• The Korean Journal of Pain
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• v.22 no.1
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• pp.21-27
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• 2009

Background: The neuropathic pain arising from nerve injury is difficult to treat and the therapeutic effects of opioid drugs remain debatable. Agonists acting at the ${\alpha}_2$ adrenergic and opioid receptors have analgesic properties and they act synergistically when co-administered in the spinal cord. The lack of subtype-selective pharmacological agents has previously impeded the synergistic effects that are mediated by the adrenergic receptor subtypes. Methods: We created neuropathic pain model by ligating the L5 spinal nerve in Sprague-Dawley rats (n = 18). We divided the rats into three groups (n = 6 for each group), and we administered intraperitoneal morphine (1 mg/kg, 3 mg/kg, 5 mg/kg) and then we measured the mechanical allodynia with using von-Frey filaments for 8 hours. We then injected morphine (5 mg/kg) intraperitoneally, twice a day for 2 weeks. We measured the tactile and cold allodynia in the morphine group (n = 9) and the saline group (n = 9). After 2 weeks, we decapitated the rats and harvested the spinal cords at the level of lumbar enlargement. We compared the ${\alpha}_2$ subtype mRNA expression with that of control group (n = 6) by performing real time polymerase chain reaction (RTPCR). Results: Intraperitoneal morphine reduced the neuropathic pain behavior in the dose-dependent manner. Chronic morphine administration showed an antiallodynic effect on the neuropathic pain rat model. The rats did not display tolerance or hyperalgesia. The expression of the mRNAs of the ${\alpha}_{2A}$, ${\alpha}_{2B}$, ${\alpha}_{2C}$ subtypes decreased, and morphine attenuated this effect. But we could not get statistically proven results. Conclusions: Systemic administration of morphine can attenuate allodynia during both the short-term and long-term time course. Morphine has an influence on the expression of ${\alpha}_2$ receptor subtype mRNA. Yet we need more research to determine the precise effect of morphine on the ${\alpha}_2$ subtype gene expression.

• Journal of Pharmacopuncture
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• v.4 no.1
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• pp.65-84
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• 2001

We recently demonstrated that bee venom (BV) injection into acupoint (i.e. Zusanli) produced more potent anti-inflammatory and antinociciptive effect in Freunds adjuvant induced rheumatoid arthritis (RA) model as compared with that of non-acupoint injection(i.e back). However, the precise components underlying BV-induced antinociceptive and/or anti-inflammatory effects have not been fully understood. Therefore, we further investigated the anti-arthritic effect of BV after extracting the whole BV according to solubility (water soluble: BVA, ethylacetate soluble: BVE). Subcutaneous BVA treatment (0.9 mg/kg/day) into Zusanli acupoint was found to dramatically inhibit paw edema and radiological change (i.e. new bone proliferation and soft tissue swelling) caused by Freunds adjuvant injection. In addition, the increase of serum interleukin-6 by RA induction was normalized by the BVA treatment as similar with that of non-arthritic animals. On the other hand, BVA therapy significantly reduced arthritis induced nociceptive behaviors (i.e., nociceptive score for mechanical hyperalgesia and thermal hyperalgesia). Furthermore, BVA treatment significantly suppressed adjuvant induced Fos expression in the lumbar spinal cord at 3 weeks post-adjuvant injection. However, BVE treatment (0.05 mg/kg/day) has not any anti-inflammatory and anti-nociceptive effect on RA. Based on the present results, we demonstrated that BVA might be a effective fraction in whole BV for long-term treatment of RA-induced pain and inflammation. However, it is clear necessary that further fraction study about BVA was required for elucidating an effective component of BVA.

