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

Research Progress of Central and Peripheral Corticotropin-Releasing Hormone in Irritable Bowel Syndrome with Comorbid Dysthymic Disorders

Irritable bowel syndrome (IBS) is considered a stress disorder characterized by psychological and gastrointestinal dysfunction. IBS patients not only suffer from intestinal symptoms such as abdominal pain, diarrhea, or constipation but also, experience dysthymic disorders such as anxiety and depression. Studies have found that corticotropin-releasing hormone plays a key role in IBS with comorbid dysthymic disorders. Next, we will summarize the effects of corticotropin-releasing hormone from the central nervous system and periphery on IBS with comorbid dysthymic disorders and relevant treatments based on published literatures in recent years.

Modulation of visceral pain by brain nuclei and brain circuits and the role of acupuncture: a narrative review

Visceral pain is a complex and heterogeneous pain condition that is often associated with pain-related negative emotional states, including anxiety and depression, and can exert serious effects on a patient's physical and mental health. According to modeling stimulation protocols, the current animal models of visceral pain mainly include the mechanical dilatation model, the ischemic model, and the inflammatory model. Acupuncture can exert analgesic effects by integrating and interacting input signals from acupuncture points and the sites of pain in the central nervous system. The brain nuclei involved in regulating visceral pain mainly include the nucleus of the solitary tract, parabrachial nucleus (PBN), locus coeruleus (LC), rostral ventromedial medulla (RVM), anterior cingulate cortex (ACC), paraventricular nucleus (PVN), and the amygdala. The neural circuits involved are PBN-amygdala, LC-RVM, amygdala-insula, ACC-amygdala, claustrum-ACC, bed nucleus of the stria terminalis-PVN and the PVN-ventral lateral septum circuit. Signals generated by acupuncture can modulate the central structures and interconnected neural circuits of multiple brain regions, including the medulla oblongata, cerebral cortex, thalamus, and hypothalamus. This analgesic process also involves the participation of various neurotransmitters and/or receptors, such as 5-hydroxytryptamine, glutamate, and enkephalin. In addition, acupuncture can regulate visceral pain by influencing functional connections between different brain regions and regulating glucose metabolism. However, there are still some limitations in the research efforts focusing on the specific brain mechanisms associated with the effects of acupuncture on the alleviation of visceral pain. Further animal experiments and clinical studies are now needed to improve our understanding of this area.

The efficacy and neural mechanism of acupuncture therapy in the treatment of visceral hypersensitivity in irritable bowel syndrome

Irritable Bowel Syndrome (IBS) is a complex functional gastrointestinal disorder primarily characterized by chronic abdominal pain, bloating, and altered bowel habits. Chronic abdominal pain caused by visceral Hypersensitivity (VH) is the main reason why patients with IBS seek medication. Significant research effort has been devoted to the efficacy of acupuncture as a non-drug alternative therapy for visceral-hyperalgesia-induced IBS. Herein, we examined the central and peripheral analgesic mechanisms of acupuncture in IBS treatment. Acupuncture can improve inflammation and relieve pain by reducing 5-hydroxytryptamine and 5-HT3A receptor expression and increasing 5-HT4 receptor expression in peripheral intestinal sensory endings. Moreover, acupuncture can also activate the transient receptor potential vanillin 1 channel, block the activity of intestinal glial cells, and reduce the secretion of local pain-related neurotransmitters, thereby weakening peripheral sensitization. Moreover, by inhibiting the activation of N-methyl-D-aspartate receptor ion channels in the dorsal horn of the spinal cord and anterior cingulate cortex or releasing opioids, acupuncture can block excessive stimulation of abnormal pain signals in the brain and spinal cord. It can also stimulate glial cells (through the P2X7 and prokinetic protein pathways) to block VH pain perception and cognition. Furthermore, acupuncture can regulate the emotional components of IBS by targeting hypothalamic-pituitary-adrenal axis-related hormones and neurotransmitters via relevant brain nuclei, hence improving the IBS-induced VH response. These findings provide a scientific basis for acupuncture as an effective clinical adjuvant therapy for IBS pain.

