Effect of "needle sensation" and the real-time changes in autonomic nervous system activity during acupuncture analgesia.

Introduction: Acupuncture analgesia (AA) is widely used in clinical practice. The autonomic nervous system (ANS) may be an important pathway for acupuncture signal transduction. However, real-time changes in autonomic function during AA and the effect of "needle sensation" remain unclear. Methods: We established a human pain model in healthy adults and randomly assigned 128 participants to the model, sham acupuncture, and acupuncture groups in a 1:1:2 ratio. Heart rate variability (HRV), including total power (TP), low-frequency power (LF), high-frequency power (HF), ratio of LF to HF (LF/HF), standard deviation of the normal-normal intervals (SDNN), and root mean square of successive interval differences (RMSSD), were used to assess autonomic function. The visual analog scale (VAS) and efficiency were used to assess the analgesic effect of acupuncture. The Massachusetts General Hospital acupuncture sensation scale (MASS) was used to indicate the intensity of the needle sensation. Anxiety levels were also measured. Finally, the correlation of MASS with HRV, VAS, and anxiety levels was analyzed. Results: VAS decreased after 10 min of needling and 5 min after needle withdrawal in the acupuncture group compared with those in the model group (p = 0.038, p = 0.020). The efficacy rates were 82.0, 50.0, and 61.3% in the acupuncture, model, and sham groups, respectively. These represent significant differences between the acupuncture group and the model and sham acupuncture groups (p < 0.001 in each case). No differences were observed between the model and sham acupuncture groups. HF, TP, SDNN, and RMSSD were all increased in the acupuncture group compared with those in the model group (p = 0.045, p = 0.041, p = 0.002, p = 0.006, respectively). No differences were observed in the sham acupuncture group compared to the model group (p = 0.632, p = 0.542, p = 0.093, p = 0.222, respectively). The LF and LF/HF did not differ among all three groups. A positive correlation was observed between MASS and RMSSD2, LF2, RMSSD4, TP4, VAS5, and anxiety levels. Conclusion: AA was associated with enhanced vagal activity. The intensity of needle sensation was positively correlated with vagal and sympathetic nerve activities. Acupuncture is an effective means of regulating autonomic function, and needle sensation may be an important modulator.

Acupuncture alleviates inflammatory pain by activating CXCL1/CXCR2 signaling in the primary somatosensory cortex in adjuvant induced arthritis rats. / S1脑区CXCL1/CXCR2å‚ä¸Žé’ˆåˆºæ”¹å–„ä½å‰‚æ€§å ³èŠ‚ç‚Žå¤§é¼ ç‚Žæ€§ç—›çš„ä½œç”¨æœºåˆ¶.

OBJECTIVES: To observe whether acupuncture up-regulates chemokine CXC ligand 1 (CXCL1) in the brain to play an analgesic role through CXCL1/chemokine CXC receptor 2 (CXCR2) signaling in adjuvant induced arthritis (AIA) rats, so as to reveal its neuro-immunological mechanism underlying improvement of AIA. METHODS: BALB/c mice with relatively stable thermal pain reaction were subjected to planta injection of complete Freund adjuvant (CFA) for establishing AIA model, followed by dividing the AIA mice into simple AF750 (fluorochrome) and AF750+CXCL1 groups (n=2 in each group). AF750 labeled CXCL1 recombinant protein was then injected into the mouse's tail vein to induce elevation of CXCL1 level in blood for simulating the effect of acupuncture stimulation which has been demonstrated by our past study. In vivo small animal imaging technology was used to observe the AF750 and AF750+CXCL1-labelled target regions. After thermal pain screening, the Wistar rats with stable pain reaction were subjected to AIA modeling by injecting CFA into the rat's right planta, then were randomized into model and manual acupuncture groups (n=12 in each group). Other 12 rats that received planta injection of saline were used as the control group. Manual acupuncture (uniform reinforcing and reducing manipulations) was applied to bilateral "Zusanli" (ST36) for 4×2 min, with an interval of 5 min between every 2 min, once daily for 7 days. The thermal pain threshold was assessed by detecting the paw withdrawal latency (PWL) using a thermal pain detector. The contents of CXCL1 in the primary somatosensory cortex (S1), medial prefrontal cortex, nucleus accumbens, amygdala, periaqueductal gray and rostroventromedial medulla regions were assayed by using ELISA, and the expression levels of CXCL1, CXCR2 and mu-opioid receptor (MOR) mRNA in the S1 region were detected using real time-quantitative polymerase chain reaction. The immune-fluorescence positive cellular rate of CXCL1 and CXCR2 in S1 region was observed after immunofluorescence stain. The immunofluorescence double-stain of CXCR2 and astrocyte marker glial fibrillary acidic protein (GFAP) or neuron marker NeuN or MOR was used to determine whether there is a co-expression between them. RESULTS: In AIA mice, results of in vivo experiments showed no obvious enrichment signal of AF750 or AF750+CXCL1 in any organ of the body, while in vitro experiments showed that there was a stronger fluorescence signal of CXCL1 recombinant protein in the brain. In rats, compared with the control group, the PWL from day 0 to day 7 was significantly decreased (P<0.01) and the expression of CXCR2 mRNA in the S1 region significantly increased in the model group (P<0.05), while in comparison with the model group, the PWL from day 2 to day 7, CXCL1 content, CXCR2 mRNA expression and CXCR2 content, and MOR mRNA expression in the S1 region were significantly increased in the manual acupuncture group (P<0.05, P<0.01). Immunofluorescence stain showed that CXCR2 co-stained with NeuN and MOR in the S1 region, indicating that CXCR2 exists in neurons and MOR-positive neurons but not in GFAP positive astrocytes. CONCLUSIONS: Acupuncture can increase the content of CXCL1 in S1 region, up-regulate CXCR2 on neurons in the S1 region and improve MOR expression in S1 region of AIA rats, which may contribute to its effect in alleviating inflammatory pain.

