• Korean Journal of Acupuncture
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• v.36 no.4
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• pp.264-273
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• 2019

Objectives : Microglia play a crucial role in electroacupuncture (EA) analgesia on neuropathic pain. The role of chemokines in producing analgesic effects of EA, however, is largely unknown. In the present study, we investigated the role of chemokines in producing analgesic effects of EA in the neuropathic pain model. Methods : Sprague-Dawley rats were randomly assigned into three groups (anesthetized group (ANE), non-acupoint EA group (NAP), and ST36 - GB34 EA group (ACU)). Neuropathic pain was induced by tight ligation of L5 spinal nerve. Mechanical and thermal hypersensitivity of hind paw was tested. Western blot tests and immunofluorescence assay for C-C motif chemokine ligand 2 (CCL2) levels and microglia activation were performed on spinal cord L5/6. EA was treated once daily from the 3rd day after surgery for 5 days. Results : EA treatments applied to ST36 and GB34 significantly reduced both mechanical and thermal hypersensitivity after two and three times of treatment, respectively. While CCL2 expression significantly increased in neuropathic rats, it was significantly reduced in the ACU. In addition, co-localization of CCL2 and activated microglia significantly decreased in the ACU compared to those of ANE and NAP in the spinal cord L5/L6 dorsal horn. Conclusions : The present results suggest that EA applied to ST36 and GB34 modulates the reduction of CCL2 release from the injured neurons and consequently decreases microglia activation in the spinal cord. Regulation of chemokine induced spinal activation of microglia plays a key role in analgesic effects of EA in the rat model of neuropathic pain.

• Korean Journal of Acupuncture
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• v.30 no.1
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• pp.47-55
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• 2013

Objectives : The purpose of this study was to determine whether electroacupuncture(EA) is effective in reducing pain on the severe ankle sprain classified as grade 3 in rats. Methods : The severe(grade 3) ankle sprain model was induced surgically by ankle ligament injury(the anterior talofibular, the calcaneofibular and the posterior talofibular) in the Sprague-Dawley rats(180~250 g). The effects of EA on weight bearing forces(WBR) of the affected foot were examined in a rat model of ankle sprain. EA was applied to either SI6, ST37, GB34, GB39 or GB42 acupoints by trains of electrical pulses(2 Hz, 1 ms pulse width, 2 mA intensity) for 15 min. Results : Cutting of the lateral ankle ligament complex produced the severe ankle sprain symptoms as grade 3. EA of the contralateral SI6 resulted in more analgesic effect than one of ipsilateral SI6 even though there was significant effect. EA of the ipsilateral GB34 and GB39 produced potent analgesic effects on the surgical ankle sprained pain behaviors. However, there were no significant analgesic effects in the contralateral GB34 and GB39 EA groups. In addition, both side of ST37 and GB42 did not result in analgesic effect on the surgical ankle sprained rat. Conclusions : The data suggest that EA induced analgesia shows point specificity on the severe ankle sprained pain model classified as grade 3.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.568-573
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• 2009

