Participation of Potential Transient Receptors in the Antinociceptive Effect of Pharmacopuncture.

Background: Despite the widespread clinical use of acupuncture in painful situations, the use of this treatment should be further clarified. Nociception is mediated by the activation of nociceptors, such as transient receptor potentials (TRPs). The family of TRPs includes TRPV1, TRPM8, and TRPA1, which can be stimulated by substances such as capsaicin, menthol, and methyl salicylate, respectively. Objectives: This study aimed to investigate the role of TRPs in antinociception via the administration of agonists of these receptors in the Zusanli acupoint (ST36) in models of inflammatory, acute, and neuropathic pain. Methods: Male Wistar rats were used for this experiment. All rats received a subcutaneous injection of TRP agonists (capsaicin, menthol, or methyl salicylate) in ST36; saline was injected as control. Nociception was evaluated using the electronic mechanical threshold test and tail-flick test before the administration of complete Freund's adjunct or chronic constriction injury of the sciatic nerve and after the administration of TRP agonists. Results: Nociception was found to be attenuated after treatment with TRP agonists. The administration of different doses (0.03, 0.3, and 3.0 µg/20 µL) of capsaicin, menthol, and methyl salicylate in the different pain models (neuropathic, inflammatory, and nociceptive) induced antinociception in most of the evaluated time points. Conclusion: Based on the findings, we suggest that the activation of TRPV1, TRPM8, and TRPA1 receptors results in the antinociceptive effect of the stimulation of the ST36 acupoint. Thus, TRP receptors may present a new therapeutic opportunity for the control of inflammatory and neuropathic pain.

Electroacupuncture modulates cortical excitability in a manner dependent on the parameters used.

INTRODUCTION: There is evidence that electroacupuncture (EA) acts through the modulation of brain activity, but little is known about its influence on corticospinal excitability of the primary motor cortex (M1). OBJECTIVE: To investigate the influence of EA parameters on the excitability of M1 in healthy individuals. METHODS: A parallel, double blind, randomized controlled trial in healthy subjects, evaluating the influence of an EA intervention on M1 excitability. Participants had a needle inserted at LI4 in the dominant hand and received electrical stimulation of different frequencies (10 or 100 Hz) and amplitude (sensory or motor threshold) for 20 min. In the control group, only a brief (30 s) electrical stimulation was applied. Single and paired pulse transcranial magnetic stimulation coupled with electromyography was applied before and immediately after the EA intervention. Resting motor threshold, motor evoked potential, short intracortical inhibition and intracortical facilitation were measured. RESULTS: EA increased corticospinal excitability of M1 compared to the control group only when administered with a frequency of 100 Hz at the sensory threshold (p < 0.05). There were no significant changes in the other measures. CONCLUSION: The results suggest that EA with an intensity level at the sensorial threshold and 100 Hz frequency increases the corticospinal excitability of M1. This effect may be associated with a decrease in the activity of inhibitory intracortical mechanisms. TRIAL REGISTRATION NUMBER: U1111-1173-1946 (Registro Brasileiro de Ensaios Clínicos; http://www.ensaiosclinicos.gov.br/).

Lower limb auriculotherapy points improves balance in young healthy subjects-assessed by computerized baropodometry.

OBJECTIVE: To analyze the effects of Lower Limb (LL) auricular stimulation points on the static equilibrium of healthy subjects, assessed by computerized baropodometry. METHODS AND MATERIALS: Forty volunteers were assigned to one of two groups: Auriculotherapy (AT) who received unilateral needle stimulation of the coxofemoral, knee, and ankle points. Control (C) who did not receive any stimulation. We analyzed the contact area (CA) and the peak pressure (PP) for both feet at baseline, 20 and 25 min after the baseline was recorded. Three-Way ANOVA (P < 0.05) was used for data analysis. RESULTS: AT showed an increase in CA (F:6.49) and a decrease in PP (F:3.11) at 20 and 25 min, when compared to C. The PP decreased was only for the right LL at 20 and 25 min (F:6.45). CONCLUSION: The auriculotherapy points were able to modify the ipsilateral weight discharge on the same side of the stimulated auricular pavilion.