NTPDase1-ATP-P2Y2Rs axis in the sciatic nerve contributes to acupuncture at "Zusanli" (ST36)-induced analgesia in ankle arthritis rats.

BACKGROUND: The efficacy of acupuncture at Zusanli (ST36) in alleviating lower-limb pain is widely acknowledged in clinical practice, while its underlying mechanism remains incompletely elucidated. Our previous research had revealed that the prompt analgesia induced by needling-ST36 was accompanied by expression alterations in certain exco-nucleotidases within the sciatic nerve. Building upon this finding, the current work focused on NTPDase1, the primary ecto-nucleotidase in the human body, which converts ATP into AMP. METHODS: A 20-min acupuncture was administered unilaterally at the ST36 on rats with acute ankle arthritis. The pain thresholds of the injured hind paws were determined. Pharmacological interference was carried out by introducing the corresponding reagents to the sciatic nerve. ATP levels around the excised nerve were measured using a luciferase-luciferin assay. Live calcium imaging, utilizing the Fura 2-related-F340/F380 ratio, was conducted on Schwann cells in excised nerves and cultured rat SCs line, RSC96 cells. RESULTS: The analgesic effect induced by needling-ST36 was impaired when preventing ATP degradation via inhibiting NTPDase1 activities with ARL67156 or Ticlopidine. Conversely, increasing NTPDase1 activities with Apyrase duplicated the acupuncture effect. Similarly, preventing the conversion of AMP to adenosine via suppression of NT5E with AMP-CP hindered the acupuncture effect. Unexpectedly, impeded ATP hydrolysis ability and diminished NTPDase1 expression were observed in the treated group. Agonism at P2Y2Rs with ATP, UTP, or INS365 resulted in anti-nociception. Contrarily, antagonism at P2Y2Rs with Suramin or AR-C 118925xx prevented acupuncture analgesia. Immunofluorescent labeling demonstrated that the treated rats expressed more P2Y2Rs that were predominant in Schwann cells. Suppression of Schwann cells by inhibiting ErbB receptors also prevented acupuncture analgesia. Finally, living imaging on the excised nerves or RSC96 cells showed that agonism at P2Y2Rs indeed led to [Ca2+]i rise. CONCLUSION: These findings strongly suggest that the analgesic mechanism of needling-ST36 on the hypersensation in the lower limb partially relies on NTPDase1 activities in the sciatic nerve. In addition to facilitating adenosine signaling in conjunction with NT5E, most importantly, NTPDase1 may provide an appropriate low-level ATP milieu for the activation of P2Y2R in the sciatic nerve, particularly in Schwann cells.

Understanding of Spinal Wide Dynamic Range Neurons and Their Modulation on Pathological Pain.

