Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pathophysiol. Aug 15, 2015; 6(3): 51-57
Published online Aug 15, 2015. doi: 10.4291/wjgp.v6.i3.51
Gut region-dependent alterations of nitrergic myenteric neurons after chronic alcohol consumption
Mária Bagyánszki, Nikolett Bódi
Mária Bagyánszki, Nikolett Bódi, Department of Physiology, Anatomy and Neuroscience, University of Szeged, 6726 Szeged, Hungary
Author contributions: Both of the authors contributed to this paper.
Supported by The János Bolyai Research Scholarship of the Hungarian Academy of Sciences (Mária Bagyánszki); by the Hungarian Scientific Research Fund, OTKA grant PD 108309 (Nikolett Bódi).
Conflict-of-interest statement: The authors have no conflict of interest related to the manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Mária Bagyánszki, PhD, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Közép fasor 52, 6726 Szeged, Hungary. bmarcsi@bio.u-szeged.hu
Telephone: +36-62-343103 Fax: +36-62-544149
Received: January 28, 2015
Peer-review started: February 1, 2015
First decision: March 6, 2015
Revised: March 27, 2015
Accepted: June 1, 2015
Article in press: June 2, 2015
Published online: August 15, 2015

Chronic alcohol abuse damages nearly every organ in the body. The harmful effects of ethanol on the brain, the liver and the pancreas are well documented. Although chronic alcohol consumption causes serious impairments also in the gastrointestinal tract like altered motility, mucosal damage, impaired absorption of nutrients and inflammation, the effects of chronically consumed ethanol on the enteric nervous system are less detailed. While the nitrergic myenteric neurons play an essential role in the regulation of gastrointestinal peristalsis, it was hypothesised, that these neurons are the first targets of consumed ethanol or its metabolites generated in the different gastrointestinal segments. To reinforce this hypothesis the effects of ethanol on the gastrointestinal tract was investigated in different rodent models with quantitative immunohistochemistry, in vivo and in vitro motility measurements, western blot analysis, evaluation of nitric oxide synthase enzyme activity and bio-imaging of nitric oxide synthesis. These results suggest that chronic alcohol consumption did not result significant neural loss, but primarily impaired the nitrergic pathways in gut region-dependent way leading to disturbed gastrointestinal motility. The gut segment-specific differences in the effects of chronic alcohol consumption highlight the significance the ethanol-induced neuronal microenvironment involving oxidative stress and intestinal microbiota.

Keywords: Chronic ethanol consumption, Nitrergic myenteric neurons, Enteric nervous system, Nitric oxide synthase, Gut motility disorders, Intestinal microbiota

Core tip: Chronic ethanol administration causes neurodegeneration in the central nervous system. In the enteric nervous system neurodegeneration was not demonstrated, however alcohol-induced quantitative, functional and neurochemical changes of nitrergic myenteric neurons were observed in gut region-dependent way. These suggest that disturbed gastrointestinal transit characteristic to alcoholic patients due to an impairment of a nitric oxide-mediated descending inhibition during peristalsis. The better understanding of the effects of chronic ethanol administration on enteric neurons may reveal new targets for therapy.