Effects of moxibustion on behaviors and tryptophan metabolism-related products in mice with irritable bowel syndrome / 针灸推拿医学（英文版）

Objective: To observe the effect of moxibustion on behaviors and related products of tryptophan (Trp) metabolism in the colon of mice with irritable bowel syndrome (IBS), and to explore the mechanism of moxibustion in the IBS treatment.Methods: Twenty-four mice were randomly divided into a normal group, a model group, a moxibustion group, and a probiotic group, with 6 mice in each group. The visceral pain model of IBS was established by enema with 2,4,6-trinitrobenzene sulfonic acid (TNBS) solution. Mice in the moxibustion group were treated with mild moxibustion at bilateral Zusanli (ST36), and those in the probiotic group were treated with probiotics such as Bifidobacterium by gavage. Abdominal withdrawal reflex (AWR) test, elevated plus-maze (EPM) test, and forced swimming test (FST) were performed after treatment. The expression levels of 5-hydroxytryptamine (5-HT) and tryptophan hydroxylase 1 (TPH1) in the colon were detected by immunofluorescence, and the expression levels of Trp, kynurenine (Kyn), and indole-2,3-oxygenase (IDO) in the colon were detected by enzyme-linked immunosorbent assay. Results: Compared with the normal group, the AWR scores were increased significantly in the model group under different pressure values (P<0.01), the open-arm staying time and open-arm entries in the EPM test were decreased significantly (P<0.01, P<0.05), the motionless time in the FST was increased significantly (P<0.01), and the expression levels of colonic Trp, TPH1, IDO, 5-HT, and Kyn were increased significantly (P<0.01) in the models. Compared with the model group, the AWR scores were differently decreased (P<0.05 or P<0.01), the open-arm entries in the EPM test were increased (P<0.05), the motionless times in the FST were decreased (P<0.05), and the colonic expression levels of Trp, TPH1, IDO, and 5-HT were decreased (P<0.01 or P<0.05) in the moxibustion and probiotic groups; the open-arm staying time was significantly increased in the moxibustion group (P<0.01), and the colonic expression level of Kyn was significantly decreased in the probiotic group (P<0.01). Conclusion: Moxibustion at Zusanli (ST36) improves visceral pain and pain mood and down-regulates the expression levels of colonic TPH1, IDO, Trp, 5-HT, and Kyn in IBS mice.

Mechanism of dexmedetomidine preconditioning on spinal cord analgesia in rats with functional chronic visceral pain

Purpose: To analyze the effect and mechanism of dexmedetomidine (DEX) analgesia pretreatment on functional chronic visceral pain in rats. Methods: Rats were divided into six groups: W1, W2, W3, W4, W5, and W6. The behavioral changes and electrophysiological indexes of rats in each group before and after DEX treatment were detected. Results: The levels of abdominal withdrawal reflex (AWR) in W5 and W6 groups were significantly lower than those in group W3, while the levels of thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) were significantly higher than those in group W3 (p < 0.05). The electromyographic signals of W1, W5, and W6 groups showed little fluctuation, while those of groups W2, W3, and W4 showed obvious fluctuation. TLR4 mRNA expression, IRF3, P65, and phosphorylation levels in W4, W5, and W6 groups were significantly lower than those in group W2 (p < 0.05). Conclusions: Dexmedetomidine epidural anesthesia pretreatment could significantly inhibit visceral pain response in rats with functional chronic visceral pain, and its mechanism was related to the activation of TLR4 in spinal dorsal horn tissue of rats and the activation inhibition of IRF3 and P65 in the downstream key signals.

Targeting GATA1 and p2x7r Locus Binding in Spinal Astrocytes Suppresses Chronic Visceral Pain by Promoting DNA Demethylation / 神经科学通报·英文版

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1-TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.