The purpose of this study is to evaluate the analgesic effects on the oral cavity in dogs which are treated with xylazine and electroacupuncture (EA). Furthermore, this study aims to find out its effects on glucose (GLU), serum alanine aminotransferase (ALT), and blood urea nitrogen (BUN) variation values, vital signs (rectal temperature, heart rate, respiratory rate) and pain responses to the noxious stimuli. Eight healthy dogs were randomly assigned to receive either xylazine or EA. Xylazine group dogs with weight of 3.6${\pm}$1.0 kg received 1.5 mg/kg of xylazine intramuscularly. EA group dogs with weight of 3.9${\pm}$1.0 kg received 1 volt (10-15 hz) for 5 minutes, and then 1-9 Volts (25-30 hz) for 60 minutes totally. The acupoints used were LI-3 (San Jian), LI-4 (He Gu) and ST-7 (Xia Guan). All dogs were examined before and 10, 25, 40, 55 and 120 minutes after administration of xylazine or EA. The mean rectal temperatures of the EA group were significantly higher than those of xylazine group after 25, 40 and 55 minutes (p < 0.05). The mean heart rates of the EA group were significantly higher than those of xylazine group after 10, 25, 40 and 55 minutes (p < 0.05). The mean respiratory rates of the EA group were significantly higher than those of xylazine group after 55 and 120 minutes (p < 0.05). The mean GLU concentration of the EA group were significantly lower than those of xylazine group after 55 and 120 minutes (p < 0.05). The sum of mean pain scores (SMPS) of the EA group were significantly higher than those of xylazine group after 10, 25 40 and 55 minutes (p < 0.05). In this study, the pain control of the EA group was shown to be better than that of the xylazine group. Also, there do not appear to be any negative physiologic effects associated with acupuncture-induced surgical analgesia. So, it was considered that these acupoints of EA analgesia might be useful for minor oral surgery in weak patients.

• Korean Journal of Acupuncture
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• v.34 no.4
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• pp.265-270
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• 2017

Objectives : The present study aimed to examine the analgesic effect of electroacupuncture(EA) applied to the brook point of the Liver meridian in the rat model of inflammatory pain and to investigate involvement of endogenouse opioid in the EA-induced analgesia. Methods : Knee arthritis was induced by injection of $125{\mu}l$ of complete Freund's adjuvant into the knee joint cavity unilaterally. To examine the level of pain, weight bearing forces(WBFs) of affected limb was measured. EA treatment was given at the LR2, LI4 or non-acupoint on the contralateral limb with frequency of 2 Hz and intensity of 2 mA under gaseous anesthesia. Results : After induction of arthritis, rats subsequently showed a reduced stepping force of the affected hindlimb due to a painful knee. EA applied to the LR2 point on the contralateral hind limb produced a significant improvement of stepping force of the hind limb lasting for at least 2 h, and this effect was equivalent to that obtained by 5 mg/kg of oral indomethacin. The effect of EA was specific to the acupoint since it could not be mimicked by EA applied to the LI4 point or the arbitrary non-acupoint. The analgesic effect was blocked by pretreatment with naltrexone(10 mg/kg, i.p.). Conclusions : These results suggest that acupuncture applied to LR2, brook point of Liver meridian suppresses inflammatory pain in a rat model of knee arthritis and this effect seems to be mediated by endogenous opioid systems.

• The Journal of Korean Medicine
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• v.20 no.3 s.39
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• pp.36-44
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• 1999

Objectives: It has been well known that electroacupuncture(EA) has an analgesic effect and there is a pain control system in the central nervous system(CNS). The pain control system is composed of three major nuclei, which are periaqueductal gray(PAG), raphe nuclei, and the pain inhibitory complex located in the spinal cord. It has been suggested that the analgesic effect of EA might be the result of activation of the pain control system in the CNS. However, there may be a possibility that other nuclei are also involved in this pain modulation. Thus, we investigated whether the posterior intralaminar thalamic nuclei (PTIN) are involved in the pain modulation. Methods: To measure the level of pain, the jaw opening reflex (JOR) was used as a pain index. The magnitude of JOR is estimated by averaging the area of 10 successive responses. JOR was evoked by tooth-pulp stimulation with bipolar electrode carrying stimulus with the following parameters: intensity ranging from 420uA to 680ulA, 0.3ms duration of square pulse, and 0.5 Hz. Hapkog($LI_4$) and Taechung ($LR_3$) were the chosen acupoints. The Hapkog point was stimulated ipsilaterally at 5V, 3 Hz, for 15min in total, and the Taechung was stimulated at 2-3 V, 3 Hz, and for a total of 15 or 30 minutes. Different intensities of stimulation were given the PITN; one was given at $300{\mu}A$ and the other was at 500uA. The position stimulated in these nuclei by Paxinos Atlas was AP; from bregma $-4.0{\sim}-4.3mm,\;L; 0.5{\sim}1.8mm,\;D;\;4.8{\sim}6.3mm$. Results: The Hapkog point had a significant analgesic effect (P<0.05). However, the Taechung point had no effect. Both types of stimulation in the PITN did not reveal any analgesic effects. Conclusions: From these results, it was suggested that the posterior intralaminar thalamic nuclei are not involved in the modulation of pain.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.283-289
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• 2002