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.

High-frequency electroacupuncture improves endometrial receptivity via regulating cell adhesion molecules and leukemia inhibitory factor / signal transducer and activator of transcription signaling pathway

Controlled ovarian hyperstimulation (COH) impairs the endometrium receptivity during the implantation window, resulting in a lower clinical pregnancy rate and a higher abortion rate. Our study explored the effect of electroacupuncture on the endometrial receptivity of COH rats. Female rats were randomly divided into normal treatment (Normal), model treatment (Model), low-frequency electroacupuncture treatment (LF-EA) and high-frequency electroacupuncture treatment (HF-EA). Rats in the Model, LF-EA, and HF-EA treatment groups were injected with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) to establish a model of COH rats. Compared with the Normal, the endometrial thickness, the number of pinopodes and amount of blastocyst implantation in the Model group were significantly reduced. Among them, the endometrial thickness and the amount of blastocyst implantation in the Model group were substantially decreased than those in the HF-EA group. High-frequency electroacupuncture treatment could markedly reduce the protein expression levels of E-cadherin, β-catenin and claudin-1 (CLDN1). During HF-EA treatment, the LIF/STAT3 signaling pathway of COH rats was enhanced. In conclusion, electroacupuncture could improve the endometrium receptivity and promote the blastocyst implantation in COH rats by reducing cell adhesion molecules and enhancing the LIF/STAT3 signaling pathway.Highlights High-frequency electroacupuncture could effectively improve endometrial receptivity and blastocyst implantation amount in COH rats.Electroacupuncture, especially high-frequency electroacupuncture, could significantly increase endometrial thickness and the number of pinopodes.High-frequency electroacupuncture significantly reduced the protein expression levels of E-cadherin, β-catenin and CLDN1 adhesion molecules in COH rats.High-frequency electroacupuncture could markedly enhance the LIF/STAT3 signaling pathway in COH rats.

Does Use of Acupuncture Reduce the Risk of Type 2 Diabetes Mellitus in Patients With Rheumatoid Arthritis? Evidence From a Universal Coverage Health Care System

Objectives: Although acupuncture is often advocated for patients with rheumatoid arthritis (RA), its efficacy for type 2 diabetes mellitus (T2DM), a common metabolic disease among RA cohorts, has not yet been established. This retrospective cohort study aimed to determine the association between acupuncture use and the development of T2DM among them.

Methods: Data were collected from 1999 through 2008 for individuals aged 20–70 years in the nationwide insurance database of Taiwan. From them, we extracted 4,941 subjects within newly diagnosed RA and being T2DM free at baseline. A total of 2,237 patients had ever received acupuncture, and 2,704 patients without receiving acupuncture were designated as a control group. All of them were followed to the end of 2013 to identify T2DM incidence. The Cox proportional hazards regression model was utilized to obtain the adjusted hazard ratio (HR) for acupuncture use.

Results: Compared with the RA subjects without use of acupuncture, the incidence of T2DM was lower for those who received acupuncture, with the incidence rates of 24.50 and 18.00 per 1,000 person-years (PYs), respectively. After adjusting for potential confounders, use of acupuncture was significantly related to the lower T2DM risk, with the adjusted HR of 0.73 [95% confidence interval (CI) 0.65–0.86]. Those who used acupuncture for more than five sessions had the greatest benefit in lowering the susceptibility to T2DM.

Conclusion: Adding acupuncture into conventional treatment for RA was found to be related to lower risk of T2DM among RA patients. Further clinical and mechanistic studies are warranted.