The spinal dorsal horn (SDH) transmits sensory information from the periphery to the brain. Wide dynamic range (WDR) neurons within this relay site play a critical role in modulating and integrating peripheral sensory inputs, as well as the process of central sensitization during pathological pain. This group of spinal multi-receptive neurons has attracted considerable attention in pain research due to their capabilities for encoding the location and intensity of nociception. Meanwhile, transmission, processing, and modulation of incoming afferent information in WDR neurons also establish the underlying basis for investigating the integration of acupuncture and pain signals. This review aims to provide a comprehensive examination of the distinctive features of WDR neurons and their involvement in pain. Specifically, we will examine the regulation of diverse supraspinal nuclei on these neurons and analyze their potential in elucidating the mechanisms of acupuncture analgesia.

Advances in the study of endocannabinoid receptors in experimental acupuncture analgesia. / å† æºæ€§å¤§éº»ç´ å—ä½“åœ¨é’ˆåˆºé•‡ç—›æœºåˆ¶ä¸­çš„ç ”ç©¶è¿›å±•.

The endocannabinoid system, an important biological network for maintaining and balancing various functions of the human body, is involved in many physiological functions such as pain, emotion, learning and memory, etc. Among which the endocannabinoid receptors ï¼»including type I (CB1) and type II (CB2) receptorsï¼½ play an important role in the regulation of pain and have become an important target in the mechanism research of acupuncture analgesia. CB1 is mainly distributed in the central nervous system, including the spinal cord, cerebral cortex, amygdala, insular cortex, and basal ganglia, etc. CB2 is mainly distributed in peripheral immune tissues, such as spleen, bone, skin, etc. In the central and peripheral nervous systems, acupuncture can activate CB1 and CB2 receptors respectively, which is involved in the transmission of central nociceptive signals and related transmitters as well as the peri-pheral pro-nociceptive inflammatory response, thereby alleviating the nociceptive hypersensitivity in animal models. In this paper, we systematically summarize the roles of the above mechanisms in different types of animal models (inflammatory pain, neuropathological pain, visceral pain, etc.), so as to provide new ideas for the study of the underlying mechanisms of acupuncture analgesia.

Dry needling, trigger point electroacupuncture and motor point electroacupuncture for the treatment of myofascial pain syndrome involving the trapezius: a randomised clinical trial.

OBJECTIVE: The objective of this study was to compare trigger point (TrP) dry needling, TrP electroacupuncture and motor point electroacupuncture of the trapezius muscle for the treatment of myofascial pain syndrome (MPS). METHODS: This randomised clinical trial included 90 patients divided into three groups. Group 1 was treated with dry needling of TrPs, group 2 with intramuscular electrical stimulation of TrPs, and group 3 with electroacupuncture of motor points and/or the spinal accessory nerve. Each group received seven treatment sessions. The outcomes were the pain score measured by visual analogue scale (VAS) and quality of life evaluated by the 12-item short form (SF-12) health questionnaire. We compared the pain outcome over serial time points using growth curve analysis methods. RESULTS: Participants in the three groups experienced significant improvements in pain scores over time. The average pain level of participants in group 3 across the repeated assessments was 0.98 units lower than in group 1 (mean difference (95% confidence interval (CI) = 1.74-0.23)), p = 0.012). There were no significant differences in pain scores between participants in groups 1 and 2, and there were no significant differences in quality of life across the three groups at the end of the treatment period. CONCLUSION: Our results provide evidence that electrical stimulation of motor points and/or of the spinal accessory nerve may be superior in terms of pain relief (but not quality of life) to dry needling and possibly electrical stimulation of trigger points for the management of MPS involving the trapezius. TRIAL REGISTRATION NUMBER: TRIAL-RBR-43R7RF (Brazilian Clinical Trials Registry).

Clinical study of acupuncture combined with surface anesthesia using proparacaine in geriatric cataract phacoemulsification.

