Spinal cord astrocyte P2X7Rs mediate the inhibitory effect of electroacupuncture on visceral hypersensitivity of rat with irritable bowel syndrome.

This study explored the role of P2X7 receptors in spinal cord astrocytes in the electroacupuncture-induced inhibition of visceral hypersensitivity (VH) in rats with irritable bowel syndrome (IBS). Visceral hypersensitivity of IBS was intracolonically induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). Visceromotor responses to colorectal distension (CRD-20,40,60,80 mmHg) and abdominal withdrawal reflex scoring (AWRs) were recorded after electroacupuncture at bilateral Zusanli (ST36) and Sanyinjiao (SP6) acupoints to evaluate the analgesic effect of electroacupuncture on visceral pain in rats with IBS. Fluorocitric acid (FCA), an astrocyte activity inhibitor, was injected intrathecally before electroacupuncture intervention and AWRs were recorded. Western blot and real-time qPCR were used to detect the expression of NMDA and P2X7 receptor to observe the regulation effect of electroacupuncture on NMDA receptor in the spinal cord of rats with visceral hypersensitivity. Intrathecal injection of P2X7 agonist or antagonist was administered before electroacupuncture treatment. To observe the effect of P2X7 receptor in spinal astrocytes on the inhibition of visceral hyperalgesia by electroacupuncture, the changes of AWR score, NMDA receptor in the spinal cord, and GFAP expression in astrocytes were detected. Inflammation of the colon had basically subsided at day 21 post-TNBS; persistent visceral hypersensitivity could be suppressed by electroacupuncture. This analgesic effect could be inhibited by FCA. The analgesic effect, downregulation of NMDA receptor NR1 subunit, and P2X7 protein of electroacupuncture were all reversed by FCA. P2X7 receptor antagonist A740003 can cooperate with EA to carry out analgesic effect in rats with visceral pain and downregulate the expression of NR1, NR2B, and GFAP in spinal dorsal horn. However, the P2X7 receptor agonist BzATP could partially reverse the analgesic effect of EA, inhibiting the downregulatory effect of EA on the expression of NR1, NR2B, and GFAP. These results indicate that EA may downregulate the expression of the NMDA receptor by inhibiting the P2X7 receptor in the spinal cord, thereby inhibiting spinal cord sensitization in IBS rats with visceral pain, in which astrocytes are an important medium.

Acupuncture and Moxibustion Inhibited Intestinal Epithelial-Mesenchymal Transition in Patients with Crohn's Disease Induced by TGF- ß 1/Smad3/Snail Pathway: A Clinical Trial Study.

OBJECTIVE: To explore whether acupuncture combined with moxibustion could inhibit epithelialmesenchymal transition in Crohn's disease by affecting the transforming growth factor ß 1 (TGF- ß 1)/Smad3/Snail pathway. METHODS: Sixty-three patients with Crohn's disease were randomly divided into an observation group (31 cases) receiving moxibustion at 43 °C combined with acupuncture, and a control group (32 cases) receiving moxibustion at 37 °C combined with sham acupuncture using a random number table. Patients were treated for 12 weeks. Crohn's Disease Activity Index (CDAI) was used to evaluate disease activity. Hematoxylin-eosin staining and transmission electron microscopy were utilized to observe the morphological and ultrastructural changes. Immunohistochemistry was used to detect the expression of transforming growth factor ß 1 (TGF-ß 1), T ß R1, T ß R2, Smad3, Snail, E-cadherin and fibronectin in intestinal mucosal tissues. RESULTS: The decrease of the CDAI score, morphological and ultrastructural changes were more significant in observation group. The expression levels of TGF- ß 1, Tß R2, Smad3, and Snail in the observation group were significantly lower than those before the treatment (P<0.05 or P<0.01). After treatment, the expression levels of TGF-ß 1, TßR2, and Snail in the observation group were significantly lower than those in the control group (all P<0.05); compared with the control group, the expression of fibronectin in the observation group was significantly decreased, and the expression of E-cadherin was significantly increased (all P<0.05). CONCLUSIONS: Moxibustion at 43 °C combined with acupuncture may suppress TGF-ß 1/Smad3/Snail pathway-mediated epithelial-mesenchymal transition of intestinal epithelial cells in Crohn's disease patients by inhibiting the expression levels of TGF-ß 1, Tß R2, Smad3, and Snail. (Registration No. ChiCTR-IIR-16007751).

