Abstract
Recent investigations suggest that vanilloid receptor-1 (VR1) immunoreactivity occurs in the intestine. We have determined and quantified this immunoreactivity in the myenteric plexus with respect to cholinergic and neurofilament protein-positive neurones. Guinea-pig and rat preparations were dual-labelled with specific antibodies raised in rabbit or goat against vanilloid receptor-1 and against other neurochemical markers. In the rat ileum, both vanilloid receptor antibodies were co-distributed, whereas in the guinea-pig ileum and colon, tertiary fibres were also detected with the goat antibody. In the guinea-pig, all vanilloid receptor-l-immunoreactive cell bodies were choline acetyltransferase-immunopositive (100%) and showed some immunoreactivity to neurofilament proteins (NFP-200 kDa (79%) or triplet (10.8%)) or calretinin. Immunoreactive fibres in the secondary plexus co-localised with calcitonin gene-related peptide (CGRP) and with substance P, calretinin and synapsin I in the tertiary plexus. Subpopulations of cholinergic neurones including sensory, interneuronal and secretory neurones express vanilloid receptor-1. Co-localisation with substance P and calretinin in fibres suggests that vanilloid receptor-1 may be expressed by excitatory motor neurones. The association of vanilloid receptors with calcitonin gene-related peptide and synaptic protein in fibres implies a role for vanilloid receptors in neurotransmitter/neuropeptide release. Although it is likely that at least some of the vanilloid receptor-bearing fibres originate in immunopositive myenteric soma, the origin of all these fibres cannot be identified in the present study. (C) 2002 Elsevier Science B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 61-71 |
Number of pages | 10 |
Journal | European Journal of Pharmacology |
Volume | 458 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2003 |
Keywords
- immunohistochemistry
- myenteric plexus-longitudinal muscle
- choline acetyltransferase
- capsaicin receptor
- confocal microscopy
- GENE-RELATED PEPTIDE
- NEUROCHEMICAL CLASSIFICATION
- SMALL-INTESTINE
- SENSORY NERVES
- ISOLATED ILEUM
- NITRIC-OXIDE
- DISTAL COLON
- CAPSAICIN
- NEURONS
- RELEASE