Regulatory effect of mild moxibustion on P2X3 receptors in spinal cord, anterior cingulate cortex and thalamic ventral posterolateral nucleus of rats with IBS visceral hyperalgesia / 针灸推拿医学（英文版）

Objective: To observe the therapeutic effect of mild moxibustion on irritable bowel syndrome (IBS) visceral hyperalgesiamodel rats and its regulatory effect on P2X3 receptors in the spinal cord, anterior cingutate cortex (ACC) and thalamic ventral posterolateral nucleus (VPL). Methods: Thirty 8-day-old newborn rats were randomly divided into a normal group (n=6) and a modeling group (n=24) according to the completely random number table method. Rats in the normal group were bred routinely, and those in the modeling group were subjected to preparing IBS chronic visceral hyperalgesia model using colorectal distention (CRD) in stimulation method. Rats successfully modelled were re-divided into a model group, a mild moxibustion group, a P2X3 receptor antagonist group, and a normal saline group according to the completely random number table method with 6 rats in each group. Rats in each group received corresponding interventions from the 37-day old, once a day for 7 consecutive days. Immunohistochemistry and Western blot assays were used to detect P2X3 protein expressions in the spinal cord, ACC and VPL of rats. Results: Under different intensities of CRD stimulation, the abdominal withdrawal reflex (AWR) scores of the model group were significantly increased versus the normal group (all P<0.05); the AWR scores of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group (all P<0.01). The P2X3 protein expressions in rat spinal cord, ACC and VPL tissues of the model group were significantly increased versus the normal group (all P<0.01); the P2X3 protein expressions in rat spinal cord, ACC and VPL tissues of the mild moxibustion group and the P2X3 receptor antagonist group were significantly reduced versus the model group (all P<0.01). Conclusion: Mild moxibustion can inhibit the P2X3 receptor expressions in the spinal cord, ACC, and VPL tissues of IBS visceral hyperalgesia model rats, which may be the mechanism of mild moxibustion in relieving the central sensitization of rats with IBS visceral hyperalgesia.

Effect of Da Jianzhongtang on Visceral Pain in Rats with Irritable Bowel Syndrome / 中国实验方剂学杂志

Objective:To investigate the effects of Da Jianzhongtang on substance P （SP）， mast cells （MC）， Toll like receptor 2 （TLR2）， TLR4 on MC model and nuclear transcription factor （NF）-<italic>κ</italic>B p65 in visceral pain rats with irritable bowel syndrome （IBS）， and explore its mechanism of action on IBS visceral pain. Method:Forty-eight 3-day-old SD rats were randomly divided into 6 groups： the control group （control）， irritable bowel syndrome group （IBS）， ketotifen group （Ketotifen，0.18 mg·kg^-1）， Da Jianzhongtang low， medium and high dose groups （DJZT-L， DJZT-M， DJZT-H，2.16，1.08，0.54 g·kg^-1）， with 8 rats in each group. Intragastric administration lasted for 2 weeks. Maternal separation method was used to establish the IBS visceral pain model in rats. The visceral sensitivity of rats was evaluated at 60， 40 and 20 mmHg （1 mmHg≈0.133 kPa） with Abdominal wall withdrawal response （AWR） scale. SP and NF-<italic>κ</italic>B p65 protein expression levels in colon tissue were detected with Western blotting technique. TLR2 and TLR4 proteins on mast cell membrane were detected by immunofluorescence staining. The degranulation rate of mast cells in colon tissue was detected by toluidine blue staining. Result:Compared with normal rats， AWR scores of model rats significantly increased at 60， 40， and 20 mmHg pressure （<italic>P</italic><0.05，<italic>P</italic><0.01）， the degranulation rate of mast cells in colon tissue and SP protein expression in colon tissue significantly increased （<italic>P</italic><0.01）， TLR2， TLR4， and nuclear NF-<italic>κ</italic>B p65 expression on mast cell membrane significantly increased （<italic>P</italic><0.01）. Compared with model rats， the AWR scores of DJZT-H group （pressure of 40， 20 mmHg） and DJZT-M group （pressure of 60， 40， 20 mmHg） significantly decreased. Meanwhile， the degranulation rate of colon mast cells， and the SP， TLR2， TLR4， and NF-<italic>κ</italic>B p65 expression also significantly decreased （<italic>P</italic><0.05，<italic>P</italic><0.01）. Conclusion:Da Jianzhongtang can affect mast cell activity and finally decrease visceral pain of IBS rats by down-regulating SP in colon tissue.