Long-term effect of moxibustion on irritable bowel syndrome with diarrhea: a randomized clinical trial.

BACKGROUND: Moxibustion is increasingly used for treatment of irritable bowel syndrome (IBS). This study investigated the long-term effects of moxibustion for IBS with diarrhea (IBS-D). METHODS: Patients with IBS-D were assigned to receive moxibustion or sham moxibustion (52 each, 3× per week, 6 weeks) and were followed up to 24 weeks. The acupoints were bilateral ST25 and ST36, body surface temperatures at acupoints were 43°C ± 1°C and 37°C ± 1°C for the moxibustion and sham groups, respectively. Primary outcome was changes in IBS Adequate Relief (IBS-AR) from baseline to 6 weeks. Secondary outcomes included the following: IBS symptom severity scale (IBS-SSS), Bristol stool form scale (BSS), IBS quality of life (IBS-QOL), and Hospital Anxiety and Depression Scale (HADS). RESULTS: Based on an intention-to-treat analysis, the rate of IBS-AR in the moxibustion group was significantly higher than the sham group at 6 weeks (76.9% versus 42.3%; p < 0.001); the mean decrease of total IBS-BSS score in the moxibustion group was lower than that of the sham group (-116.9 versus -61.5; p < 0.001), both of which maintained throughout the follow-up period. Five specific domains of the IBS-SSS were lower in the moxibustion group than the sham, throughout (p < 0.001). At week 6, the rate of reduction >50 points in IBS-SSS of the treatment group was significantly higher than that of the sham (p < 0.001), which persisted throughout the follow-up period. Similar long-lasting improvements were observed in BSS, stool frequency, and stool urgency (p < 0.001). Improvements of IBS-QOL and HADS were comparable between the groups. CONCLUSIONS: Moxibustion treatment benefits the long-term relief of symptoms in IBS-D patients. TRIAL REGISTRATION: Clinical trials.gov (NCT02421627). Registered on 20 April 2015.

Herb-Partitioned Moxibustion Improves Crohn's Disease-Associated Intestinal Fibrosis by Suppressing the RhoA/ROCK1/MLC Pathway.

BACKGROUND AND AIMS: Intestinal fibrosis is one of the severe and common complications of Crohn's disease (CD), but the etiology and pathogenesis remain uncertain. The study intended to examine whether the effect of herb-partitioned moxibustion on rats with CD-associated intestinal fibrosis is associated with the RhoA/ROCK1/MLC pathway. METHODS: All experimental rats were randomly allocated into the normal control group (NC), model control group (MC), and herb-partitioned moxibustion group (HPM). Intestinal fibrosis was established in rats with CD by repeated rectal administrations of 2,4,6-trinitrobenzenesulfonic acid (TNBS). Herb-partitioned moxibustion was applied at the Qihai (CV6) and Tianshu (ST25) acupoints once daily for 10 days in the HPM group. In this study, histological changes were examined by hematoxylin and eosin (HE) staining; then, Masson's trichrome staining was used to assess the degree of fibrosis in each group. Experimental methods of immunohistochemistry, western blotting, and real-time PCR were applied to detect the levels of α-SMA, collagen III, RhoA, ROCK1, and p-MLC. Moreover, the double immunofluorescent staining for the colocalization of both α-SMA and ROCK1 was performed. RESULTS: Contrasted with the normal controls, the collagen deposition and fibrosis scores were increased in colonic tissue of model rats, and HPM decreased the collagen deposition and fibrosis scores. The protein of α-SMA and collagen III in the MC group exceeds that of the NC group; HPM decreased the expression of α-SMA and collagen III in rats with intestinal fibrosis. Similarly, the expression of RhoA, ROCK1, and p-MLC in model rats was obviously increased compared with normal controls; the expression of RhoA, ROCK1, and p-MLC was decreased after HPM. The coexpression of α-SMA and ROCK1 in rats with intestinal fibrosis was higher than normal rats. CONCLUSION: HPM improves CD-associated intestinal fibrosis by suppressing the RhoA/ROCK1/MLC pathway.

[Effect of acupuncture-moxibustion on negative emotions and plasma tryptophan metabolism in patients with Crohn's disease at active stage].

