NeuroanatomyMuscarinic M2 acetylcholine receptor distribution in the guinea-pig gastrointestinal tract
Section snippets
Experimental procedures
Adult male Hartley guinea-pigs aged 4–6 weeks and weighing 250–400 g (Japan SLC, Hamamatsu, Shizuoka, Japan) were used in this study. All animal experiments were carried out in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and the Guidelines for Animal Experiments, University of Fukui Faculty of Medical Sciences. All efforts were made to minimize the number of animals used and their suffering. All guinea-pigs were anesthetized with an i.p.
Results
M2 receptor-like immunoreactivity (M2R-LI) was observed associated with smooth muscle cells in the gastrointestinal tract (Fig. 1, Table 1). The external muscle layers, except the esophagus, were immunoreactive for M2 receptor. The intensity of immunoreactivity was higher in the stomach, small intestine, cecum, distal colon and rectum than in the proximal colon. Distinct immunoreaction was also observed in the muscularis mucosae in the pylorus, colon and rectum.
Discussion
In this study, we obtained evidence that muscarinic M2 acetylcholine receptor-like immunoreactivity (M2R-LI) is distributed in the smooth muscle cells and interstitial cells of Cajal in the musculature of the guinea-pig gastrointestinal tract. These findings are the first evidence of M2 receptor distribution on a morphological level.
Presence of M2 receptor in the smooth muscle tissue is known by immunoprecipitation studies, ligand binding studies and PCR studies (Dorje et al 1991, Eglen et al
Conclusion
In summary, we examined the immunohistochemical distribution of the muscarinic M2 acetylcholine receptor, which is the major muscarinic receptor subtype expressed by smooth muscle tissues in the guinea-pig gastrointestinal tract. M2R-LI was mainly observed as associated with smooth muscle cells in the gastrointestinal tract. M2R-LI in smooth muscle cells was distributed throughout the cell membrane associated with caveolae. Interstitial cells of Cajal in the small intestine DMP and in the
Acknowledgment
We thank Prof. N. W. Bunnett (University of California, San Francisco) for the gift of the anti-neurokinin 1 receptor (#94168). This work was supported by Grant-in-Aid for Scientific Research from Japan Society for Promotion of Science.
References (40)
- et al.
Transfer of M2 muscarinic acetylcholine receptors to clathrin-derived early endosomes following clathrin-independent endocytosis
J Biol Chem
(2002) - et al.
Subtypes of the muscarinic receptor in smooth muscle
Life Sci
(1997) - et al.
Dynamic targeting of the agonist-stimulated m2 muscarinic acetylcholine receptor to caveolae in cardiac myocytes
J Biol Chem
(1997) Types of neurons in the enteric nervous system
J Auton Nerv Syst
(2000)- et al.
Muscarinic receptor subtypes in human and rat colon smooth muscle
Biochem Pharmacol
(1992) Immunological localization of m1-m5 muscarinic acetylcholine receptors in peripheral tissues and brain
Life Sci
(1993)- et al.
Trafficking of M2 muscarinic acetylcholine receptors
J Biol Chem
(1999) - et al.
Interstitial cells in the musculature of the gastrointestinal tractCajal and beyond
Int Rev Cytol
(2003) - et al.
Immunohistochemical demonstration of the NK1 tachykinin receptor on muscle and epithelia in guinea pig intestine
Gastroenterology
(2001) Muscarinic receptors in developing rat colon
Eur J Pharmacol
(1996)
Loss of enteric motor neurotransmission in the gastric fundus of Sl/Sld mice
J Physiol (Lond)
Enteric motor and interneuronal circuits controlling motility
Neurogastroenterol Motil
International Union of Pharmacology. XVII. Classification of muscarinic acetylcholine receptors
Pharmacol Rev
Immunological detection of muscarinic receptor subtype proteins (m1-m5) in rabbit peripheral tissues
Mol Pharmacol
Muscarinic receptor subtypes and smooth muscle function
Pharmacol Rev
Molecular markers expressed in cultured and freshly isolated interstitial cells of Cajal
Am J Physiol Cell Physiol
Evolving concepts in G protein-coupled receptor endocytosisthe role in receptor desensitization and signaling
Pharmacol Rev
Characterization of antisera specific to NK1, NK2, and NK3 neurokinin receptors and their utilization to localize receptors in the rat gastrointestinal tract
J Neurosci
Muscular innervation of the proximal duodenum of the guinea pig
Arch Histol Cytol
Interstitial cells of Cajal are functionally innervated by excitatory motor neurones in the murine intestine
J Physiol (Lond)
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