BACKGROUND: During anesthesia administration for cataract surgery, low pH of proparacaine may induce pain or complications such as corneal damage and poor wound healing, with the use of additional drops intraoperatively increasing the risk of complications. Accordingly, there is a clinical need for adjuncts to local anesthesia needs to improve the efficiency of anesthesia and reduce the required amount of intraoperative proparacaine. AIM: To identify a method of anesthesia for geriatric cataract phacoemulsification that provides more efficient analgesia and improves clinical efficacy. METHODS: A total of 130 geriatric patients with cataracts who attended Hebei Eye Hospital from December 2020 to December 2022 were included in the present study. Patients were divided into the proparacaine surface anesthesia (SA) group (65 cases) and the compound acupuncture-medicine anesthesia group (CAMA group, 65 cases). Patients in the CAMA group were provided acupuncture analgesia in addition to SA. Preoperative anxiety [Self-Rating Anxiety Scale (SAS) score and state anxiety inventory (SAI) score], intraoperative stress, vital signs, analgesia, and cooperation, as well as postoperative adverse events, were compared between groups. RESULTS: More marked reductions in anxiety were observed among patients in the CAMA group, with corresponding reductions in SAS and SAI scores. During the operation, no change in the secretion of E, NE, or Cor group compared to the preoperative period was observed in the CAMA, which was markedly lower than that in the SA group. Heart rate, blood pressure, and respiratory rate were more stable intraoperatively in the CAMA group. In addition, the incidence of intraoperative pain and the number of additional doses of anesthesia required in the CAMA group were markedly lower than in the SA group. Accordingly, patients in the CAMA group were able to avoid eye movements and eyelid closing leading to greater cooperation with surgeons during surgery. Furthermore, marked reductions in intraoperative adverse effects were observed in the CAMA group, indicating greater overall safety. CONCLUSION: Proparacaine SA combined with acupuncture as an analgesic provides improved analgesia with greater safety compared to surface anesthesia with proparacaine during geriatric cataract phacoemulsification.

Bibliometric Analysis of Acupuncture Therapy for Cancer Pain Over the Past 10 Years.

Purpose: Cancer pain is a common symptom of cancer patients and greatly affects quality of life. Acupuncture has certain curative effects on cancer pain. The aim of this study was to analyze and visualize the current status and research trend of acupuncture treatment for cancer pain over the last 10 years and provide directions for future development. Methods: A search of the Web of Science Core Collection from 2012-01-01 to 2022-08-20 was performed to collect studies related to acupuncture therapy for cancer pain. CiteSpace was used to conduct bibliometric analysis and visualization from the perspective of the volume of annual publications, journals, nations, institutions, authors, keywords, and references. Results: A total of 302 studies were included in the analysis. The number of publications increased steadily with some fluctuations over the past decade. Integrative Cancer Therapies was the journal with the most relevant publications, and the Journal of Clinical Oncology was the most frequently cited journal. China had the highest volume of publications, and the USA contributed most to international collaboration. The most prolific institution was Memorial Sloan Kettering Cancer Center. The most productive author was Mao JJ, and the most influential author was Lu WD. "Acupuncture" was the top keyword in frequency and centrality. The references with the highest frequency and centrality were published by HE, Y, and Ting Bao, respectively. Conclusion: A stable development trend has formed in this field. The overall collaborative network needs to be strengthened. Breast cancer and multiple myeloma, electroacupuncture and bee venom acupuncture, postoperative pain, peripheral neuropathic pain syndrome, and aromatase inhibitors-associated arthralgia syndrome are research hotspots in this field. Randomized controlled trials (RCTs), evidence-based evaluations and mechanisms (cancer-induced bone pain) are research trends and frontiers.

Mast Cell-Associated Serotonin in Acupoint Contributes to Acupuncture Analgesia in Arthritis Rats by Mediating ATP Release.

BACKGROUND: The activation of subcutaneous mast cells (MCs) helps to trigger the analgesic effect induced by acupuncture (AP), a traditional oriental therapy, that has been gradually accepted worldwide. This work aimed to reveal whether the serotonin (5-hydroxytryptamine, 5-HT) released from MCs plays an important role in this process, which has a controversial effect in the mechanism of pain. METHODS: In vivo tests, a 20-min session of AP was applied at Zusanli acupuncture point (acupoint) of acute ankle arthritis rats. Pain thresholds of the injured hindpaw were assessed to reflect the pain state, and the targeting substances in the interstitial space of the treated acupoint were sampled by microdialysis. In vitro experiments, exogenous 5-HT (exo-5-HT) was introduced to mediate adenosine triphosphate (ATP) release from cultured MCs. RESULTS: Needling promoted 5-HT accumulation at the Zusanli acupoint, which was prevented by sodium cromolyn. AP's analgesic effect was suppressed by the inhibition of 5-HT receptors at the acupoint, especially 5-HT1A subtype. In vitro tests, mechanical perturbation mimicking needling stimulation induced MCs to release 5-HT. 1 µM and 10 µM of exo-5-HT facilitated ATP release, which was restrained by blocking of 5-HT1 receptors rather than 5-HT3 receptors. As 5-HT, ATP and adenosine were also transiently accumulated in the treated acupoint during needling. Promoting ATP hydrolysis or activation adenosine A1 receptors duplicated AP analgesic effect. Finally, the inhibition of ATP receptors by suramin or pyridoxal phosphate-6-azo tetrasodium salt hydrate (PPADS) prevented AP analgesic effect. CONCLUSIONS: Our results suggest that MC-associated 5-HT release at acupoints contributes to AP analgesia, and the mediation of ATP secretion through 5-HT1A receptors might be the underlying mechanism at play. ATP could facilitate adenosine production or the propagation of needling signals.