Opioidergic effects of transcutaneous electrical nerve stimulation on pain and inflammatory edema in a rat model of ankle sprain / Efeitos de opioidérgico da estimulação elétrica nervosa transcutânea sobre a dor e edema inflamatório em um modelo de entorse de tornozelo em ratos / Efectos opioidergicos de la estimulación nerviosa eléctrica transcutánea sobre el dolor y el edema inflamatorio en un modelo de rata con esguince de tobillo

ABSTRACT Although transcutaneous electrical nerve stimulation (TENS) has been proposed to modulate pain and the mechanisms underlying analgesia remain poorly understood, evidence of anti-inflammatory effect is more limited. The purpose of this study was to examine the opioidergic mechanisms of TENS effects in two different frequencies on pain and inflammatory edema in the ankle sprain model in rats. Threshold to mechanical stimulation was utilized to examine the changes produced by intraperitoneal injection of non-selective opioid antagonist naloxone on the antihyperalgesic effect induced by a 20-min period of 2Hz or 100Hz TENS in the ankle sprain model, produced by manually overextending the lateral ligaments. Ankle sprain induced a long-lasting reduction in paw withdrawn latency (PWL) after 30 minutes for up to 24 hours in sham TENS (SH-TENS) treated rats. The reduced PWL after the induction of ankle sprain was restored partially at 0,1,2,3 and 6, but not 24 hours, after the termination of 2 Hz-TENS (LF-TENS). In 100Hz (HF-TENS) the reduction in PWL was shorter than LF-TENS and both LF and HF effects were fully blocked in naloxone-treated rats. LF- and HF-TENS treated rats did not reach the elevation of edema and presented a progressive edema reduction for over 24 hours when compared to SH-TENS group. Both effects were reduced by naloxone. TENS-induced antihyperalgesic and anti-edematous effects observed in ankle sprain model were mediated by the endogenous opioid system.

RESUMO Embora estimulação elétrica nervosa transcutânea (TENS) tem sido proposta para modular a dor e os mecanismos subjacentes a analgesia permanecem mal compreendidos, evidências do efeito anti-inflamatório são mais limitadas. O objetivo deste estudo foi examinar os mecanismos opioidérgicos de efeitos de TENS em duas frequências diferentes sobre dor e edema inflamatório no modelo de entorse de tornozelo em ratos. Limiar de estimulação mecânica foi utilizado para examinar as alterações produzidas pela injeção intraperitoneal de naloxona, um antagonista opioide não-seletivo, sobre o efeito anti-hiperalgésico induzido por um período de 20 min de 2Hz ou 100Hz de TENS no modelo de entorse de tornozelo, produzido ultrapassando manualmente os ligamentos laterais. Entorse de tornozelo induziu uma redução duradoura na latência de retirada da pata (PWL) depois de 30 minutos até 24 horas em ratos tratados para TENS "simulada" (SH-TENS). A PWL reduzida após a indução de entorse de tornozelo foi restaurada parcialmente em 0,1,2,3 e 6, mas não em 24 horas, após o término do 2 Hz-TENS (LF-TENS). Em 100Hz (HF-TENS) a redução de PWL foi menor do que LF-TENS e tanto os efeitos HF e LF foram totalmente bloqueados em ratos tratados com naloxona. Ratos tratados com LF- e HF-TENS não alcançou a elevação do edema e apresentaram uma redução progressiva do edema por mais de 24 horas, quando comparado ao grupo SH-TENS. Ambos os efeitos foram reduzidos pela naloxona. Efeitos anti-hiperalgésicos induzidos por TENS e efeitos antiedematosos observados no modelo de entorse de tornozelo foram mediados pelo sistema de opioides endógenos.

