• The Korean Journal of Pain
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• v.33 no.1
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• pp.23-29
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• 2020

Background: Neuropathic pain (NP) is considered a clinically incurable condition despite various treatment options due to its diverse causes and complicated disease mechanisms. Since the early 2000s, multipotent human mesenchymal stem cells (hMSCs) have been used in the treatment of NP in animal models. However, the effects of hMSC injections have not been studied in chronic post-ischemia pain (CPIP) mice models. Here, we investigated whether intrathecal (IT) and intrapaw (IP) injections of hMSCs can reduce mechanical allodynia in CPIP model mice. Methods: Seventeen CPIP C57/BL6 mice were selected and randomized into four groups: IT sham (n = 4), IT stem (n = 5), IP sham (n = 4), and IP stem (n = 4). Mice in the IT sham and IT stem groups received an injection of 5 μL saline and 2 × 10⁴ hMSCs, respectively, while mice in the IP sham and IP stem groups received an injection of 5 μL saline and 2 × 10⁵ hMSCs, respectively. Mechanical allodynia was assessed using von Frey filaments from pre-injection to 30 days post-injection. Glial fibrillary acidic protein (GFAP) expression in the spinal cord and dorsal root ganglia were also evaluated. Results: IT and IP injections of hMSCs improved mechanical allodynia. GFAP expression was decreased on day 25 post-injection compared with the sham group. Injections of hMSCs improved allodynia and GFAP expression was decreased compared with the sham group. Conclusions: These results suggested that hMSCs may be also another treatment modality in NP model by ischemia-reperfusion.

• The Korean Journal of Pain
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• v.27 no.4
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• pp.326-333
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• 2014

Background: Nefopam is a centrally acting non-opioid analgesic agent. Its analgesic properties may be related to the inhibitions of monoamine reuptake and the N-methyl-D-aspartate (NMDA) receptor. The antinociceptive effect of nefopam has been shown in animal models of acute and chronic pain and in humans. However, the effect of nefopam on diabetic neuropathic pain is unclear. Therefore, we investigated the preventive effect of nefopam on diabetic neuropathic pain induced by streptozotocin (STZ) in rats. Methods: Pretreatment with nefopam (30 mg/kg) was performed intraperitoneally 30 min prior to an intraperitoneal injection of STZ (60 mg/kg). Mechanical and cold allodynia were tested before, and 1 to 4 weeks after drug administration. Thermal hyperalgesia was also investigated. In addition, the transient receptor potential ankyrin 1 (TRPA1) and TRP melastatin 8 (TRPM8) expression levels in the dorsal root ganglion (DRG) were evaluated. Results: Pretreatment with nefopam significantly inhibited STZ-induced mechanical and cold allodynia, but not thermal hyperalgesia. The STZ injection increased TRPM8, but not TRPA1, expression levels in DRG neurons. Pretreatment with nefopam decreased STZ-induced TRPM8 expression levels in the DRG. Conclusions: These results demonstrate that a nefopam pretreatment has strong antiallodynic effects on STZ-induced diabetic rats, which may be associated with TRPM8 located in the DRG.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1285-1290
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• 2007

The present study aims to identify and characterize genes that cause differen genes between non-responders and responders to electroacupuncture (EA) on mechanical allodynia following peripheral nerve injury. Under sodium pentobarbital anesthesia, animals were subjected to unilateral transection of the superior caudal trunk at the level between S1 and S2 spinal nerves. EA stimulation (2Hz, 0.3 ms, 0.2-0.3 mA) was delivered to Zusanli (ST36) for 30 min 2 weeks after the surgery. The degree of mechanical allodynia was assessed quantitatively by touching the tail with von Frey hair (2.0 g) at 10 min intervals. The rats, which showed an EA-induced decrease of response frequencies under 10 %, were classified as non-responders and those displaying an EA-induced decrease of response frequencies 20 % or more were classified as responders. Results from oligonucleotide microarray, to which cDNAs from the spinal dorsal horn (DH) were applied, showed that hemoglobin beta chain complex and chondroitin sulfate proteoglycan-5 decreased and limbic system-associated membrane protein increased in the non-responder group, whereas calcium-independent alpha-Iatrotoxin receptor homolog-3 increased in the responder group. These results suggest that The functional abnormality of molecules regulating cell adhesion, intracellular signal transduction and cell differentiation in the spinal DH may be involved in the anti-allodynic effect of EA.