The real-time detection of acupuncture-induced extracellular ATP mobilization in acupoints and exploration of its role in acupuncture analgesia.

Our and in vitro studies had confirmed that mechanosensitive ATP release and accumulation in acupoints was elicited by acupuncture (AP), which might be a pivotal step for triggering AP analgesia. But to date, the dynamics of extracellular ATP (eATP) in the interstitial space during AP process was poorly known, mainly due to the low temporal resolution of the current detection approach. This study attempted to capture rapid eATP signals in vivo in the process of needling, and further explored the role of this eATP mobilization in initiating AP analgesic effect. Ipsilateral 20-min needling was applied on Zusanli acupoint (ST36) of complete Freund's adjuvant (CFA)-induced ankle arthritis rats. Pain thresholds were assessed in injured-side hindpaws. eATP in the interstitial space was microdialyzed and real-time quantified by luciferin-luciferase assay at 1-min interval with the aid of the microfluid chip. We revealed in behavioral tests that modulation of eATP levels in ST36 influenced AP analgesic effect on ankle arthritis. A transient eATP accumulation was induced by needling that started to mobilize at 4 min, climbed to the peak of 11.21 nM within 3.25 min and gradually recovered. Such AP-induced eATP mobilization was significantly impacted by ankle inflammation, needling depth, needle manipulation, and the presence of local ecto-nucleotidases. This work reveals that needling elicits a transient eATP mobilization in acupoints, which contributes to initiating AP analgesia. This study will help us better understand the peripheral mechanism of AP analgesia and guide clinicians to optimize the needle manipulations to improve AP efficacy.

The role of visual expectations in acupuncture analgesia: A quantitative electroencephalography study.

Acupuncture is a complex treatment comprising multisensory stimulation, including visual and tactile sensations and experiences of body ownership. The purpose of this study was to investigate the role of these three components of acupuncture stimulation in acupuncture analgesia. 40 healthy volunteers participated in the study and received acupuncture treatment under three different conditions (real-hand, rubber-hand synchronous, and rubber-hand asynchronous). The tolerance for heat pain stimuli was measured before and after treatment. Brain oscillation changes were also measured using electroencephalography (EEG). The pain tolerance was significantly increased after acupuncture treatment under all three conditions. Noticeable deqi (needle) sensations in response to acupuncture stimulation of the rubber hand were found under both rubber-hand synchronous and rubber-hand asynchronous conditions. Deqi sensations were significantly correlated with acupuncture analgesia only under the rubber-hand synchronous condition. Increased delta and decreased theta, alpha, beta, and gamma waves were observed after acupuncture treatment under all three conditions. Our findings clarified the role of cognitive components of acupuncture treatment in acupuncture analgesia through the rubber-hand illusion. This study is a first step toward separating various components of acupuncture analgesia, i.e. visual, tactile, and body ownership, and utilizing those components to maximize analgesic effects.

The Application of Acupuncture Therapy for Postoperative Pain Over the Past 20 Years: A Bibliometric Analysis.

Purpose: The purpose of this study is to analyze and visualize the research trends on acupuncture therapy for postoperative pain over the past 20 years to identify hotspots and frontiers, and provide new research ideas. Methods: A search of the Web of Science database, with a time frame of 2001-01-01 to 2022-02-28, was conducted to collect literatures related to acupuncture therapy for postoperative pain. A bibliometric analysis and visualization of results was performed using CiteSpace software for the volume of annual publications, journals, countries, institutions, authors, keywords, and references. Results: A total of 840 literatures were eventually included in the analysis. The number of publications has fluctuated upwards each year over the past 20 years and reached a peak in the latest three years. Evidence-Based Complementary and Alternative Medicine was the journal with the most relevant publications and Pain was the most frequently cited journal. The country with the highest volume of publications was China, and the USA contributed most to the international collaboration. The most prolific and influential authors were Inhyunk Ha and Han JS respectively. The most frequent keyword was "acupuncture". References with highest frequency or centrality were both systematic evaluations focusing on different acupuncture therapies for postoperative pain relief. Conclusion: The field of acupuncture therapy for postoperative pain is currently in a period of high growth. China and the USA have made the largest contribution to the volume of publications. The most influential institutions and authors are mainly from China and South Korea. The overall collaborative network needs to be strengthened. Electroacupuncture and auricular acupuncture (therapeutic techniques), low back surgery (types of surgery), and "postoperative pain, nausea and vomiting" are research hotspots in this field. Improvement of postoperative life quality, proof of clinical efficacy and evidence-based evaluation are the current research trends and frontiers.

