Warming Moxibustion Relieves Chronic Visceral Hyperalgesia in Rats: Relations to Spinal Dynorphin and Orphanin-FQ System

Li Qi,Tao Yi,Lu-Yi Wu,Huan-Gan Wu,Xiao-Peng Ma,Chen Zhao,Hui-Rong Liu,Xi-Ru Liu,Yin Shi

doi:10.1155/2013/920675

Abstract

As a twin therapy of acupuncture in traditional Chinese medicine, moxibustion has shown its effects in relieving abdominal pain in irritable bowel syndrome (IBS) patients and IBS rat models, but its mechanisms are largely unknown. In this paper, we determined the role of spinal dynorphin and orphanin-FQ system in analgesic effect of warming moxibustion (WM) on chronic visceral hyperalgesia (CVH) in IBS-like rat model. Here, we show that (1) repeated WM at bilateral ST25 and ST37 acupoints markedly attenuated the abdominal withdrawal reflex scores in CVH rats; (2) intrathecal administration of κ receptor antagonist prior to WM significantly attenuated the WM analgesia and dynorphinA (1-17) enhanced the WM analgesia. WM significantly reinforced the upregulation of spinal dynorphin mRNA/protein and κ receptor mRNA levels in CVH rats; (3) intrathecal administration of orphanin-FQ receptor antagonist prior to WM significantly attenuated the WM analgesia and orphanin-FQ enhanced the WM analgesia. WM reinforced the upregulation of spinal orphanin-FQ mRNA/protein and orphanin-FQ receptor mRNA levels in CVH rats. These results suggest that moxibustion may relieve CVH at least in part by activating spinal dynorphin and orphanin-FQ system.

Highlights

Irritable bowel syndrome (IBS) is a highly prevalent chronic gastrointestinal dysfunctional disease
We reported that warming moxibustion (WM) treatment could alleviate chronic visceral hyperalgesia (CVH) in irritable bowel syndrome (IBS)-like rats by suppressing hypothalamic corticotrophin-releasing-hormone level [11], which provides the evidence that the analgesic effect of moxibustion may be associated with the central nervous system (CNS)
We investigated whether the spinal dynorphin-κ system could produce inhibitory effect on CVH by a behavioral test

Summary

Introduction

Irritable bowel syndrome (IBS) is a highly prevalent chronic gastrointestinal dysfunctional disease. Chronic visceral hyperalgesia (CVH) has been identified as an important aspect of IBS pathophysiology, and abdominal pain is a primary factor related to the quality of life in IBS patients [1, 2]. The treatment of visceral pain remains a significant challenge [3]. Moxibustion, an important component of traditional Chinese medicine, is a therapeutic method in which burning moxa produces thermal stimulation to the human body, and it affects the function of the meridians and acupoints to prevent and treat the disease [4]. Moxibustion has been adopted as an analgesic method for thousands of years in China and other AsiaN countries and is still frequently used in the present clinical practice because of its advantages of safety, effectiveness, and no side effects [5,6,7].

Methods

Results

Conclusion