• Korean Journal of Acupuncture
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• v.36 no.1
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• pp.52-62
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• 2019

Objectives : The objective of this study was to investigate the effects of Zingiberis Rhizoma Pharmacopuncture(ZP) at GB30 and ST36 in neuropathic pain induced SD rats by the block of Transient Receptor Potential Vanilloid 1(TRPV1). Methods : Neuropathic pain in rats was induced by tibial and common peroneal nerve transection of right leg. The rat subjects were divided into 6 groups : normal(Nor, n=5), control(Con, n=5), neuropathic pain plus 2 mg/kg ZP injection at GB30 and ST36(ZP-A, n=5), 10 mg/kg ZP(ZP-B, n=5), 20 mg/kg ZP(ZP-C, n=5) and 0.45 mg/kg Tramadol(Tra, n=5). Three days after the surgery, injections were administered once a day for 17 days. Withdrawal response of neuropathic rats' legs were measured by stimulating the paw of Right leg with von frey filament, acetone and radient heat on day 3, 7, 11, 15, 19 after surgery. After all treatments were completed, c-Fos in the midbrain central gray and TRPV1 & TRPA1 of DRG(L5) were analyzed. Results : Groups ZP-B and ZP-C showed a meaningful decrease in the withdrawal response of mechanical allodynia, thermal hyperalgesia and cold allodynia compared to the control group(p<0.05, p<0.01, p<0.001). Groups ZP-B and ZP-C showed a meaningful decrease in the expression of c-fos and TRPV1 protein level compared to the control group(p<0.05, p<0.01, p<0.001). Conclusions : These results suggest that Zingiberis Rhizoma Pharmacopuncture at GB30 and ST36 could decrease mechanical & cold allodynia and thermal hyperalgesia by block the TRPV1 on the model of neuropathic pain.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.1
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• pp.39-48
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• 2023

Spinal nerve injury causes mechanical allodynia and structural imbalance of neurotransmission, which were typically associated with calcium overload. Storeoperated calcium entry (SOCE) is considered crucial elements-mediating intracellular calcium homeostasis, ion channel activity, and synaptic plasticity. However, the underlying mechanism of SOCE in mediating neuronal transmitter release and synaptic transmission remains ambiguous in neuropathic pain. Neuropathic rats were operated by spinal nerve ligations. Neurotransmissions were assessed by whole-cell recording in substantia gelatinosa. Immunofluorescence staining of STIM1 with neuronal and glial biomarkers in the spinal dorsal horn. The endoplasmic reticulum stress level was estimated from qRT-PCR. Intrathecal injection of SOCE antagonist SKF96365 dose-dependently alleviated mechanical allodynia in ipsilateral hind paws of neuropathic rats with ED₅₀ of 18 ㎍. Immunofluorescence staining demonstrated that STIM1 was specifically and significantly expressed in neurons but not astrocytes and microglia in the spinal dorsal horn. Bath application of SKF96365 inhibited enhanced miniature excitatory postsynaptic currents in a dosage-dependent manner without affecting miniature inhibitory postsynaptic currents. Mal-adaption of SOCE was commonly related to endoplasmic reticulum (ER) stress in the central nervous system. SKF96365 markedly suppressed ER stress levels by alleviating mRNA expression of C/ EBP homologous protein and heat shock protein 70 in neuropathic rats. Our findings suggested that nerve injury might promote SOCE-mediated calcium levels, resulting in long-term imbalance of spinal synaptic transmission and behavioral sensitization, SKF96365 produces antinociception by alleviating glutamatergic transmission and ER stress. This work demonstrated the involvement of SOCE in neuropathic pain, implying that SOCE might be a potential target for pain management.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.273-276
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• 2009

A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient's symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient's activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.107-112
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• 2005