• Journal of Acupuncture Research
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• v.20 no.3
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• pp.117-130
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• 2003

To study the analgesic and effect and its mechanism of eletroacupunture(EA) on the chronic inflammatory pain 50 rats were induced with arthralgesia by injecting complete freund's adjuvant(CFA). Two weeks after the injection of CFA, EA stimulation(2Hz, 0.07mA, 0.3ms) was delivered to Jogsamni($ST_{36}$) for 20 minutes. Analgesic effect was evaluated by using the tail flick latency(TFL) and the analgesic mechanism was observed by applying TFL with the pretreatment with naloxone and yohimbine. The results were as follows ; 1. TFL level for the model of adjuvant-induced arthritis decreased as time went by and it induced the hyperalgesia. 2. EA stimulation delivered to Jogsamni($ST_{36}$) for 20 minutes in the rat model of adjuvant-induced arthritis brought analgesic effect and its effect had lasted for 40 minutes after the stimulation. 3. The analgesic effect of Jogsamni($ST_{36}$) EA in the rat model of adjuvant-induced arthritis was blocked by pretreatment with naloxone(2mg/kg,i.p). This result suggests that the EA effect on the chronic inflammatory pain can be related to the endogenous opioid mechanism. 4. The analgesic effect of Jogsamni($ST_{36}$) EA in the rat model of adjuvant-induced arthritis was blocked by pretreatment with naloxone(2mg/kg,i.p). This result suggests that the EA effect on the chronic inflammatory pain can be related to the ${\alpha}_2$-adrenergic mechanism.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.65-74
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• 2017

Here we investigated the central processing mechanisms of mechanical allodynia and found a direct excitatory link with low-threshold input to nociceptive neurons. Experiments were performed on male Sprague-Dawley rats weighing 230-280 g. Subcutaneous injection of interleukin 1 beta ($IL-1{\beta}$) ($1ng/10{\mu}L$) was used to produce mechanical allodynia and thermal hyperalgesia. Intracisternal administration of bicuculline, a gamma aminobutyric acid A ($GABA_A$) receptor antagonist, produced mechanical allodynia in the orofacial area under normal conditions. However, intracisternal administration of bicuculline (50 ng) produced a paradoxical anti-allodynic effect under inflammatory pain conditions. Pretreatment with resiniferatoxin (RTX), which depletes capsaicin receptor protein in primary afferent fibers, did not alter the paradoxical anti-allodynic effects produced by the intracisternal injection of bicuculline. Intracisternal injection of bumetanide, an Na-K-Cl cotransporter (NKCC 1) inhibitor, reversed the $IL-1{\beta}$-induced mechanical allodynia. In the control group, application of GABA ($100{\mu}M$) or muscimol ($3{\mu}M$) led to membrane hyperpolarization in gramicidin perforated current clamp mode. However, in some neurons, application of GABA or muscimol led to membrane depolarization in the $IL-1{\beta}$-treated rats. These results suggest that some large myelinated $A{\beta}$ fibers gain access to the nociceptive system and elicit pain sensation via $GABA_A$ receptors under inflammatory pain conditions.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.99-119
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• 2006

Endothelin (ET) is a 21 amino acid peptide with multifunctional effects on the vasculature as well as a variety of other cell types such as respiratory, gastrointestinal, urogenital, endocrine, central nervous systems, and others. Endothelin has emerged as a modulator by autocrine and paracrine actions for many cellular activities, including vasoconstriction, cell proliferation, hormone production, neurotransmitter and/or neuromodulator. The endothelin family consists of three closely related peptides, ET-1, ET-2, and ET-3 derived from separate genes, such as chromosome 6, 1, and 20, respectively. ET-1 is the predominant isoform produced in the cardiovascular system and about which most is known. Endothelin receptors are seven-transmembrane GTP-binding protein-coupled receptors, which are classified into endothelin-A (ETA) and endothelin-B (ETB) receptors. Interestingly, recent evidence is accumulating to suggest that ET -1 may contribute to a variety of pain states such as allodynia and hyperalgesia in animals and humans. Therefore, in this review the biological characteristics and contraction-related mechanism of endothelin-1 in mammalian cells will be summarized. Especially, we focus on multifunctional roles for ET-1 in noxious stimulation-induced pain for the study of pain specialized physical therapy.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.299-304
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• 2005