OBJECTIVE: To observe the effect of acupuncture-moxibustion on negative emotions and plasma tryptophan (Trip)-kynurenine (Kyn) metabolism in the patients with Crohn's disease (CD) at the mild and moderate active stage. METHODS: A total of 66 CD patients were randomized into an observation group (33 cases, 1 case dropped off) and a control group (33 cases, 2 cases dropped off). In the observation group, acupuncture was applied in combination with moxibustion. In the control group, the sham-acupuncture was used in combination with sham-moxibustion. In both of the observation group and the control group, acupuncture was applied to Zhongwan (CV 12), Shangjuxu (ST 37), Sanyinjiao (SP 6), Gongsun (SP 4), Hegu (LI 4), Quchi (LI 11), Taixi (KI 3) and Taichong (LR 3), and moxibustion was applied to Tianshu (ST 25) and Zusanli (ST 36). The treatment was given once every two days, 3 times a week, totally for 12 weeks. Separately, before and after treatment, the score of the hospital anxiety-depression scale (HADS) and the score of intestinal core symptoms (degree of abdominal pain and frequency of diarrhea) were observed in the patients of the two groups. The concentration of plasma indoleamine 2,3-dioxygenase 1 (IDO1) and the ratios of Kyn/Trp, QuinA/Kyn, KynA/Kyn and KynA/QuinA were compared between the two groups. RESULTS: Compared with before treatment, the scores of HADS-A and HADS-D in the observation group and the score of HADS-A in the control group were all reduced after treatment (P<0.01, P<0.05). The scores of abdominal pain degree in the two groups and score of diarrhea frequency in the observation group were all reduced after treatment (P<0.001). After treatment, the reducing ranges of the score of HADS-A and the scores of abdominal pain degree and diarrhea frequency in the observation group were all larger than the control group (P<0.01, P<0.05). Compared with before treatment, the plasma IDO1 concentration in the two groups and the ratios of plasma Kyn/Trp and QuinA/Kyn in the observation group were all reduced after treatment (P<0.001, P<0.05, P<0.01), the ratios of plasma KynA/Kyn and KynA/QuinA were increased after treatment in the observation group (P<0.05, P<0.01). After treatment, the changes in IDO1 concentration and the ratios of plasma QuinA/Kyn and KynA/QuinA in the observation were larger than the control group (P≤0.01, P<0.05). In the observation group, the difference in the ratio of plasma KynA/Kyn before and after treatment was negatively related to the improvement value of HADS-D (r =-0.67, P<0.05). After treatment, plasma IDO1 concentration was positively related to HADS-A in the observation group (r =0.65, P<0.05). CONCLUSION: Acupuncture and moxibustion relieve the negative emotions of anxiety and depression in CD patients at mild and moderate active stage, which is probably related to the regulation of plasma Trp-Kyn metabolic pathway.

P2X3 Receptor in Primary Afferent Neurons Mediates the Relief of Visceral Hypersensitivity by Electroacupuncture in an Irritable Bowel Syndrome Rat Model.

BACKGROUND: Electroacupuncture (EA) has been confirmed effectiveness in the treatment of irritable bowel syndrome (IBS), and P2X3 receptors in the peripheral and central neurons participate in the acupuncture-mediated relief of the visceral pain in IBS. OBJECTIVE: To reveal the neurobiological mechanism that P2X3 receptor of colonic primary sensory neurons in the dorsal root ganglia of the lumbosacral segment is involved in the alleviation of visceral hypersensitivity by EA in an IBS rat model. METHODS: The IBS chronic visceral pain rat model was established according to the method of Al-Chaer et al. EA at the bilateral He-Mu points, including ST25 and ST37, was conducted for intervention. The behavioral studies, histopathology of colon, electrophysiology, immunofluorescence histochemistry, and real-time polymerase chain reaction assays were used to observe the role of P2X3 receptor in the colon and related DRG in relieving visceral hypersensitivity by EA. RESULTS: EA significantly reduced the behavior scores of the IBS rats under different levels (20, 40, 60, 80 mmHg) of colorectal distention stimulation and downregulated the expression levels of P2X3 receptor protein and mRNA in colon and related DRG of the IBS rats. EA also regulated the electrical properties of the membranes, including the resting membrane potential, rheobase, and action potential of colon-associated DRG neurons in the IBS rats. CONCLUSION: EA can regulate the P2X3 receptor protein and mRNA expression levels in the colon and related DRG of IBS rats with visceral pain and then regulate the excitatory properties of DRG neurons.

Electroacupuncture Improves IBS Visceral Hypersensitivity by Inhibiting the Activation of Astrocytes in the Medial Thalamus and Anterior Cingulate Cortex.