Study on the Improvement Effects of Dajianzhong Decoction on Irritable Bowel Syndrome Visceral Pain Model Rats Based on EGC / 中国药房

OBJECTIVE：To study th e improvement effect and mechanism of Dajianzhong decoction on irritable bowel syndrome（IBS）visceral pain model rats. METHODS ：Totally 48 male non-weaning rats were randomly divided into normal control group ，model group ，pinaverium bromide group （positive control ，45 mg/kg）and Dajianzhong decoction high-dose ， medium-dose and low-dose groups （2.16，1.08，0.54 g/kg，by crude drug ），with 8 rats in each group. Except for normal control group，IBS visceral pain model was established by mother and child separation ，acetic acid enema ，ovalbumin intraperitoneal Remote limb precondition - ing protects against ischemia induced neuronal death through ameliorating neuronal oxidative DNA damage injection in other groups for 57 d. On the 58th day ，the rats in administration groups were given the corresponding drugs intragastrically，and model group and normal control group were given constant volume of purified water ，once a day ，for consecutive 14 d. The general condition of rats was observed ；abdominal wall withdrawal reaction （AWR）was adopted to evaluate the visceral sensitivity of rats in each group under 20，40，60，and 80 mmHg （1 mmHg＝0.133 kPa）pressure；HE staining method was used to observe the colon pathological features of rats in each group. Western blotting assay was used to detect the protein expression of intestinal glial cells markers fibrillary acidic protein （GFAP），nerve growth factor （NGF）and its receptor TrkA in colon tissue. RESULTS ：The mucosal layer of colon tissue in rats of model group was discontinuous ，gland edema was observed and lymphocytes ，neutrophils and eosinophils were scattered in the lamina propria. In Dajianzhong decoction low-does group，the mucosal layer of colon tissue was incomplete ，some glands were slightly edematous ，and a few lymphocytes ， neutrophils in the lamina propria. The colonic mucosa epithelial structure was intact ，glands arranged regularly ，and no degenerative necrosis and inflammatory cells were observed in Dajianzhong decoction medium- and high-dose groups and pinaverium bromide group. Compared with normal control group ，AWR scores under 20，40，and 60 mmHg pressure ，relative protein expression of GFAR ，NGF and TrkA were all increased significantly in model group and Dajianzhong decoction low-does groups（P＜0.05 or P＜0.01）. Compared with model group ，AWR scores under 20，and 40 mmHg pressure in Dajianzhong decoction medium- and high-dose groups and pinaverium bromide group ，AWR scores under 60 mmHg pressure in Dajianzhong decoction high-dose group and pinaverium bromide group ，relative protein expression of GFAP ，NGF，TrkA in colon tissue in Dajianzhong decoction medium- and high-dose groups and pinaverium bromide group were all decreased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS ：Dajianzhong decoction could improve the visceral pain of IBS model rats by inhibiting the activation of intestinal glial cells and reducing the expression of NGF and TrkA.

Spinal Cord Electrical Stimulation for Refractory Angina Treatment

Cardiovascular disease (CVD) is the main cause of death worldwide, including in Brazil. Angina pectoris is a challenging disease because its clinical manifestation is not always related to the degree of obstruction. Visceral pain fromany source can be totally disabling. It influences all aspects of the life of a patient and it can be one of the main causes of absence from work and of family disruption. Spinal cord electrical stimulation (SCES) has been traditionally applied for the treatment of neuropathic pain, with good to excellent results. Visceral pain syndrome can be as debilitating and disabling as somatic or neuropathic pain; however, there seems to be a lack of consensus on the appropriate treatment and strategies for these disorders. Themajor difference of SCES for visceral pain, compared to postlaminectomy syndrome or to regional complex syndrome, is the number of stimulated dermatomes. In most viscera, the somatotopic arrangement has two to four medullar levels, sometimes requiring laterality. After reviewing the literature, we have concluded that SCES is now a viable, low-risk option with satisfactory results for the treatment of neuropathic and visceral pain; therefore, it can be used in refractory angina after the failure of standard therapy. However, further studies are required to increase the application and efficacy of this procedure in the clinical practice.

Estrogen modulation of visceral pain / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.

Neonatal Maternal Deprivation Followed by Adult Stress Enhances Adrenergic Signaling to Advance Visceral Hypersensitivity / 神经科学通报·英文版