The effects of electroacupuncture (EA) at SP-6 with different durations on the minimum alveolar concentration (MAC) and on the cardiovascular system were evaluated in dogs under isoflurane anesthesia. Eight healthy male beagles were randomly assigned to four study groups (n = 5/group) with washout period of 7 days for recovery and anesthetic withdrawal between experiments. Four study groups were control, nonacupoint electrical stimulation (NA), EA for 30 minutes (SP-6) and continuous EA for 70 or 90 minutes (SP-6C). For the nonacupoint electrical stimulation group, needles were inserted into the nonacupoint at the muscle bellies of left triceps brachii and right quadriceps femoris. MAC and cardiovascular parameters were determined after EA at SP-6 acupoint and at nonacupoint. Thirty minutes of EA and continuous EA until re-determination of MAC at SP-6 acupoint lowered the MAC of isoflurane by 21.3$\pm$8.0% and 16.1$\pm$4.6%, respectively (p<0.05). The decrements in MAC values were not significantly different between two EA groups. However, electrical stimulation of nonacupoint did not induce a significant change in MAC. In SP-6 and SP-6C groups, significant changes in cardiovascular parameters were not observed. These results indicate that EA at SP-6 have an advantage in isoflurane anesthesia in terms of reducing the requirement for anesthetics and minimizing cardiovascular side effects. EA for 30 minutes at maximum might be the sufficient time to produce acupuncture analgesia.

• The Journal of Traditional Korean Medicine
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• v.15 no.1
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• pp.113-127
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• 2006

Objectives: This study was produced to examine the effects of moxibustion that had been played important role to traditional oriental medical treatment on disease. Recently, it was reported that moxi-tar which is generated in the process of moxibustion as burning combustibles decreased nitric oxide(NO) and inducible NO synthase (iNOS) generation in cellular experiments. Methods: Carrageenan-induced arthritis rat model was used to test the effect of moxi-tar as a chronic pain model. Diluted moxi-tar was single injected in several acupoints or combined with electroacupuncture (l ms, 2 Hz, and 2 mA) into contralateral ST36 acupoint for 30 min to assess the synergic effects. After the treatment, behavioral tests measuring stepping force were periodically conducted during the next 12 hours. Endogenous NO and iNOS, cyclooxygenase-2 (COX-2), and c-Fos protein expression in the spinal cord were examined on a rat model of carrageenan-induced arthritis. Results : After the induction of arthritis, rats subsequently showed a reduced stepping force of the affected limb for at least the next 4 days. The reduced stepping force of the limb was presumably due to a painful knee, since oral injection of indomethacin produced temporary improvement of weight bearing. Maxi-tar produced significant improvement of stepping force of the hindlimb affected by the arthritis lasting at least 9 hours. The magnitude of this improvement was equivalent to that obtained after an oral injection of 3 mg/kg of indomethacin and this improvement of stepping force was interpreted as an analgesic effect. Maxi-tar produced the improvement of stepping force of the affected hindlimb in a dose-dependent manner. Both NO production and iNOS, COX-2 protein expression increased by arthritis were suppressed by maxi-tar. Moxi-tar on combination with electroacupuncture (EA) produced more powerful and longer lasting improvement of stepping force of the hindlimb affected by the arthritis than either moxi-tar or EA did. Conclusion : The present study suggest that maxi-tar produces a potent analgesic effect on the chronic knee arthritis pain model in the rat and that moxi-tar-induced analgesia modulate endogenous NO through the suppression of iNOS/COX-2 protein expression.