OBJECTIVE: To explore whether the effect of electroacupuncture (EA) on visceral hypersensitivity (VH) in rats with irritable bowel syndrome (IBS) is related to the changes of astrocyte activation in the medial thalamus (MT) and anterior cingulate cortex (ACC). METHOD: Male Sprague-Dawley rats were randomly divided into the normal control (NC) group, model control (MC) group, electroacupuncture (EA) group, and fluorocitrate (FCA) group. A model of visceral hypersensitivity was established by neonatal colorectal irritation. In the EA group, needles were inserted into the skin at the Tianshu (ST25) and Shangjuxu (ST37) acupoints, once a day for 7 days. The FCA group received intrathecal injection of FCA on the 1st, 4th, and 7th days. Visceral hypersensitivity was evaluated by the abdominal withdrawal reflex (AWR), and glial fibrillary acidic protein (GFAP) mRNA and protein levels in the MT and ACC were detected by real-time PCR, immunohistochemistry, and western blots. RESULTS: The AWR score in the MC group was significantly higher than in the NC group, and EA and FCA reduced the AWR score of VH rats. GFAP mRNA and protein levels in the MT and ACC of rats in the MC group were significantly increased compared with the NC group. After either electroacupuncture or fluorocitrate, GFAP mRNA and protein levels in the MT and ACC were both clearly reduced. CONCLUSION: Electroacupuncture alleviates IBS visceral hypersensitivity by inhibiting the activation of astrocytes in the MT and ACC.

Effect of herb-partitioned moxibustion on dopamine levels and dopamine receptor 1 expression in the colon and central nervous system in rats with Crohn's disease.

OBJECTIVE: To observe the effect of herb-partitioned moxibustion at the Tianshu (ST 25) and Qihai (CV 6) acupoints in rats with Crohn's disease, and explore the underlying mechanism from dopamine (DA) and dopamine receptor 1 (D1R) in the colon, spinal dorsal horn and hypothalamus. METHODS: The rats were randomly divided into the normal, model (CD), herb-partitioned moxibustion (Mox) and mesalazine (Mesa) groups. Damage in the colons was scored and observed by hematoxylin and eosin staining. DA and D1R protein expression in the colonic mucosa were detected by immunohistochemistry. The concentrations of DA and D1R in the spinal dorsal horn and hypothalamus were measured by enzyme-linked immunosorbent assay, and D1R mRNA expression was evaluated by quantitative real-time polymerase chain reaction. RESULTS: In the colon, compared with the normal group, DA, D1R protein expressions and D1R mRNA expression were significantly higher in the model group, while decreased in the Mox group and the Mesa group. In the spinal dorsal horn and hypothalamus, compared with the normal group, the concentrations of DA and D1R, and the D1R mRNA expressions were significantly higher in the model group, and decreased in the Mox group and the Mesa group. CONCLUSION: Herb-partitioned moxibustion at the Tianshu (ST 25) and Qihai (CV 6) acupoints relieved ulceration in CD rats, the underlying mechanism maybe relative with the regulation of DA and D1R in the colon, spinal dorsal horn and hypothalamus by moxibustion.

Comparison of the analgesic effects between electro-acupuncture and moxibustion with visceral hypersensitivity rats in irritable bowel syndrome.

AIM: To observe whether there are differences in the effects of electro-acupuncture (EA) and moxibustion (Mox) in rats with visceral hypersensitivity. METHODS: EA at 1 mA and 3 mA and Mox at 43 °C and 46 °C were applied to the Shangjuxu (ST37, bilateral) acupoints in model rats with visceral hypersensitivity. Responses of wide dynamic range neurons in dorsal horns of the spinal cord were observed through the extracellular recordings. Mast cells (MC) activity in the colons of rats were assessed, and 5-hydroxytryptamine (5-HT), 5-hydroxytryptamine 3 receptor (5-HT3R) and 5-HT4R expressions in the colons were measured. RESULTS: Compared with normal control group, responses of wide dynamic range neurons in the dorsal horn of the spinal cord were increased in the EA at 1 mA and 3 mA groups (1 mA: 0.84 ± 0.74 vs 2.73 ± 0.65, P < 0.001; 3 mA: 1.91 ± 1.48 vs 6.44 ± 1.26, P < 0.001) and Mox at 43 °C and 46 °C groups (43 °C: 1.76 ± 0.81 vs 4.14 ± 1.83, P = 0.001; 46 °C: 5.19 ± 2.03 vs 7.91 ± 2.27, P = 0.01). MC degranulation rates and the expression of 5-HT, 5-HT3R and 5-HT4R in the colon of Mox 46 °C group were decreased compared with model group (MC degranulation rates: 0.47 ± 0.56 vs 0.28 ± 0.78, P < 0.001; 5-HT: 1.42 ± 0.65 vs 7.38 ± 1.12, P < 0.001; 5-HT3R: 6.62 ± 0.77 vs 2.86 ± 0.88, P < 0.001; 5-HT4R: 4.62 ± 0.65 vs 2.22 ± 0.97, P < 0.001). CONCLUSION: The analgesic effects of Mox at 46 °C are greater than those of Mox at 43 °C, EA 1 mA and EA 3 mA.