The pathophysiology of visceral pain in patients with irritable bowel syndrome remains largely unknown. Our previous study showed that neonatal maternal deprivation (NMD) does not induce visceral hypersensitivity at the age of 6 weeks in rats. The aim of this study was to determine whether NMD followed by adult stress at the age of 6 weeks induces visceral pain in rats and to investigate the roles of adrenergic signaling in visceral pain. Here we showed that NMD rats exhibited visceral hypersensitivity 6 h and 24 h after the termination of adult multiple stressors (AMSs). The plasma level of norepinephrine was significantly increased in NMD rats after AMSs. Whole-cell patch-clamp recording showed that the excitability of dorsal root ganglion (DRG) neurons from NMD rats with AMSs was remarkably increased. The expression of β adrenergic receptors at the protein and mRNA levels was markedly higher in NMD rats with AMSs than in rats with NMD alone. Inhibition of β adrenergic receptors with propranolol or butoxamine enhanced the colorectal distention threshold and application of butoxamine also reversed the enhanced hypersensitivity of DRG neurons. Overall, our data demonstrate that AMS induces visceral hypersensitivity in NMD rats, in part due to enhanced NE-β adrenergic signaling in DRGs.

Vagal Transient Receptor Potential Ankyrin 1 Mediates Stress-exacerbated Visceral Mechanonociception After Antral Cold Exposure

BACKGROUND/AIMS: Abdominal pain can be evoked or exacerbated after gastrointestinal cold stimulation in some patients with diarrhea-predominant irritable bowel syndrome (IBS-D), indicating a low temperature-induced sensitization of visceral perception. We investigated the role of vagal transient receptor potential ankyrin 1 (TRPA1, a cold-sensing ion channel) in cold-aggravated visceral mechanonociception in a stress-induced IBS animal model. METHODS: TRPA1 expression was examined in antral biopsies of healthy controls and IBS-D patients. Abdominal symptoms were assessed before and after warm or cold water intake. The visceromotor response (VMR) to colorectal distention (CRD) following intra-antral infusion of cold saline was measured in animals undergoing sham or chronic water avoidance stress. TRPA1 expression, extracellular signal-regulated protein kinase 1/2 (ERK1/2) phosphorylation, and neuronal calcium influx in vagal afferents were assessed. RESULTS: Compared to healthy controls, IBS-D patients displayed elevated antral TRPA1 expression, which was associated with symptom scores after cold (4°C) water intake. Intra-antral infusion of cold saline increased VMR to CRD in naive rats, an effect dependent on vagal afferents. In stressed rats, this effect was greatly enhanced. Functional blockade and gene deletion of TRPA1 abolished the cold effect on visceral nociception. TRPA1 expression in vagal (but not spinal) afferents increased after stress. Moreover, the cold-induced, TRPA1-dependent ERK1/2 activation and calcium influx in nodose neurons were more robust in stressed rats. CONCLUSIONS: Stress-exaggerated visceral mechanonociception after antral cold exposure may involve up-regulation of TRPA1 expression and function on vagal afferents. Our findings reveal a novel mechanism for abnormal gastrointestinal cold sensing in IBS.

Decreased miR-325-5p Contributes to Visceral Hypersensitivity Through Post-transcriptional Upregulation of CCL2 in Rat Dorsal Root Ganglia / 神经科学通报·英文版

Chronic visceral hypersensitivity is an important type of chronic pain with unknown etiology and pathophysiology. Recent studies have shown that epigenetic regulation plays an important role in the development of chronic pain conditions. However, the role of miRNA-325-5p in chronic visceral pain remains unknown. The present study was designed to determine the roles and mechanism of miRNA-325-5p in a rat model of chronic visceral pain. This model was induced by neonatal colonic inflammation (NCI). In adulthood, NCI led to a significant reduction in the expression of miRNA-325-5p in colon-related dorsal root ganglia (DRGs), starting to decrease at the age of 4 weeks and being maintained to 8 weeks. Intrathecal administration of miRNA-325-5p agomir significantly enhanced the colorectal distention (CRD) threshold in a time-dependent manner. NCI also markedly increased the expression of CCL2 (C-C motif chemokine ligand 2) in colon-related DRGs at the mRNA and protein levels relative to age-matched control rats. The expression of CXCL12, IL33, SFRS7, and LGI1 was not significantly altered in NCI rats. CCL2 was co-expressed in NeuN-positive DRG neurons but not in glutamine synthetase-positive glial cells. Furthermore, CCL2 was mainly expressed in isolectin B4-binding- and calcitonin gene-related peptide-positive DRG neurons but in few NF-200-positive cells. More importantly, CCL2 was expressed in miR-325-5p-positive DRG neurons. Intrathecal injection of miRNA-325-5p agomir remarkably reduced the upregulation of CCL2 in NCI rats. Administration of Bindarit, an inhibitor of CCL2, markedly raised the CRD threshold in NCI rats in a dose- and time-dependent manner. These data suggest that NCI suppresses miRNA-325-5p expression and enhances CCL2 expression, thus contributing to visceral hypersensitivity in adult rats.