RESUMEN Aunque la estimulación nerviosa eléctrica transcutánea (TENS) ha sido propuesta para modular el dolor y los mecanismos subyacentes a la analgesia sigue siendo mal entendida, la evidencia del efecto antiinflamatorio es limitada. El propósito de este estudio fue examinar los mecanismos opioidérgicos de los efectos de la TENS en dos frecuencias diferentes sobre el dolor y el edema inflamatorio en un modelo de ratas con esguince de tobillo. Se utilizó el umbral a la estimulación mecánica para examinar los cambios producidos por inyección intraperitoneal del antagonista opiáceo no selectivo naloxona sobre el efecto antihiperalgésico inducido por un período de 20 minutos de 2Hz o 100Hz TENS en el modelo con esguince de tobillo, producido por sobrecarga manual de los ligamentos laterales. El esguince de tobillo indujo una reducción de larga duración en latencia de la pata retraída (PWL) después de 30 minutos por hasta 24 horas en simulación de la TENS (SH-TENS) para las ratas tratadas. El PWL reducido después de la inducción del esguince de tobillo fue restaurado parcialmente en 0,1,2,3 y 6, pero no por 24 horas, después de la terminación de 2 Hz-TENS (LF-TENS). La reducción en PWL fue menor que LF-TENS en 100Hz (HF-TENS) y tanto los efectos de LF como de HF fueron completamente bloqueados en ratas tratadas con naloxona. Las ratas tratadas con LF- y HF-TENS no alcanzaron la elevación del edema y presentaron una reducción progresiva del edema durante más de 24 horas en comparación con el grupo SH-TENS. Ambos efectos fueron reducidos por la naloxona. Efectos antihiperalgésicos y antiedematosos TENS-inducidos observados en el modelo con esguince de tobillo fueron mediados por el sistema opioide endógeno.

100-Hz Electroacupuncture but not 2-Hz Electroacupuncture is Preemptive Against Postincision Pain in Rats.

Preemptive analgesia involves introducing an analgesic before noxious stimulation. Electroacupuncture (EA) activates descending mechanisms that modulate nociceptive inputs into the spinal dorsal horn. This study evaluated whether preoperative EA is more effective than postoperative EA in reducing incision pain in rats. The nociceptive threshold to mechanical stimulation was utilized to examine the effects of an intraperitoneal injection of saline (0.1 mL/kg) or naloxone (1 mg/kg) on antinociception induced by a 20-minute period of 2-Hz or 100-Hz EA applied to the Zusanli (ST36) and Sanyinjiao (SP6) acupoints before surgical incision, or 10 minutes after or 100 minutes after surgical incision of the hind paw. The extent of mechanical hyperalgesia after the incision was significantly attenuated by the application of 100-Hz EA preoperatively, but not by its application at 10 minutes or 100 minutes postoperatively. By contrast, 2-Hz EA was effective against postoperative hyperalgesia when applied 10 minutes or 100 minutes after surgery but not when it was applied preoperatively. Only the effect of 2-Hz EA applied 10 minutes after surgery was sensitive to naloxone. The present study showed for the first time that 100-Hz EA, but not 2-Hz EA, exerts a nonopioidergic preemptive effect against postincision pain in rats.

Efeitos do resfriamento e aquecimento articular no desempenho funcional do ombro / Effects of cooling and heating on shoulder functional performance / Efectos del enfriamiento y del calentamiento articular del hombro en el desempeño funcional

INTRODUÇÃO: Um dos recursos mais utilizados na reabilitação de lesões musculoesqueléticas é a termoterapia por subtração de calor (crioterapia), enquanto a termoterapia por adição de calor é considerada o procedimento mais antigo de reabilitação física. Entretanto, há poucas evidências que tenham investigado os efeitos desses recursos sobre o desempenho de membros superiores. OBJETIVO: Comparar o efeito do resfriamento e do aquecimento articular sobre o desempenho funcional do membro superior. MÉTODOS: Trinta e quatro voluntários (22,23 ± 2,17 anos; 22,39 ± 2,53 kg/m2), de ambos os sexos, foram divididos aleatoriamente em um dos três grupos: 1) grupo crioterapia GCR (n=10): submetidos ao resfriamento articular por compressas frias; 2) grupo termoterapia - GTE (n=10): submetidos ao aquecimento articular por ondas curtas e 3) grupo controle - GCO (n=14), não submetidos a qualquer intervenção. Os voluntários foram avaliados, pré e pós-intervenção, quanto ao desempenho funcional de membros superiores por meio dos testes de estabilidade da extremidade superior em cadeia cinética fechada (TEESCCF) e das condições de equilíbrio em apoio bimanual sobre o baropodômetro. Ainda, os voluntários foram avaliados quanto ao desempenho funcional virtual por meio do jogo Mario Kart (Nintendo Wii (r) ). RESULTADOS: Houve melhora significativa nos valores pós-intervenção no TEESCCF para o GCR (p<0,001), GTE (p=0,002) e GCO (p=0,01). Não houve alteração significativa na área de deslocamento do centro de pressão na condição de olhos abertos, nos três grupos (p>0,05). Entretanto, na condição de olhos fechados, houve piora de desempenho para GTE (p=0,04) e melhora de desempenho para o GCO (p=0,02). Não houve alteração significativa no desempenho funcional virtual para os três grupos (p>0,05). CONCLUSÃO: Embora não tenha favorecido o desempenho funcional em todos os testes reais e virtuais utilizados, o resfriamento articular foi mais efetivo que o ...