Neurobiological Mechanism of Acupuncture for Relieving Visceral Pain of Gastrointestinal Origin.

It is currently accepted that the neural transduction pathways of gastrointestinal (GI) visceral pain include the peripheral and central pathways. Existing research on the neurological mechanism of electroacupuncture (EA) in the treatment of GI visceral pain has primarily been concerned with the regulation of relevant transduction pathways. The generation of pain involves a series of processes, including energy transduction of stimulatory signals in the sensory nerve endings (signal transduction), subsequent conduction in primary afferent nerve fibers of dorsal root ganglia, and transmission to spinal dorsal horn neurons, the ascending transmission of sensory signals in the central nervous system, and the processing of sensory signals in the cerebral cortex. Numerous peripheral neurotransmitters, neuropeptides, and cytokines participate in the analgesic process of EA in visceral pain. Although EA has excellent efficacy in the treatment of GI visceral pain, the pathogenesis of the disease and the analgesic mechanism of the treatment have not been elucidated. In recent years, research has examined the pathogenesis of GI visceral pain and its influencing factors and has explored the neural transduction pathways of this disease.

Effects of electroacupuncture on corticotropin-releasing hormone in rats with chronic visceral hypersensitivity.

AIM: To investigate the effect of electroacupuncture on corticotropin-releasing hormone (CRH) in the colon, spinal cord, and hypothalamus of rats with chronic visceral hypersensitivity. METHODS: A rat model of chronic visceral hypersensitivity was generated according to the internationally accepted method of colorectal balloon dilatation. In the 7(th) week after the procedure, rats were randomly divided into a model group (MG), electroacupuncture group (EA), and sham electroacupuncture group (S-EA). After treatment, the abdominal withdrawal reflex (AWR) score was used to assess the behavioral response of visceral hyperalgesia. Immunohistochemistry (EnVision method), ELISA, and fluorescence quantitative PCR methods were applied to detect the expression of CRH protein and mRNA in the colon, spinal cord, and hypothalamus. RESULTS: The sensitivity of the rats to the colorectal distension stimulus applied at different strengths (20-80 mmHg) increased with increasing stimulus strength, resulting in increasing AWR scores in each group. Compared with NG, the AWR score of MG was significantly increased (P < 0.01). After conducting EA, the AWR scores of the rats were decreased compared with MG rats. The relative expression of CRH mRNA in the colon, spinal cord, and hypothalamus of MG rats was significantly increased compared with NG rats (P < 0.01). CRH mRNA in the colon and spinal cord of EA and S-EA rats was decreased to varying degrees (P > 0.05) compared with normal rats (NG). However, the decrease in EA compared with MG rats was statistically significant (P < 0.01). The average optical density of CRH expression in the colon of the MG rats was significantly enhanced compared with NG (P < 0.05), while the average optical density of CRH expression in the EA and S-EA rats was significantly decreased compared with MG rats (P < 0.01, P < 0.05, respectively). Compared with MG rats, the CRH concentration in the spinal cord of EA rats was significantly reduced (P < 0.01), but there was no significant change in S-EA rats (P > 0.05). CONCLUSION: Electroacupuncture at the Shangjuxu acupoint was able to significantly reduce the visceral hypersensitivity in rats, and regulated the expression of CRH protein and mRNA in the colon, spinal cord and hypothalamus at different levels, playing a therapeutic role in this model of irritable bowel syndrome.

Mechanisms underlying the analgesic effect of moxibustion on visceral pain in irritable bowel syndrome: a review.