Mechanism of dexmedetomidine-induced reduction of acute visceral pain in rats: relationship be-tween α2 adrenergic receptors and expression of Nav1. 8 in dorsal root ganglion neurons / 中华麻醉学杂志

Objective To evaluate the relationship betweenα2 adrenergic receptors and expression of Nav1. 8 in dorsal root ganglion (DRG) neurons, and to illuminate the mechanism of dexmedetomidine-induced reduction of acute visceral pain in rats. Methods Thirty-two clean-grade healthy adult male Spra-gue-Dawley rats, aged 6-8 weeks, weighing 180-220 g, were divided into 4 groups ( n=8 each) using a random number table method: control group ( group C ) , acute visceral pain group ( group VP ) , dexmedetomidine group (group D), and dexmedetomidine plus atipamezole group (group DA). In VP, D and DA groups, 10-3 mmol∕L capsaicin 1. 3 ml was injected into the rectum at a dose of 10-3 mmol∕L to establish the acute visceral pain model, while the equal volume of normal saline was given instead in group C. Atipamezole 1 mg∕kg was subcutaneously injected through the back of the neck at 20 min before establishing the model in group DA. Dexmedetomidine 10μg∕kg was injected through the tail vein at 15 min before establishing the model in D and DA groups, while the equal volume of normal saline was given instead at the correspording time points in C and VP groups. The visceral pain behavior score was recorded at 1 h after establishing the model. The animals were then sacrificed, and DRGs of the lumbar segment (L3-6) were removed for determination of the number of Nav1. 8 positive DRG neurons (by immunohisto-chemistry) and expression of Nav1. 8 mRNA (by quantitative real-time polymerase chain reaction). Results Compared with group C, the visceral behavior scores and the number of Nav 1. 8 positive DRG neurons were significantly increased, and the expression of Nav 1. 8 mRNA was up-regulated in VP, D and DA groups (P<0. 05). Compared with group VP, the visceral behavior score and the number of Nav1. 8 positive DRG neurons were significantly decreased, and the expression of Nav 1. 8 mRNA was down-regulated in D and DA groups (P<0. 05). Compared with group D, the visceral behavior scores and the number of Nav1. 8 positive DRG neurons were significantly increased, and the expression of Nav1. 8 mRNA was up-regulated in group DA ( P<0. 05) . Conclusion The mechanism by which dexmedetomidine reduces acute visceral pain is related to activatingα2 adrenergic receptors and to down-regulating the expression of Nav1. 8 in DRG neu-rons of rats.

Bifidobacterium longum and Lactobacillus helveticus Synergistically Suppress Stress-related Visceral Hypersensitivity Through Hypothalamic-Pituitary-Adrenal Axis Modulation

BACKGROUND/AIMS: Visceral pain and hypothalamic-pituitary-adrenal axis (HPA) dysregulation is a common characteristic in irritable bowel syndrome (IBS) patients. Previously, we reported that a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) prevents chronic stress-mediated brain function abnormalities by attenuating the HPA axis response. Here, we compared the effect between different probiotic treatments on the perception of visceral pain during colorectal distension (CRD) following a chronic stress and the consequences to the activity of the HPA axis. METHODS: After a 2-week treatment with a combined probiotic formulation, or L. helveticus or B. longum alone in stressed mice, the visceral pain in response to CRD was recorded. The expression of glucocorticoid receptors was determined in the different brain areas involved in the stress response (hypothalamus, hippocampus, and prefrontal cortex). The plasma levels of stress hormones were also measured. RESULTS: A pretreatment using the combination of probiotic formulation significantly reduces the chronic stress-induced visceral hypersensitivity respectively at 0.06, 0.08, and 0.10 mL CRD volume. However, a single probiotic (B. longum or L. helveticus) administration is less effective in reducing visceral pain in stressed mice. Moreover, the expression of the glucocorticoid receptor mRNA was consistently up-regulated in several brain areas after pretreatment with a combined probiotic, which correlated with the normalization of stress response compared to the inconsistent effects of a single probiotic. CONCLUSION: The combination of L. helveticus and B. longum is more effective in regulating glucocorticoid negative feedback on the HPA axis than probiotic alone and subsequently in treating stress-induced visceral pain.