Neuroimmune connections between corticotropin-releasing hormone and mast cells: novel strategies for the treatment of neurodegenerative diseases

Corticotropin-releasing hormone is a critical component of the hypothalamic–pituitary–adrenal axis, which plays a major role in the body’s immune response to stress. Mast cells are both sensors and effectors in the interaction between the nervous and immune systems. As first responders to stress, mast cells can initiate, amplify and prolong neuroimmune responses upon activation. Corticotropin-releasing hormone plays a pivotal role in triggering stress responses and related diseases by acting on its receptors in mast cells. Corticotropin-releasing hormone can stimulate mast cell activation, influence the activation of immune cells by peripheral nerves and modulate neuroimmune interactions. The latest evidence shows that the release of corticotropin-releasing hormone induces the degranulation of mast cells under stress conditions, leading to disruption of the blood-brain barrier, which plays an important role in neurological diseases, such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, autism spectrum disorder and amyotrophic lateral sclerosis. Recent studies suggest that stress increases intestinal permeability and disrupts the blood-brain barrier through corticotropin-releasing hormone-mediated activation of mast cells, providing new insight into the complex interplay between the brain and gastrointestinal tract. The neuroimmune target of mast cells is the site at which the corticotropin-releasing hormone directly participates in the inflammatory responses of nerve terminals. In this review, we focus on the neuroimmune connections between corticotropin-releasing hormone and mast cells, with the aim of providing novel potential therapeutic targets for inflammatory, autoimmune and nervous system diseases.

Intra- and inter-evaluator reliability of the MyotonPRO for the assessment of the viscoelastic properties of caesarean section scar and unscarred skin

BACKGROUND

The clinical evaluation of viscoelastic properties of the Caesarean section (C-section) scar, such as stiffness and elasticity, is usually carried out using subjective scales and palpation techniques. There is currently no reliable and valid tool that objectively quantifies these properties. The MyotonPRO could fill this gap.

MATERIALS AND METHODS

Nineteen healthy women aged between 21 and 40 years with C-section scars participated in this reliability study. Two points, one on the scar and one on unscarred skin, were measured four times successively with the MyotonPRO by three independent evaluators on the same day. The intra-class correlation (ICC) coefficients were estimated using a two-factor ANOVA to determine the inter- and intra-rater reliability. The capacity of the MyotonPRO to discriminate the viscoelastic properties of the C-Section scar against unscarred skin was assessed using the Wilcoxon signed rank test.

RESULTS

The intra- and inter-rater reliability of the viscoelastic property measurements was good to excellent (ICC 0.99-1.00 and 0.87-0.98, respectively). There was no significant difference between C-section scar and unscarred skin in terms of elasticity (P = .737). Significant differences between C-section scars and unscarred skin tissue were observed for tone (P < .001), stiffness (P < .001), creep (P < .001), and mechanical stress relaxation time (P < .001).

CONCLUSION

The MyotonPRO is a reliable tool for an objective measurement of the viscoelastic properties of the C-section scar and unscarred skin. The MyotonPRO can discriminate the viscoelastic properties of the C-section scar against the unscarred skin, for tone, stiffness, creep and relaxation times, but not for elasticity.

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.

Acupuncture for refractory gastro-oesophageal reflux disease: a systematic review and meta-analysis protocol

INTRODUCTION

Refractory gastro-oesophageal reflux disease (rGORD) is a common disease, affecting patients' quality of life. Since conventional medicines have limitations, like low effective rates and adverse events, acupuncture may be a promising therapy for rGORD. While no related systematic review has been published, the present study is designed to evaluate the efficacy and safety of acupuncture for rGORD.

METHODS AND ANALYSIS

PubMed, the Cochrane Central Register of Controlled Trials and Chinese electronic databases, including China National Knowledge Infrastructure, Wan Fang database, VIP, SinoMed and the Chinese Clinical Trial Registry, will be searched from establishment of the database to 31 August 2019. There will be no limitations on language, and all articles will be screened and collected by two reviewers independently. RevMan V.5.3.5 software will be used for meta-analysis, and the conduction of study will refer to the Cochrane Handbook for Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines. The efficacy and safety of acupuncture for rGORD will be evaluated based on outcomes, including global symptom improvement, oesophageal sphincter function test measured by high-resolution manometry, quality of life, recurrence rate and adverse events.

ETHICS AND DISSEMINATION

There is no necessity for this study to acquire an ethical approval, and this review will be disseminated in a peer-reviewed journal or conference presentation.

TRIAL REGISTRATION NUMBER

CRD42018111912.