Irritable bowel syndrome (IBS) is a functional bowel disorder that causes recurrent abdominal (visceral) pain. Epidemiological data show that the incidence rate of IBS is as high as 25%. Most of the medications may lead to tolerance, addiction and toxic side effects. Moxibustion is an important component of traditional Chinese medicine and has been used to treat IBS-like abdominal pain for several thousand years in China. As a mild treatment, moxibustion has been widely applied in clinical treatment of visceral pain in IBS. In recent years, it has played an irreplaceable role in alternative medicine. Extensive clinical studies have demonstrated that moxibustion for treatment of visceral pain is simple, convenient, and inexpensive, and it is being accepted by an increasing number of patients. There have not been many studies investigating the analgesic mechanisms of moxibustion. Studies exploring the analgesic mechanisms have mainly focused on visceral hypersensitivity, brain-gut axis neuroendocrine system, and immune system. This paper reviews the latest developments in moxibustion use for treatment of visceral pain in IBS from these perspectives. It also evaluates potential problems in relevant studies on the mechanisms of moxibustion therapy to promote the application of moxibustion in the treatment of IBS.

Randomized controlled trial: moxibustion and acupuncture for the treatment of Crohn's disease.

AIM: To evaluate the clinical efficacy and safety of acupuncture and moxibustion for the treatment of active Crohn's disease (CD). METHODS: Ninety-two patients were equally and randomly divided into the treatment group and received herb-partitioned moxibustion combined with acupuncture, and the control group received wheat bran-partitioned moxibustion combined with superficial acupuncture. The patients received three treatment sessions per week for 12 wk and were followed up for 24 wk. The main outcome was evaluated using the CD Activity Index (CDAI) score, and the secondary outcomes were evaluated using laboratory indicators such as hemoglobin (HGB), C-reactive protein (CRP), erythrocyte sedimentation rate, quality-of-life, endoscopic ratings, and intestinal histology scores. RESULTS: The CDAI scores of both the treatment and control groups were significantly reduced after treatment compared with those measured before treatment. However, the degree of improvement in the treatment group was significantly greater than that of the control group. The improvement in symptoms in patients of the treatment group was sustained at follow-up, whereas that of the control group was not. The overall efficacy of the treatment was significantly greater than that of the control. Both groups demonstrated significant improvements in quality-of-life ratings after treatment, but the improvement was significantly greater in the treatment group than in the control group. In addition, the patients in the treatment group showed significantly increased HGB and significantly decreased CRP levels and histopathological scores at the end of treatment, whereas the control group did not exhibit significant changes. CONCLUSION: Moxibustion with acupuncture provided significant therapeutic benefits in patients with active CD beyond the placebo effect and is therefore an effective and safe treatment for active CD.

Electroacupuncture at He-Mu points reduces P2X4 receptor expression in visceral hypersensitivity.

Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) was reported to improve visceral hypersensitivity in rats. Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity in irritable bowel syndrome. Results showed that abdominal withdrawal reflex scores noticeably increased after model establishment. Simultaneously, P2X4 receptor immureactivity significantly increased in the colon and spinal cord. Electroacupuncture and pinaverium bromide therapy both markedly decreased abdominal withdrawal reflex scores in rats with visceral hypersensitivity, and significantly decreased P2X4 receptor immunoreactivity in the colon and spinal cord. These data suggest that electroacupuncture treatment can improve visceral hypersensitivity in rats with irritable bowel syndrome by diminishing P2X4 receptor immunoreactivity in the colon and spinal cord.

Electroacupuncture diminishes P2X2 and P2X3 purinergic receptor expression in dorsal root ganglia of rats with visceral hypersensitivity.

Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) can improve visceral hypersensitivity in rats. Colorectal distension was used to establish a rat model of chronic visceral hypersensitivity. Immunohistochemistry was used to detect P2X2 and P2X3 receptor expression in dorsal root ganglia from rats with chronic visceral hypersensitivity. Results demonstrated that abdominal withdrawal reflex scores obviously increased following establishment of the model, indicating visceral hypersensitivity. Simultaneously, P2X2 and P2X3 receptor expression increased in dorsal root ganglia. After bilateral electroacupuncture at Shangjuxu and Tianshu, abdominal withdrawal reflex scores and P2X2 and P2X3 receptor expression decreased in rats with visceral hypersensitivity. These results indicated that electroacupuncture treatment improved visceral hypersensitivity in rats with irritable bowel syndrome by reducing P2X2 and P2X3 receptor expression in dorsal root ganglia.