Electroacupuncture of "Tianshu" (ST 25) Suppresses Visceral Pain Possibly by Down-regulating Mast Cell Activation, and Tryptase and SP Expression in Rats with Post-infectious Irritable Bowel Syndrome / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Tianshu" (ST 25) on visceral pain and colonic mast cell (MCs) number and tryptase and SP expression in post-infectious irritable bowel syndrome (PI-IBS) rats, so as to reveal its mechanisms underlying improvement of PI-IBS. METHODS: Forty-five female Wistar rats were randomly divided into control, model and EA groups (15 rats/ group, 3 rats/group used for H. E. staining, and 12 rats/group for immunohistochemistry). The PI-IBS model was established by intra-anal injection of mixed liquor of 50% ethyl alcohol and trinitro-benzene-sulfonic acid (TNBS). EA (2 Hz/15 Hz, 0.5-1.0 mA) was applied to bilateral "Tianshu" (ST 25) for 30 min, once every day for 14 days. The visceral pain was measured by abdominal withdrawal reflex (AWR), for which the rectal implanted air balloon was dilated by infusion of normal saline. The histopathological changes of the colon tissue were observed after H. E. staining, and the colonic MCs were displayed by Toluidine blue staining. The expression of tryptase and SP proteins in the colon specimens were detected by immunohistochemistry. RESULTS: The AWR threshold was significantly lowered in the model group relevant to the control group (P<0.05) and considerably increased after EA intervention in comparison with the model group (P<0.05). The number of MCs and the expression levels of colonic tryptase and SP proteins in the colon tissues were significantly higher in the model group than in the control group (P<0.05), and obviously lower after EA intervention in the EA group than in the model group (P<0.05). CONCLUSION: EA of "Tianshu" (ST 25) can inhibit visceral pain in PI-IBS rats, which may be associated with its effects in activating MCs and down-regulating the expression of tryptase and SP proteins in the colonic tissues.

Electroacupuncture Relieves Visceral Hypersensitivity by Down-regulating Mast Cell Number，PAR-2/TRPV 1 Signaling, etc. in Colonic Tissue of Rats with Irritable Bowel Syndrome / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of "Shangjuxu" (ST 37, Lower Confluent point) and "Tianshu" (ST 25, Front-Mu point) on visceral pain and expression of colonic tryptase(Try), proteinase-activated receptor 2(PAR-2)，transient receptor potential channel vanilloid subfamily member 1 (TPRV 1)，substance P (SP) and calcitonin gene-related peptide (CGRP) in rats with irritable bowel syndrome (IBS), so as to explore its mechanisms underlying improvement of IBS. METHODS: Forty male Sprague Dawley rats were equally randomized into normal control (control), model, medication and EA groups (n＝10 in each). The IBS model was established by chronic acute combining stress (CACS, water deprivation, fasting, tail clamping, forced swimming in ice water, restraint, etc.) for 21 days. Rats of the medication group were treated by gavage of Pinaverium Bromide (1 mg/mL, 15 mg/kg), once daily for 14 d. EA (10 Hz/50 Hz, 0.2－0.3 mA) was applied to bilateral ST 37 and ST 25 for 30 min, once daily for 14 d. The muscular withdrawal reflex (AWR) of both abdomen and buttock was detected by colorectal distension (CRD) with a water-filled balloon for examining the visceral hypersensitivity. The number of mast cells in the colonic tissue was counted after toluidine blue stain. The immunoactivity of colonic Try was determined by immunochemistry and the expression of colonic PAR-2, TRVP 1, SP and CGRP proteins detected by Western blot. RESULTS: After modeling, the body weight was significantly decreased in IBS rats of the model, medication and EA groups compared with their own individual pre-treatment and with the control group (P0.05)．. CONCLUSION: EA of ST 37 and ST 25 can relieve visceral hypersensitivity in IBS rats, which may be associated with its effects in down-regulating the number of MC and the expression of PAR-2, TRVP 1, SP, CGRP and Try proteins in the colonic tissue.