INTRODUCTION: Thermotherapy by heat subtraction or cryotherapy is one of the most used resources in the physical rehabilitation whereas thermotherapy by addition of heat is considered as the oldest procedure in physical rehabilitation. However, there are few evidences regarding the effects of these physical agents on the performance of upper limbs. OBJECTIVE: To compare the effect of joint cooling and joint heating on functional performance of the upper limb. METHODS: Thirty-four subjects (22.23 ± 2.17 years old; 22.39 ± 2.53 kg/m2) of both genders were randomly assigned to one of the following three groups: 1) subjects who were submitted to joint cooling with cold compresses - CRG (n=10); 2) subjects who were submitted to joint heating by shortwave thermotherapy - THG (n=10) and 3) subjects who were not submitted to any intervention - control group - COG (n=14). Upper limb performance was assessed pre- and post-intervention by the closed kinetic chain upper extremity stability test (CKCUEST). Balance conditions were assessed in upper limb supporting on a pressure platform. Virtual performance was evaluated by Mario Kart Wii game (Nintendo Wii(r)). RESULTS: There was significant improvement in post intervention measurements in CKCUEST for both CRG (p<0.001), THG (p=0.002) and COG (p=0.01). There were no significant changes in the center of pressure area displacement with opened eyes in the three groups (p> 0.05). However, in the closed eyes condition, there was a worsened performance for THG (p=0.04) and improved performance for COG (p=0.02). No significant changes in virtual performance were observed for the three groups (p>0.05). CONCLUSION: Joint cooling was more effective than joint heating to maintain the upper limb muscle performance, especially in upper limb balance with closed eyes although it did not favor functional performance in all real and virtual tests. .

INTRODUCCIÓN: Uno de los recursos más utilizados en la rehabilitación de lesiones musculoesqueléticas es la termoterapia por sustracción de calor (crioterapia), mientras que la termoterapia por agregado de calor es considerada como el procedimiento más antiguo de la rehabilitación física. Entretanto, hay pocas evidencias de que se hayan investigado los efectos de esos recursos sobre el desempeño de miembros superiores. OBJETIVO: Comparar el efecto del enfriamiento y del calentamiento articular sobre el desempeño funcional del miembro superior. MÉTODOS: Treinta y cuatro voluntarios (22,23 ± 2,17 años; 22,39 ± 2,53 kg/m2), de ambos sexos, fueron divididos randómicamente a uno de los tres grupos: 1) grupo crioterapia GCR (n = 10) sometidos al enfriamiento articular por compresas frías; 2) grupo termoterapia - GTE (n = 10) sometidos al calentamiento articular por ondas cortas y 3) grupo control - GCO (n = 14), no sometidos a ninguna intervención. Los voluntarios fueron evaluados antes y después de la intervención, cuanto al desempeño funcional de los miembros superiores a través de los tests de estabilidad de la extremidad superior en cadena cinética cerrada (TEESCCF) y de las condiciones de equilibrio en apoyo bimanual en un baropodómetro. Además, los voluntarios fueron evaluados cuanto al desempeño funcional virtual a través del juego Mario Kart (Nintendo Wii(r)). RESULTADOS: Hubo mejora significativa en los valores post-intervención en TEESCCF para GCR (p <0,001), GTE (p = 0,002) y GCO (p = 0,01). No hubo alteración significativa en el área de desplazamiento del centro de presión en la condición de ojos abiertos, en los tres grupos (p> 0,05). Entretanto, en la condición de ojos cerrados, empeoró el desempeño de GTE (p = 0,04) y mejora en el desempeño funcional para el GCO (p = 0,02). No hubo alteración significativa en el desempeño funcional virtual para los tres grupos (p> 0,05). CONCLUSIÓN: A pesar de que no se haya favorecido ...