Central and Peripheral Mechanism of Acupuncture Analgesia on Visceral Pain: A Systematic Review

Background/Aims

Despite the wide use of acupuncture for the management of visceral pain and the growing interest in the pathophysiology of visceral pain, there is no conclusive elucidation of the mechanisms behind the effects of acupuncture on visceral pain. This systematic review aims to provide an integrative understanding of the treatment mechanism of acupuncture for visceral pain.

Methods

Electronic and hand searches were conducted to identify studies that involved visceral pain and acupuncture.

Results

We retrieved 192 articles, out of which 46 studies were included in our review. The results of our review demonstrated that visceral pain behaviors were significantly alleviated in response to acupuncture treatment in groups treated with this intervention compared to in sham acupuncture or no-treatment groups. Changes in the concentrations of β-endorphin, epinephrine, cortisol, and prostaglandin E2 in plasma, the levels of c-Fos, substance P, corticotropin-releasing hormone, P2X3, acetylcholinesterase (AchE), N-methyl-D-aspartate (NMDA) receptors, and serotonin in the gut/spinal cord, and the neuronal activity of the thalamus were associated with acupuncture treatment in visceral pain.

Conclusions

Acupuncture reduced visceral pain behavior and induced significant changes in neuronal activity as well as in the levels of pain/inflammation-related cytokines and neurotransmitters in the brain-gut axis. Further researches on the thalamus and on a standard animal model are warranted to improve our knowledge on the mechanism of acupuncture that facilitates visceral pain modulation.

Electroacupuncture and Moxibustion Improved Anxiety Behavior in DSS-Induced Colitis Mice

Background and Aims

Psychological disorders are prevalent in patients with inflammatory bowel disease, but the underlying mechanisms remain unknown. The aim of this study was to study whether electroacupuncture (EA) and moxibustion (MB) can improve anxiety behavior in DSS-induced colitis mice and to investigate whether this effect is related to hypothalamic-pituitary-adrenocortical (HPA) axis.

Methods

The colitis model was established by drinking 2.5% dextran sodium sulfate (DSS). DSS-induced colitis mice were treated by EA or MB. Disease activity index (DAI) was scored; intestinal morphological and pathological structure was observed; anxiety behavior was tested by the elevated plus maze and open field. The concentration of corticotropin-releasing hormone (CRH) and cortisol (CORT) in serum was measured by enzyme-linked immunosorbent assay (ELISA). The protein expression of CRH in the colon and hypothalamus was detected by Western blot (WB).

Results

Both EA and MB treatments can improvethe morphology of their distal colonic mucosal epithelia, as well as the disease activity index. Meanwhile, anxiety behavior in colitis mice was improved slightly after EA and MB treatment. In addition, the levels of CRH and CORT in the serum were slightly improved after EA and MB treatment. These effects are further supported by WB results. The expression of CRH in the colon and hypothalamus was increased significantly after treatment, compared with the model group.

Conclusion

EA and MB were able to regulate the concentration of CRH in serum and protein expression in the peripheral and central at different levels and promote the recovery of the HPA axis that may be the basis for EA and MB to improve colonic pathology and alleviate anxiety behavior in DSS-induced colitis.

Inhibition of electroacupuncture on nociceptive responses of dorsal horn neurons evoked by noxious colorectal distention in an intensity-dependent manner

Background

The transmission of visceral nociception can be inhibited by electroacupuncture (EA) at the spinal level. However, relationships between current intensity and EA-induced analgesia are still lacking. This study compares the effects of different intensities of EA at local acupoints and heterotopic acupoints on nociceptive responses of spinal wide dynamic range (WDR) neurons induced by noxious colorectal distension (CRD).

Materials and methods

Experiments were conducted on 40 Sprague Dawley rats anesthetized with 10% urethane. Discharges of WDR neurons in the L1–L3 segments of the dorsal horn of the spinal cord were recorded extracellularly by glass micropipettes. Different intensities of EA (0.5, 1, 2, 4, 6, and 8 mA, 0.5 ms, 2 Hz) were applied to contralateral “Zusanli” (ST 36) or “Neiguan” (PC 6), with either the same or different segmental innervation of the colon.