This study examined the antinociceptive properties of GCSB-5, a herbal formulation consisting of 6 Oriental herbs (Ledebouriellae Radix, Achyranthis Radix, Acanthopanacis Cortex, Cibotii Rhizoma, Glycine Semen, and Eucommiae Cortex) that are used in traditional medicine to treat various bone disorders, mainly of which involve analgesic processes. Peripheral and central analgesic models were established in experimental animals in order to evaluate the antinociceptive effects of the agent. GCSB-5 significantly inhibited the number of acetic-induced writhing (33.3%-34.3% inhibition at 100-600 mg/kg) but increased the pain threshold (38.0% increase at 300 mg/kg) in the Randall-Selitto test. However, GCSB-5 had no effect on the hot plate-induced nociception and hyperalgesia from the tail-pinch method. These results suggest that the antinociceptive effect of GCSB-5 may be mediated via peripheral mechanisms.

• Journal of Acupuncture Research
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• v.23 no.4
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• pp.149-162
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• 2006

Objectives : The aim of this study is to evaluate the analgesic effect of electroacupuncture on Jogsamni (ST36) in the collagen-induced arthritis rats and investigate the role played by opioid receptor subtypes $({\mu},\;{\delta},\;{\kappa})$ in the antinociceptive effect of electroacupuncture (EA) In the thermal hyper algesia test. Methods : Immunization of male Sprague-Dawley rats with bovine type H collagen emulsified in incomplete Freund's adjuvant, followed by booster injection 2 weeks later induced collagen-induced arthritis (CIA). The thermal hyperalgesia was evaluated weekly with tail flick latency (TFL). In the fourth week after first immunization, EA stimulation (2 Hz, 0.07 mA, 0.3 ms) was delivered into Jogsamni (5736) for 20 minutes. Analgesic effect was evaluated by using the tail flick latency (TFL) after intraperitoneal injection of normal saline, naloxone, naltrindole and nor-binaltorphimine respectively to CIA rats. Results : The results were as follows; 1. The TFL were gradually decreased in CIA as time elapsed after e immunization of arthrogenic collagen and the maximum value was reached between the third to fifth week. 2. EA stimulation on 5736 inhibited chronic inflammatory pain induced by CIA. 3. The analgesic effect of EA was inhibited by pretreatment of ${\mu}-receptor$ antagonist (naloxone),${\delta}-receptor$ antagonist (naltrindole) and ${\kappa}-receptor$ antagonist (nor-binaltorphimine) respectively. Conclusion : Electroacupuncture has an analgesic effect on the CIA rat and has an antinociception mediated by 8, 5, H receptors.

• Korean Journal of Acupuncture
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• v.33 no.3
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• pp.95-101
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• 2016

Objectives : This study aims to overview the therapeutic mechanism of back-shu points in terms of sympathetic visceral motor nervous system. Methods : Studies about autonomic nervous system, and studies and ancient texts about back-shu points were reviewed. We interpreted possible mechanism of back-shu points considering similarities of anatomical and physiological characteristics of back-shu points and visceral motor nervous system. Results : Afferent signals for organ lesions that can develop the symptoms of autonomic neurological symptoms, pain, hyperalgesia through the skin segment. Through a physical examination of the myotome and dermatome, it is possible to diagnose segmental disorders. Treatment stimulation of the thick fibers of the disorder segment skin can reduce abnormal autonomic influence over the sympathetic reflex mechanism. In addition, if spinal muscles are relaxed, the pressure on the nerve roots could be reduced and consequently the hyperactivity of the sympathetic visceral motor signal would be suppressed. Conclusions : The back-shu points treatments work through the mechanism of the sympathetic nervous reflex. Moreover, segmental acupuncture can reduce tension of the spinal muscles, thereby improving pathological conditions of the sympathetic nervous system.

