Brief Article
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Nov 7, 2009; 15(41): 5211-5217
Published online Nov 7, 2009. doi: 10.3748/wjg.15.5211
Effect of electro-acupuncture on substance P, its receptor and corticotropin-releasing hormone in rats with irritable bowel syndrome
Xiao-Peng Ma, Lin-Ying Tan, Yun Yang, Huan-Gan Wu, Bin Jiang, Hui-Rong Liu, Ling Yang
Xiao-Peng Ma, Lin-Ying Tan, Yun Yang, Huan-Gan Wu, Bin Jiang, Hui-Rong Liu, Ling Yang, Shanghai Institute of Acupuncture-Moxibustion and Meridian, Shanghai 200030, China
Author contributions: Wu HG and Ma XP designed the research; Ma XP, Tan LY, Yang Y, Jiang B and Liu HR performed the experiments; Ma XP and Yang Y analyzed the data; Ma XP, Yang Y, Tan LY and Yang L wrote and revised the manuscript; Wu HG supervised the whole research and edited the manuscript.
Supported by Open Fund of Key Laboratory of Acupuncture Combined with Medication (Nanjing University of TCM), Ministry of Education, No. KJA200809; Shanghai Rising-Star Program, No. 08QA14064; Shanghai Leading Academic Discipline Project, No. S30304
Correspondence to: Huan-Gan Wu, Professor, Shanghai Institute of Acupuncture-Moxibustion and Meridian, Shanghai 200030, China. wuhuangan@126.com
Telephone: +86-21-64644238 Fax: +86-21-64644238
Received: August 10, 2009
Revised: August 31, 2009
Accepted: September 7, 2009
Published online: November 7, 2009
Abstract

AIM: To investigate the effect and mechanism of electro-acupuncture (EA) at ST25 and ST37 on irritable bowel syndrome (IBS) of rats.

METHODS: A total of 21 male Sprague-Dawley rats were randomly divided into normal group, model group and EA group. A rat model of IBS was established by constraining the limbs and distending the colorectum of rats. Rats in EA group received bilateral EA at ST25 and ST37 with a sparse and intense waveform at a frequency of 2/50 Hz for 15 min, once a day for 7 d as a course. Rats in normal and model groups were stimulated by distending colorectum (CR). An abdominal withdrawal reflex (AWR) scoring system was used to evaluate improvements in visceral hypersensitivity. Toluidine blue-improved method, immunohistochemistry and radioimmunoassay were used to observe mucosal mast cells (MC), changes of substance P (SP) and substance P receptor (SPR) in colon and change of corticotropin-releasing hormone (CRH) in hypothalamus.

RESULTS: The threshold of visceral sense was significantly lower in model group than in normal group, and significantly higher in EA group than in model group. The number of mucosal MC was greater in model group than in normal group and significantly smaller in EA group than in model group. The CRH level in hypothalamus of rats was significantly higher in model group than in normal group, which was remarkably decreased after electro-acupuncture treatment. The SP and SPR expression in colon of rats in model group was decreased after electro-acupuncture treatment.

CONCLUSION: EA at ST25 and ST37 can decrease the number of mucosal MC and down-regulate the expression of CRH in hypothalamus, and the expression of SP and SPR in colon of rats with IBS.

Keywords: Electro-acupuncture; Corticotropin-releasing hormone; Irritable bowel syndrome; Substance P; Substance P receptor