Electroacupuncture at 2/100 hz activates antinociceptive spinal mechanisms different from those activated by electroacupuncture at 2 and 100 hz in responder rats.

We examined the effects of intrathecal injection of desipramine and fluoxetine (selective inhibitors of norepinephrine and 5-HT uptake, resp.), thiorphan and neostigmine (inhibitors of enkephalinase and acetylcholinesterase, resp.), gabapentin (a GABA releaser), and vigabatrin (an inhibitor of GABA-transaminase) on the antinociception induced by 2 Hz, 100 Hz, or 2/100 Hz electroacupuncture (EA) applied bilaterally to the Zusanli (ST36) and Sanyinjiao (SP6) acupoints using the rat tail-flick test. We show that 2 Hz EA antinociception lasts longer after the administration of drugs that increase the spinal availability of norepinephrine, acetylcholine, or GABA; 100 Hz EA antinociception lasts longer after drug that increases the spinal availability of norepinephrine; 2/100 Hz EA antinociception lasts longer after drugs that increase the spinal availability of endogenous opioids or GABA. We conclude that the antinociceptive effect of 2/100 Hz EA is different from the synergistic effect of alternate stimulation at 2 and 100 Hz because the effect of the former is not changed by increasing the spinal availability of serotonin and lasts longer after the administration of vigabatrin. The combination of EA with drugs that increase the availability of spinal neurotransmitters involved in the modulation of nociceptive inputs may result in a synergistic antinociceptive effect in the rat tail-flick test.

Effect of acupuncture at tender points for the management of fibromyalgia syndrome: a case series.

BACKGROUND: Affecting more women than men, fibromyalgia syndrome (FMS) is a rheumatic disorder characterized by chronic, diffuse and widespread musculoskeletal pain, and its pathogenesis is still unknown. Among the recommended treatments, acupuncture (for its analgesic effects) is an effective option for reducing the pain sensitivity and improving quality of life. Therefore, this study aimed to investigate whether acupuncture at tender points could effectively manage FMS. METHODS: Eight female patients, with a previous diagnosis of fibromyalgia, underwent an initial assessment involving pressure algometer measurements for pain tolerance and questionnaires [Fibromyalgia Impact Questionnaire (FIQ), Heath Assessment Questionnaire (HAQ), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI)], followed by treatment. Over a 2-month period, acupuncture was performed once per week at five tender points, located bilaterally at the occipital bone, trapezius, rhomboid, upper chest and lateral epicondyle. At the end of treatment, the participants underwent a reassessment for a final review of the applied methods. RESULTS: We observed a reduction in the pain threshold and sensitivity and improvement in the areas of anxiety and depression and quality of life, which were demonstrated using the FIQ, BDI and BAI but not the HAQ. CONCLUSION: The results demonstrated the effectiveness of tender-point acupuncture treatment on the patients' overall well-being, not only by improving quality of life, but also by reducing the pain sensitivity of FMS.

The combined effect of acupuncture and Tanacetum parthenium on quality of life in women with headache: randomised study.

BACKGROUND: The aim of the present study was to investigate the efficacy and tolerability of acupuncture (AC), Tanacetum (TAN) or combined treatment on quality of life in women with chronic migraine (CM). METHODS: A total of 69 women volunteers were randomly divided into 3 groups: AC, acupuncture administered in 20 sessions over 10 weeks (n=22); TAN, at 150 mg/day (n=23); and AC+TAN (n=23). The primary outcome was Short-Form 36 (SF-36) quality of life assessment score. Secondary outcomes included the Migraine Disability Assessment (MIDAS) and visual analogue scale (VAS) score experienced after randomisation. RESULTS: AC+TAN was statistically significantly more effective than AC or TAN alone in overall health-related quality of life (SF-36; p<0.05), on MIDAS score (-35.1 (10.6) AC vs -24.8 (11.7) TAN vs -42.5 (9.8) AC+TAN; p<0.05) and in reducing the mean score of pain on VAS (-5.6 (2.4) AC vs -3.7 (2.1) TAN vs -6.4 (3.1) AC+TAN; p<0.05). CONCLUSIONS: The present work shows an improvement of the quality of life and better analgesic effect of acupuncture combined with TAN treatment on migraine pain in women when compared with acupuncture or TAN alone.