Acupuncture Analgesia in Patients With Traumatic Rib Fractures: A Randomized-Controlled Trial.

Pain management for traumatic rib fracture is important to prevent complications and reduce associated comorbidities. This trial investigated the analgesic efficacy of acupuncture on traumatic rib fracture. Patients with traumatic rib fracture were randomly assigned to traditional acupuncture (TA), laser acupuncture (LA) or sham laser acupuncture (SLA) groups in a 1:1:1 ratio. The intervention was performed on days 1 to 3 after treatment allocation. The acupoints included bilateral LI4 (Hegu), SJ6 (Zhigou), ST36 (Zusanli) and GB34 (Yanglingquan). The primary outcome was Numeric Rating Scale (NRS) scores for pain after the intervention. Secondary outcomes included sustained maximal inspiration (SMI) lung volume, stress responses, the use of analgesics, and associated complications. Data were analyzed via one-way analysis of variance (ANOVA) with Scheffé's post hoc testing or chi-squared testing. Of the 120 study participants, 109 completed all interventions and measurements. The primary outcomes, which indicated average pain intensity levels and pain while deep breathing, were both significantly lower in the TA and LA groups than in the SLA group after 2 treatments. No between-group differences were observed in SMI lung volume, stress response, analgesics use or associated complications. These findings suggest that TA and LA are safe and effective analgesic modalities for pain management for traumatic rib fracture. Clinical Trial Registration: [ClinicalTrials.gov], identifier [NCT03822273].

Using a consensus acupoints regimen to explore the relationship between acupuncture sensation and lumbar spinal postoperative analgesia: A retrospective analysis of prospective clinical cooperation.

OBJECTIVE: This study evaluated the effectiveness of acupuncture treatment on postoperative pain in patients with degenerative lumbar spine disease, and explored the relationship between the postoperative analgesic effect of acupuncture and the sensation of acupuncture experienced by the patients. METHODS: This retrospective study analyzed the medical records of 97 patients who had undergone an operation by the same surgeon due to degenerative lumbar disease. These patients were divided into acupuncture group (n = 32), patient-controlled analgesia (PCA) group (n = 27), and oral analgesia group (n = 38) according to the different postoperative analgesic methods. During their hospitalization, patients completed daily evaluations of their pain using a visual analogue scale (VAS), and injection times of supplemental meperidine were recorded. Also, the Chinese version of the Massachusetts General Hospital Acupuncture Sensation Scale (C-MASS) was used in the acupuncture group. RESULTS: Each of the three treatment groups showed significant reductions in postoperative pain, as shown by reduced VAS scores. The acupuncture group, however, had less rebound pain (P < 0.05) than the other two groups. Both the acupuncture and PCA groups experienced acute analgesic effects that were superior to those in the oral analgesia group. In addition, the higher the C-MASS index on the second day after surgery, the lower the VAS score on the fourth day after surgery. There was also a significant difference in the "dull pain" in the acupuncture sensation. CONCLUSION: The results demonstrated that acupuncture was beneficial for postoperative pain and discomfort after simple surgery for degenerative spinal disease. It is worth noting that there was a disproportionate relevance between the patient's acupuncture sensation and the improvement of pain VAS score.

Mast Cells and Acupuncture Analgesia.

Mast cells are widely distributed in various parts of the human body and play a vital role in the progression of many diseases. Recently, the close relationship between mast cells and acupoints was elucidated, and the role of mast cells in acupuncture analgesia has attracted the attention of researchers worldwide. Using mast cells, acupuncture analgesia and acupoint as key words to search CNKI, PubMed, Web of Science and other databases, combining the representative articles in these databases with the published research papers of our group, we summarized: The enrichment of mast cells and the dense arrangement of collagen fibers, microvessels, and nerves form the basis for acupoints as the reaction sites of acupuncture; acupuncture can cause the deformation of collagen fibers and activate TRPV channels on mast cells membrane, so as to stimulate mast cells to release bioactive substances and activate nerve receptors to generate analgesic effect; system biology models are set up to explain the quantitative process of information initiation and transmission at acupuncture points, and indicate that the acupuncture effect depends on the local mast cells density. In a conclusion, this review will give a scientific explanation of acupuncture analgesia from the material basis of acupoints, the local initiation, and afferent biological mechanism.

