Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2017; 23(21): 3825-3831
Published online Jun 7, 2017. doi: 10.3748/wjg.v23.i21.3825
Corticotropin-releasing factor stimulates colonic motility via muscarinic receptors in the rat
Kyung-Jo Kim, Ki Bae Kim, Soon Man Yoon, Joung-Ho Han, Hee Bok Chae, Seon Mee Park, Sei Jin Youn
Kyung-Jo Kim, Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05535, South Korea
Ki Bae Kim, Soon Man Yoon, Joung-Ho Han, Hee Bok Chae, Seon Mee Park, Sei Jin Youn, Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Chungcheongbuk-do 28644, South Korea
Author contributions: Kim KJ and Youn SJ designed the research; Kim KJ, Kim KB, Yoon SM, Han JH, Chae HB and Park SM contributed substantially to the conception and design of the study, data acquisition and analysis and interpretation of the data; all the authors drafted the article and made critical revisions related to its intellectual content, and approved the final version to be published.
Institutional animal care and use committee statement: All experiments were approved by the Animal Care Committee of Chungbuk National University.
Conflict-of-interest statement: To the best of our knowledge, no conflict of interest exists.
Data sharing statement: The dataset is available from the corresponding author at sjyoun@chungbuk.ac.kr.
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: Sei Jin Youn, MD, Department of Internal Medicine, Chungbuk National University College of Medicine, 410 Seong bong-ro, Heungduk-gu, Cheongju, Chungcheongbuk-do 28644, South Korea. sjyoun@chungbuk.ac.kr
Telephone: +82-43-2696357 Fax: +82-43-2733252
Received: November 23, 2016
Peer-review started: November 25, 2016
First decision: December 19, 2016
Revised: January 18, 2017
Accepted: April 13, 2017
Article in press: April 13, 2017
Published online: June 7, 2017
Abstract
AIM

To measure exogenous corticotropin-releasing factor (CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility.

METHODS

The isolated vascularly-perfused rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers in the proximal and distal colon. At first, exogenous CRF was administered in a stepwise manner and the concentration of CRF yielding maximal colonic motility was selected. After recording basal colonic motility, hexamethonium, phentolamine, propranolol, atropine and tetrodotoxin were infused into the isolated colon. Initially, only the test drug was infused; then, CRF was added. The motility index was expressed as percentage change over basal level.

RESULTS

Administration of 1.4, 14.4, 144 and 288 pmol/L CRF progressively increased colonic motility in the proximal and distal colon. Infusion of atropine or tetrodotoxin reduced CRF-induced motility of both the proximal and distal colon, whereas hexamethonium, phentolamine and propranolol had no effect.

CONCLUSION

CRF-induced colonic motility appears to be mediated by local cholinergic signaling via muscarinic receptors. Muscarinic receptors are potential targets for counteracting CRF-induced colonic hypermotility.

Keywords: Gastrointestinal motility, Rats, Stress, Colon, Corticotropin-releasing factor

Core tip: Corticotropin-releasing factor (CRF) has emerged as a key mediator of functional bowel disorders and the effects of stress and inflammation on the gastrointestinal tract. CRF-induced colonic motility is mediated by local cholinergic signaling via muscarinic receptors, and blocking muscarinic receptors is a potential way to prevent CRF-induced hypermotility of the colon.