Effect of moxibustion on CRF and CRFR1 expressions in hypothalamus of TNBS-induced experimental colitis rats / 针灸推拿医学（英文版）

Objective:To observe the effect of moxibustion on the protein and mRNA expressions of corticotropin-releasing factor (CRF)and corticotropin-releasing factor receptor 1 (CRFR1) in hypothalamus of trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis rats,and to explore the central mechanisms of moxibustion in improving visceral pain and the pain-related emotions in experimental colitis rats.Methods:Thirty-six Sprague-Dawley (SD) rats were randomly divided into a normal group (NG),a model group (MG),a herb-partitioned moxibustion group (HPMG) and a sham herb-partitioned moxibustion group (SHPMG).Except the NG,rats in the remaining three groups all received TNBS enema to establish experimental colitis models.The HPMG received herb-partitioned moxibustion (HPM) at bilateral Tianshu (ST 25) and Qihai (CV 6) for intervention;for the SHPMG,the herbal cakes and moxa cones were only placed on the acupoints but not ignited;rats in the MG and NG were only fixed in the same way as those in the HPMG but did not receive any treatment.At the end of the intervention,the abdominal withdrawal reflex (AWR) score,the open field test (OFT) score and the elevated plus maze (EPM) score were observed to measure the changes in visceral pain and pain-related emotions of the rats.The enzyme-linked immunosorbent assay (ELISA) was used to examine the expressions of CRF and CRFR1 proteins in hypothalamus;the fluorescence-based quantitative polymerase chain reaction (PCR) was used to detect the expressions of CRF and CRFR1 mRNAs in hypothalamus.Results:Compared with the NG,the AWR score increased significantly and the OFT and EPM scores dropped significantly in the MG (all P＜0.05),and the expressions of hypothalamic CRF and CRFR1 proteins and mRNAs increased significantly (all P＜0.01).Compared with the MG and SHPMG,the AWR score dropped significantly and the OFT and EPM scores increased significantly in the HPMG (all P＜0.01),and the expressions of hypothalamic CRF and CRFR1 proteins and mRNAs decreased significantly (all P＜0.05).There were no significant differences between the MG and the SHPMG (all P＞0.05).Conclusion:HPM can down-regulate the abnormally increased expressions of CRF and CRFR1 proteins and mRNAs in hypothalamus of the TNBS-induced experimental colitis rats,which is plausibly one of its action mechanisms in mitigating visceral pain and the pain-related emotions in the experimental colitis rats.

Effect of dexmedetomidine pretreatment on inflammatory visceral pain in rats / 中华麻醉学杂志

Objective To investigate the effect of dexmedetomidine pretreatment on inflammatory visceral pain in rats. Methods Forty healthy male Wistar rats, weighing 200-300 g, aged 6-8 weeks, were divided into 5 groups ( n=8 each) using a random number table method: control group ( group C) , visceral pain group ( group VP ) , dexmedetomidine 1 μg∕kg group ( group Dex1 ) , dexmedetomidine 5μg∕kg group ( group Dex2) and dexmedetomidine 10μg∕kg group ( group Dex3) . The model of inflammato-ry visceral pain was established by intraperitoneally injecting 0. 9％ acetic acid 10 ml∕kg in VP, Dex1, Dex2 and Dex3 groups, and the equal volume of normal saline was given instead in group C. At 15 min be-fore intraperitoneal injection, dexmedetomidine 1, 5 and 10μg∕kg were injected via the tail vein in Dex1, Dex2 and Dex3 groups, respectively, and the equal volume of normal saline was given instead in C and VP groups. Behavioral changes of rats were observed within 60 min after the model was established, and viscer-al pain index ( VPI) was calculated. Blood samples were collected from the hearts at 180 min after establis-hing the model for determination of tumor necrosis factor-alpha ( TNF-α) concentrations in serum. The ani-mals were then sacrificed, and colons were obtained for examination of pathological changes with a light mi-croscope. Results Compared with group C, the VPI and serum TNF-α concentrations were significantly increased in VP and Dex1-2 groups, and the serum TNF-αconcentrations were significantly increased ( P<0. 05), and no significant change was found in VPI in group Dex3 (P>0. 05). Compared with group VP, the VPI and serum TNF-α concentrations were significantly decreased (P<0. 05), and the pathological changes of colon tissues were significantly attenuated in group Dex1-3. Compared with group Dex1, the VPI and serum TNF-α concentrations were significantly decreased ( P<0. 01) , and the pathological changes of colon tissues were significantly attenuated in Dex2-3 groups. Compared with group Dex2, the VPI and ser-um TNF-α concentrations were significantly decreased (P<0. 01), and the pathological changes of colon tissues were significantly attenuated in group Dex3. Conclusion Dexmedetomidine pretreatment can miti-gate inflammatory visceral pain in rats.