Analgesic effect of acupuncture in patients with stable angina: integrative review / Efeito analgésico da acupuntura em pacientes com angina estável: revisão integrativa

ABSTRACT BACKGROUND AND OBJECTIVES: Angina is a clinical syndrome characterized by pain or discomfort, considered stable when it occurs for several weeks without progressing to an acute coronary event. Anginal pain management can be performed with pharmacological and non-pharmacological treatments, among which acupuncture is a non-pharmacological option. The aim of this study was to carry out an integrative review of the analgesic effect of acupuncture in patients with stable angina. CONTENTS: An integrative review was carried out in April 2021 in databases: Pubmed, Scopus, Cinahl and Bireme. Controlled descriptors "angina pectoris", "angina stable", "acupuncture", "acupuncture therapy", "acupuncture analgesia" were used. After screening and analyzing the manuscripts, seven experimental studies of the randomized controlled trial type were selected. The results suggest that acupuncture in patients with stable angina can promote an analgesic effect with clinical improvement of symptoms. CONCLUSION: Acupuncture can be an adjuvant therapeutic alternative for the treatment of patients with stable angina, since it can promote an analgesic effect with clinical improvement of symptoms.

RESUMO JUSTIFICATIVA E OBJETIVOS: A angina é uma síndrome clínica caracterizada por dor ou desconforto, considerada estável quando ocorre por várias semanas sem evoluir para um evento coronariano agudo. O manejo da dor anginosa pode ser realizado por meio de tratamentos farmacológicos e não farmacológicos, incluindo a acupuntura como uma opção não farmacológica complementar. O objetivo deste estudo foi realizar uma revisão integrativa sobre o efeito analgésico da acupuntura em pacientes com angina estável. CONTEÚDO: Foi realizada uma revisão integrativa no mês de abril de 2021 nas bases de dados: Pubmed, Scopus, Cinahl e Bireme. Foram utilizados os descritores controlados "angina pectoris", "angina stable", "acupuncture", "acupuncture therapy", "acupuncture analgesia". Após triagem e análise dos manuscritos, foram selecionados sete estudos experimentais do tipo ensaio controlado randomizado. Os resultados sugerem que a acupuntura pode promover efeito analgésico com melhora clínica dos sintomas em pacientes com angina estável. CONCLUSÃO: A acupuntura pode ser uma alternativa terapêutica complementar para tratamento de pacientes com angina estável, uma vez que pode promover efeito analgésico com melhora clínica dos sintomas.

[κ-opioid receptor is involved in electroacupuncture analgesia via inhibition of spinal microglial Toll-like receptor 4 in neuropathic pain rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of lumbar spinal κ-opioid receptor (KOR) and Toll-like receptor 4(TLR4) in microglia in neuropathic pain rats, so as to explore the role of cross-talk between KOR and TLK4 in EA-induced alleviation of chronic neuropathic pain. METHODS: Wistar male rats were randomized into control, model, EA and EA plus KOR inhibitor (EA+inhibitor) groups (n=18 in each group). The neuropathic pain model was established in rats by ligature of the right sciatic nerve. EA was applied at bilateral "Zusanli"(ST36) and "Yanglingquan"(GB34) for 30 min, once daily for 5 days. JDTic dihydrochloride (a KOR inhibitor) was administrated by intraperitoneal injection before EA intervention. The difference value of paw withdrawal thermal latency (PWLD) of the bilateral hind-limbs was used as the thermal pain reaction level. At the end of experiments, the rat's lumbar spinal cord (L2-L4) was taken for detecting the expression of CD68 mRNA (a marker of the activated microglia) and Iba-1 (a marker for the activated and resting microglia) immunoactivity, and dynorphin content, and KOR mRNA and TLR4 protein (in immunomagnetic microbead method separated microglia) by using fluorescence quantitative PCR, immunofluorescence, radioimmunoassay and Western blot, separately. RESULTS: Compared with the control group, a strong thermal hyperalgesia was induced, the expression levels of Iba-1 and CD68 mRNA in the spinal cord, TLR4 protein of the spinal microglia were significantly increased(P<0.01) in the model group. The microglia were characterized by somatic hypertrophy and thickened branches in the model group. After EA intervention, the PWLD, the expression of Iba-1, CD68 mRNA and TLR4 protein of the microglia were significantly decreased(P<0.05), while the content of spinal dynorphin and the expression of KOR mRNA of the microglia increased in the EA group relative to the model group(P<0.05). The hypertrophic microglia shrinked slightly in the EA group. After injection of KOR inhibitor, the PWLD and expression levels of Iba-1, CD68 mRNA and TLR4 protein were significantly increased(P<0.05), and the expression of KOR mRNA was significantly decreased(P<0.05) in the EA+inhibitor group in comparison with the EA group. CONCLUSION: The analgesia effect of EA may partly mediated by spinal microglial KOR and the activation of KOR of microglia may be a target for inhibition of microglial TLR4-induced pro-inflammatory signaling.