Results

In local acupoints, the increased discharges of WDR neurons evoked by CRD were significantly inhibited by EA at 0.5–8 mA. A positive relationship between current intensity and the inhibiting rate was observed within 0.5–4 mA, but the inhibiting rate reached a plateau when EA exceeded 4 mA. In heterotopic acupoints, the increased discharges of WDR neurons evoked by CRD were significantly inhibited by EA at 2–8 mA. A positive relationship between current intensity and the inhibiting rate was observed within 2–6 mA. Further increase in the current beyond 6 mA also resulted in a plateau effect.

Conclusion

Within a certain range, the nociceptive responses of dorsal horn neurons induced by CRD could be inhibited by EA in an intensity-dependent manner.

Acupuncture for the Treatment of Gastro-Oesophageal Reflux Disease: A Systematic Review and Meta-Analysis

Background

Gastro-oesophageal reflux disease (GORD) is one of the most common diseases presenting to gastroenterology clinics. Acupuncture is widely used as a complementary and alternative treatment for patients with GORD.

Objective

To explore the effectiveness of acupuncture for the treatment of GORD.

Methods

Four English and four Chinese databases were searched through June 2016. Randomised controlled trials investigating the effectiveness of manual acupuncture or electroacupuncture (MA/EA) for GORD versus or as an adjunct to Western medicine (WM) were selected. Data extraction and quality evaluation were performed by two authors independently and RevMan 5.2.0 was used to analyse data.

Results

A total of 12 trials involving 1235 patients were included. Meta-analyses demonstrated that patients receiving MA/EA combined with WM had a superior global symptom improvement compared with those receiving WM alone (relative risk (RR) 1.17, 95% CI 1.09 to 1.26; p=0.03; six studies) with no significant heterogeneity (I2=0%, p=0.41). Recurrence rates of those receiving MA/EA alone were lower than those receiving WM (RR 0.42,95% CI 0.29 to 0.61; p<0.001; three studies) with low heterogeneity (I2=7%, p=0.34), while global symptom improvement (six studies) and symptom scores (three studies) were similar (both p>0.05). Descriptive analyses suggested that acupuncture also improves quality of life in patients with GORD.

Conclusion

This meta-analysis suggests that acupuncture is an effective and safe treatment for GORD. However, due to the small sample size and poor methodological quality of the included trials, further studies are required to validate our conclusions.

Trial registration number

PROSPERO Systematic review registration no. CRD42016041916.

Electroacupuncture Relieves Visceral Hypersensitivity by Inactivating Protease-Activated Receptor 2 in a Rat Model of Postinfectious Irritable Bowel Syndrome

Background

The role of protease-activated receptor 2 (PAR2) in the analgesic effect of electroacupuncture (EA) on visceral hypersensitivity (VH) in postinfectious irritable bowel syndrome (PI-IBS) has yet to be elucidated.

Aim

In this study, we investigated the molecular mechanisms underlying the analgesic effect of EA in a rat model of PI-IBS.

Methods

Visceral hypersensitivity was evaluated by the abdominal withdrawal reflex test before and after administration of the PAR2 agonist, PAR2-AP, and/or EA. The protein expression and mRNA levels of PAR2, CGRP, SP, and TPSP in colon tissues were measured by immunofluorescence, western blot, and RT-PCR.

Results

We found that EA could alleviate VH and significantly decrease protein and mRNA levels of PAR2, TPSP, CGRP, and SP in PI-IBS rats. The analgesic effect of EA on VH was slightly reduced in the presence of PAR2-AP.

Conclusions

These results suggest that EA alleviates VH symptoms through downregulation of the levels of the TPSP/PAR2/SP/CGRP signaling axis in colon tissues in PI-IBS rats. Together, our data suggests that PAR2 plays a critical role in the analgesic effect of EA on VH in PI-IBS.