• International Journal of Oral Biology
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• v.39 no.1
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• pp.49-56
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• 2014

We investigated the role of central P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out using male Sprague-Dawley rats weighing 230-280g. Complete Freund's adjuvant (CFA, $40{\mu}L$) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. The intracisternal administration of iso-PPADS tetrasodium salt, a non-selective P2X receptor antagonist, A317491 sodium salt hydrate, a $P2X_{2/3}$ receptor antagonist, 5-BDBD, a $P2X_4$ receptor antagonist, or A438079 hydrochloride, a $P2X_7$ receptor antagonist, was performed 5 days after CFA injection. Subcutaneous injections of CFA produced increases in thermal hypersensitivity. Intracisternal injections of iso-PPADS ($25{\mu}g$) or A438079 (25 or $50{\mu}g$) produced significant anti-hyperalgesic effects against thermal stimuli compared to the vehicle group. A317491 or 5-BDBD did not affect the head withdrawal latency times in rats showing an inflammatory response. Subcutaneous injections of CFA resulted in the up-regulation of OX-42, a microglia marker, and GFAP, an astrocyte marker, in the medullary dorsal horn. The intracisternal administration of A438079 reduced the numbers of activated microglia and astrocytes in the medullary dorsal horn. These results suggest that a blockade of the central $P2X_7$ receptor produces antinociceptive effects, mediated by inhibition of glial cell function in the medullary dorsal horn. These data also indicate that central $P2X_7$ receptors are potential targets for future therapeutic approaches to inflammatory pain in the orofacial area.

• Journal of Acupuncture Research
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• v.22 no.1
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• pp.77-90
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• 2005

Objective : Neuropathic pain sometimes arises from a partial peripheral nerve injury. This kind of pain is usually accompanied by spontaneous burning pain, allodynia and hyperalgesia. It has been well known that acupuncture is effective to the pain control from ancient time in Asia. However, it is not clear whether Electroacupuncture(EA) & Acupuncture(AC) can control neuropathic pain effectively. The aim of this study is to examine if Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL4O), Hu-gye(SI03) Wijung(BL40) may be effective to the neuropathic pain (mechanical allodynia cold allodynia) in a rat model of neuropathic pain. Methods : A rat model of neuropathic pain was made by injurying tibial nerve and sural nerve while common peroneal nerve was maintained. After the neuropathic surgery, we examined if the rats exhibited the behavioral signs allodynia. The allodynia was assessed by stimulating the medial malleolus with von frey filament and acetone. Three weeks after the neuropathic surgery, electroacupuncture &, acupuncture stimulation was delivered to Hu-gye(SI03), Wijung(BL40), Hu-gye(SI03) Wijung(BL40) one time a day for one week. After that we examined the withdrawal response of neuropathic rats' legs by von frey filament and acetone stimulation, c-fos and AchE(Acetylcholine esterase) in the periaqe- ductal gray(PAG) of neuropathic rats' brain. Results : 1. Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye(SI03) Wijung(BL4O) significantly decreased the withdrawal response of mechanically allodynia in EA-BL40+SI03 group and AC-SI03 group as compared with control group on 6th day. 2. Electroacupuncture &Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye (SI03) Wijung (BL40) significantly decreased the withdrawal response of chemical allodynia(cold allodynia) in EA-SI03 group, EA-BL40+SI03 group and AC-SI03 group as compared with control group on 6th day. 3. Electroacupuncture & Acupuncture at Hu-gye ( SI03), Wijung (BL40), Hu-gye (SI03) Wijung(BL40) significantly decreased the expression of c-fos in the periaqe- ductal gray(PAC) of neuropathic rats' brain in EA-BL40+SI03 group and AC-SI03 group as compared with control group. 4. Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye (SI03) Wijung(BL40) significantly decreased the expression of AchE in the periaqe- ductal gray(PAG) of neuropathic rats' brain in EA-BL40+SI03 group and AC-SI03 group as compared with control group. Conclusions : Based on the above results it is assumed that Electroacupuncture at Hu-gye(SI03) Wijung(BL40) and Acupuncture at Hu-gye(SI03) can help the treatment of neuropathic pain.