Giessener Elektronische Bibliothek

GEB - Giessener Elektronische Bibliothek

Novel aspects of cholinergic regulation of colonic ion transport

Bader, Sandra ; Diener, Martin

Originalveröffentlichung: (2015) Pharmacology Research & Perspectives 3(3):e00139 doi:10.1002/prp2.139
Zum Volltext im pdf-Format: Dokument 1.pdf (898 KB)

Bitte beziehen Sie sich beim Zitieren dieses Dokumentes immer auf folgende
URN: urn:nbn:de:hebis:26-opus-115296

Freie Schlagwörter (Englisch): choline , intestinal epithelium , ion transport , muscarinic receptors , nicotinic receptors
Sammlung: Open Access - Publikationsfonds
Universität Justus-Liebig-Universität GieĂźen
Institut: Institut für Veterinär-Physiologie und -Biochemie
Fachgebiet: Veterinärmedizin
DDC-Sachgruppe: Landwirtschaft
Dokumentart: Aufsatz
Sprache: Englisch
Erstellungsjahr: 2015
Publikationsdatum: 30.06.2015
Kurzfassung auf Englisch: Nicotinic receptors are not only expressed by excitable tissues, but have been identified in various epithelia. One aim of this study was to investigate the expression of nicotinic receptors and their involvement in the regulation of ion transport across colonic epithelium. Ussing chamber experiments with putative nicotinic agonists and antagonists were performed at rat colon combined with reverse transcription polymerase chain reaction (RT-PCR) detection of nicotinic receptor subunits within the epithelium. Dimethylphenylpiperazinium (DMPP) and nicotine induced a tetrodotoxin-resistant anion secretion leading to an increase in short-circuit current (Isc) across colonic mucosa. The response was suppressed by the nicotinic receptor antagonist hexamethonium. RT-PCR experiments revealed the expression of a2, a4, a5, a6, a7, a10, and ß4 nicotinic receptor subunits in colonic epithelium. Choline, the product of acetylcholine hydrolysis, is known for its affinity to several nicotinic receptor subtypes. As a strong acetylcholinesterase activity was found in colonic epithelium, the effect of choline on Isc was examined. Choline induced a concentration-dependent, tetrodotoxin-resistant chloride secretion which was, however, resistant against hexamethonium, but was inhibited by atropine. Experiments with inhibitors of muscarinic M1 and M3 receptors revealed that choline-evoked secretion was mainly due to a stimulation of epithelial M3 receptors. Although choline proved to be only a partial agonist, it concentration-dependently desensitized the response to acetylcholine, suggesting that it might act as a modulator of cholinergically induced anion secretion. Thus the cholinergic regulation of colonic ion transport – up to now solely explained by cholinergic submucosal neurons stimulating epithelial muscarinic receptors – is more complex than previously assumed.
Lizenz: Lizenz-Logo  Creative Commons - Namensnennung - Nicht-kommerziell