Stress-Induced Chronic Visceral Pain of Gastrointestinal Origin

Visceral pain is generally poorly localized and characterized by hypersensitivity to a stimulus such as organ distension. In concert with chronic visceral pain, there is a high comorbidity with stress-related psychiatric disorders including anxiety and depression. The mechanisms linking visceral pain with these overlapping comorbidities remain to be elucidated. Evidence suggests that long term stress facilitates pain perception and sensitizes pain pathways, leading to a feed-forward cycle promoting chronic visceral pain disorders such as irritable bowel syndrome (IBS). Early life stress (ELS) is a risk-factor for the development of IBS, however the mechanisms responsible for the persistent effects of ELS on visceral perception in adulthood remain incompletely understood. In rodent models, stress in adult animals induced by restraint and water avoidance has been employed to investigate the mechanisms of stress-induce pain. ELS models such as maternal separation, limited nesting, or odor-shock conditioning, which attempt to model early childhood experiences such as neglect, poverty, or an abusive caregiver, can produce chronic, sexually dimorphic increases in visceral sensitivity in adulthood. Chronic visceral pain is a classic example of gene × environment interaction which results from maladaptive changes in neuronal circuitry leading to neuroplasticity and aberrant neuronal activity-induced signaling. One potential mechanism underlying the persistent effects of stress on visceral sensitivity could be epigenetic modulation of gene expression. While there are relatively few studies examining epigenetically mediated mechanisms involved in visceral nociception, stress-induced visceral pain has been linked to alterations in DNA methylation and histone acetylation patterns within the brain, leading to increased expression of pro-nociceptive neurotransmitters. This review will discuss the potential neuronal pathways and mechanisms responsible for stress-induced exacerbation of chronic visceral pain. Additionally, we will review the importance of specific experimental models of adult stress and ELS in enhancing our understanding of the basic molecular mechanisms of pain processing.

慢性束缚应激联合番泻叶灌胃法制备IBS-D大鼠模型的量效及时效关系评价

目的

观察不同番泻叶浓度、束缚时间及造模持续时间对腹泻型肠易激综合征(diarrhea predominant irritable bowel syndrome, IBS-D)大鼠模型造成的影响, 筛选一种较为理想的IBS-D大鼠模型制作方法.

方法

SD大鼠32只, 雌雄各半. 随机分为空白组、模型1组(0.2 g/mL番泻叶+束缚1 h)、模型2组(0.3 g/mL番泻叶+束缚1 h)、模型3组(0.2 g/mL番泻叶+束缚1.5 h), 每组8只, 雌雄各半. 以造模7、10、14 d时腹壁撤退反射时的疼痛阈值评价其内脏敏感性, 腹泻指数评价其腹泻程度, 同时对肠黏膜的组织学改变进行评价.

结果

各组模型大鼠疼痛阈值在7、10、14 d均较空白组明显降低(P<0.05); 腹泻指数在7、10、14 d均较空白组明显增加(P<0.05). 模型2组的疼痛阈值较模型1组在7 d和14 d低(均为P = 0.006), 与模型3组比较差异不明显(P = 1.000, P = 0.198); 模型2组的腹泻指数较模型1组和模型3组在3个时间点高(P<0.05). 组织学分析显示各组大鼠均无明显的炎症性表现.

结论

3种造模方法在7、10、14 d均可建立IBS-D的动物模型, 其中束缚1 h联合番泻叶0.3 g/mL灌胃的方法在内脏敏感性及腹泻指数上要优于其他两种造模方法.

Proteomics and irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a gastrointestinal disease that according to Rome IV criteria is subdivided into four subtypes. The pathophysiology of this disease is not well understood due to numerous factors playing multiple roles in disease development, such as diet, stress and hormones. IBS has a variety of symptoms and overlaps with many other gastrointestinal and non-gastrointestinal diseases. Area covered: This review aims to present an overview of implementation of proteomics in experimental studies in the field of IBS. Expert commentary: Proteomics is commonly used for biomarker discovery in and has also been extensively used in IBS research. The necessity of a sensitive and specific biomarker for IBS is apparent, but despite the intensive research performed in this field, an appropriate biomarker is not yet available.

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.