles. Almost all the VIP-immunoreactive nerve terminals were in contact with endocrine A, B or D cells, but not in the close vicinity of blood vessels. Nerve endings devoid of VIP immunoreactivity but containing ACh-like cations were seen either in contact with endocrine cells or in close vicinity to blood vessels. These data suggest that VIP might modulate, concomitantly with ACh, the hormonal secretion of the endocrine pancreas, although the possibility of the neurosecretion of ACh and VIP into the blood vessels should not be excluded. ACh might also control some function of the endothelial cells of blood vessels.