Clinical evidence on visceral pain. Systematic review / Evidência clínica sobre dor visceral. Revisão sistemática

ABSTRACT BACKGROUND AND OBJECTIVES: Visceral pain is induced by abnormalities of organs such as stomach, kidneys, bladder, gallbladder, intestines and others and includes distension, ischemia, inflammation and mesenteric traction. It is responsible for physical and psychic incapacity, absenteeism and poor quality of life. This study aimed at discussing major aspects of visceral pain with regard to prevalence, etiology and diagnosis. CONTENTS: According to Evidence-Based Medicine concepts, visceral pain etiology, diagnosis and prognosis were reviewed in LILACS, EMBASE and Pubmed databases. Therapeutic studies were not selected. The following terms were used as search strategy: ("visceral pain"[MeSH Terms] OR ("visceral"[All Fields] AND "pain"[All Fields]) OR "visceral pain"[All Fields]). Only studies published in Portuguese, English or Spanish were included. Narrative reviews with opinionated content and specific therapeutic procedures of medical specialties were excluded. Studies on visceral pain related to heart, cancer and musculoskeletal diseases and pregnancy were also excluded. CONCLUSION: Visceral pain is a heterogeneous condition where most frequent presentation is abdominal pain in the course of irritable bowel syndrome. Other diseases induce visceral pain and adequate diagnosis is critical for effective treatment.

RESUMO JUSTIFICATIVA E OBJETIVOS: A dor visceral é causada por anormalidades de órgãos como o estômago, rim, bexiga, vesícula biliar, intestinos ou outros e inclui distensão, isquemia, inflamação e tração do mesentério. É responsável por incapacidade física e psíquica, absenteísmo do trabalho e má qualidade de vida. O objetivo deste estudo foi discutir os principais aspectos da dor visceral relacionados a prevalência, etiologia e diagnóstico. CONTEÚDO: Foram revisados segundo os preceitos da Medicina Baseada em Evidência os enfoques etiológicos, diagnóstico e prognóstico da dor visceral nas bases de indexações biomédicas, LILACS, EMBASE e Pubmed. Não foram selecionados os estudos terapêuticos. Utilizou-se como estratégia de busca os termos: ("visceral pain"[MeSH Terms] OR ("visceral"[All Fields] AND "pain"[All Fields]) OR "visceral pain"[All Fields]). Somente foram incluídos os estudos publicados em português, inglês ou espanhol. Foram excluídas as revisões narrativas de conteúdo opinativo e procedimentos terapêuticos específicos das especialidades médicas. Também foram excluídos os estudos sobre dor visceral relacionada às doenças do coração, neoplásicas, musculoesqueléticas e a gestação. CONCLUSÃO: A dor visceral é uma condição heterogênea, cuja apresentação mais frequente é de dor abdominal no curso de síndrome do intestino irritável. Outras doenças cursam com dor visceral e o diagnóstico adequado é fundamental para o tratamento eficaz.

Effects of intraperitoneal injection of 5-HT2A receptor antagonist MDL11939 on acute and chronic pain in mice / 中国药理学通报

Aim To investigate the effects and signifi-cance of 5-HT2A receptor antagonist MDL1 1 939 on a-mice.Methods Kunming male mice were suffered a-cute acetic acid visceral pain,acute incision pain and CCI neuropathic pain.After each animal model was es-tablished,MDL1 1 939 was injected intraperitoneally. The writhing reaction was used to assess acute acetic acid visceral pain,while the thermal withdrawal laten-cy (TWL)was used to evaluate the acute incision pain and CCI neuropathic pain.Results Compared with the control group,MDL1 1 939 (0.25,0.5,1 .0 mg· kg -1 ,i.p.)relieved acetic acid visceral pain signifi-cantly in a dose-dependent manner in mice,as re-vealed by the significant reduction of the number of twisting.In acute incision pain and CCI neuropathic pain,MDL1 1 939 (0.5 mg·kg -1 ,i.p.)significantly increased TWL level.Conclusion 5-HT2A receptor antagonist MDL1 1 939 has analgesic effects on visceral pain,acute pain and neuropathic pain,which might be a novel therapeutic target to treat different pain in clini-cal situations.