Efficacy of different acupuncture therapies on postherpetic neuralgia: A Bayesian network meta-analysis.

Background: Postherpetic neuralgia (PHN) is a common, complex, and refractory type of neuropathic pain. Several systematic reviews support the efficacy of acupuncture and related treatments for PHN. Nevertheless, the efficacy of various acupuncture-related treatments for PHN remains debatable. Objective: We aimed to assess the efficacy and safety of acupuncture-related treatments for PHN, identify the most effective acupuncture-related treatments, and expound on the current inadequacies and prospects in the applications of acupuncture-related therapies. Methods: We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, Google Scholar, four Chinese databases (China National Knowledge Infrastructure, China Biomedical, Chongqing VIP, and Wan Fang databases), clinical research registration platform (World Health Organization International Clinical Trial Registration platform, China Clinical Trial Registration Center) for relevant studies. We also examined previous meta-analyses; gray literature; and reference lists of the selected studies. We then evaluated the risk of bias in the included studies and performed a Bayesian multiple network meta-analysis. Results: We included 29 randomized controlled trials comprising 1,973 patients, of which five studies showed a high risk of bias. The pairwise meta-analysis results revealed that the efficacy of all acupuncture-related treatments for pain relief related to PHN was significantly better than antiepileptics. The network meta-analysis results showed that pricking and cupping plus antiepileptics were the most effective treatment, followed by electroacupuncture (EA) plus antiepileptics for pain relief in patients with PHN. EA plus antiepileptics ranked the best regarding reduced Pittsburgh Sleep Quality Index (PSQI) and Self-Rating Depression Scale (SDS) scores in patients with PHN. No results were found regarding the total response rate or quality of life in this study. Acupuncture-related treatments showed a lower incidence of adverse events than that of antiepileptics. Conclusion: Acupuncture-related therapies are potential treatment options for PHN and are safe. Pricking and cupping plus antiepileptics, are the most effective acupuncture-related techniques for pain relief, while EA plus antiepileptics is the best acupuncture-related technique for improving PHN-related insomnia and depression symptoms. However, owing to the limitations of this study, these conclusions should be cautiously interpreted, and future high-quality studies are needed. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021226422, identifier CRD42021226422.

Adiponectin regulates electroacupuncture-produced analgesic effects in association with a crosstalk between the peripheral circulation and the spinal cord.

Neurotransmitter-mediated acupuncture analgesia has been widely studied in nervous systems. It remains largely unclear if peripheral substances are involved the acupuncture analgesia. Adiponectin (APN), a circulating adipokine, shows analgesic effects. The study aimed to examine whether APN regulates analgesic effects of electroacupuncture (EA) in the complete Freund's adjuvant (CFA)-induced mouse model. APN wild type (WT) and knockout (KO) mouse were employed in the study. We found that EA attenuates the CFA-induced pain as demonstrated by the Hargreaves thermal test and the von Frey filament test. The deletion of APN significantly reduced the acupuncture analgesia in the CFA-treated APN KO mice while the intrathecal administration of APN mimicked the analgesic effects of EA. We further revealed that EA produced analgesic effects mainly via APN/AdipoR2-mediated AMPK pathway by the siRNA inhibitions of APN receptors (adipoR1/2) in the spinal cord. The immunofluorescence staining analysis showed that EA increased the APN accumulation in spinal cord through the blood circulation. In conclusion, the study indicates a novel mechanism that acupuncture produces analgesic effects at least partially via APN/AdipoR2-AMPK pathway in the spinal cord.