Background: Nerve ligation injury may produce mechanical allodynia, but this can be reversed after an intrathecal administration of adenosine analogues. In many animal and human studies, ATP-sensitive potassium channel blockers have been known to reverse the antinociceptive effect of various drugs. This study was performed to evaluate the mechanical antiallodynic effects of spinal R-PIA (Adenosine A1 receptor agonist) and the reversal of these effects due to pretreatment with glibenclamide (ATP-sensitive potassium channel blocker). Thus, the relationship between the antiallodynic effects of R-PIA and ATP-sensitive potassium channel were investigated in a neuropathic model. Methods: Male Sprague Dawley rats were prepared by tightly ligating the left lumbar 5th and 6th spinal nerves and implantation of a chronic lumbar intrathecal catheter for drug administration. The mechanical allodynia was measured by applying von Frey filaments ipsilateral to the lesioned hind paw. And the thresholds for paw withdrawal assessed. In study 1, either R-PIA (0.5, 1 and $2{\mu}g$) or saline were administered intrathecally for the examination of the antiallodynic effect of R-PIA. In study 2, glibenclamide (2, 5, 10 and 20 nM) was administered intrathecally 5 min prior to an R-PIA injection for investigation of the reversal of the antiallodynic effects of R-PIA. Results: The antiallodynic effect of R-PIA was produced in a dose dependent manner. In study 1, the paw withdrawal threshold was significantly increased with $2{\mu}g$ R-PIA (P < 0.05). In study 2, the paw withdrawal threshold with $2{\mu}g$ R-PIA was significantly decreased almost dose dependently by intrathecal pretreatment of 5, 10 and 20 nM glibenclamide (P < 0.05). Conclusions: These results demonstrated that an intrathecal injection of ATP-sensitive potassium channel blockers prior to an intrathecal injection of adenosine A1 receptors agonist had an antagonistic effect on R-PIA induced antiallodynia. The results suggest that the mechanism of mechanical antiallodynia, as induced by an intrathecal injection of R-PIA, may involve the ATP-sensitive potassium channel at both the spinal and supraspinal level in a rat nerve ligation injury model.

• Journal of Acupuncture Research
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• v.31 no.4
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• pp.57-70
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• 2014

Objectives : The purpose of this study is to examine if Clematidis Radix(CR) pharmacopuncture may be effective to the neuropathic pain(mechanical allodynia) in a rat model of neuropathic pain. Methods : To produce the model of neuropathic, L5 spinal nerve was ligated by 6-0 silk thread. After neuropathic surgery, the author examined if the animals exhibited the plantar withdrawal response of allodynia. The plantar withdrawal response was assessed by dynamic plantar aesthesiometer three days after the neuropathic surgery, CR pharmacopuncture was injected at $BL_{23}$ 1time/week for 6 weeks. After that, the author examined the plantar withdrawal response of rats' leg by dynamic plantar aesthesiometer. And also the author examined mGluR5, Bax, Bcl-2, Bax/Bcl-2 ratio in spinal cord, and c-Fos. Also the author observed the change of aspartate aminotransferase(AST), alanine aminotransferase(ALT) count in the blood serum of neuropathic rats. Results : 1. The withdrawal response of allodynia decreased in the PT3, PT4 group as compared with control group. 2. The mGluR5 increased in the PT1, PT2, PT3, and PT4 group. 3. The Bax and Bax/Bcl-2 ratio decreased in the PT4 group. 4. The c-Fos increased in the PT1 group, and decreased in the PT4 group. 5. The changes of AST in blood serum decreased in the every group excluded control group and the changes of ALT in blood serum isn't shown the signigicant change. Conclusions : These results are suggested that CR pharmacopuncture at BL23 decreased mechanical allodynia, can act on anti-apoptotic, neuroprotective effects and liver fuction in the model of neuropathic pain.

• The Journal of Korean Physical Therapy
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• v.22 no.3
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• pp.79-85
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• 2010

Purpose: Many trials for new therapeutic approaches such as stem cell-based transplantation have been conducted to improve the repair and regeneration of injured cord tissue and to restore functions following spinal cord injury (SCI) in animals and humans. Adipose tissue-derived stromal cells (ATSCs) have multi-lineage potential to differentiate into cells with neuron-like morphology. Most studies of stem cell transplantation therapy after SCI are focused on cellular regeneration and restoration of motor function, but not on unwanted effects after transplantation such as neuropathic pain. This study was focused on whether transplantation of ATSCs could facilitate or attenuate hindpaw pain responses to heat, cold and mechanical stimulation, as well as on improvement of locomotor function in a rat with SCI. Methods: A spinal cord injury rat model was produced using an NYU impactor by dropping a 10 g rod from a height of 25 mm on to the T9 segment. Human ATSCs (hATSCs; approximately $5{\times}10^5$ cells) or DMEM were injected into the perilesional area 9 days after the SCI. After transplantation, hindpaw withdrawal responses to heat, cold and mechanical allodynia were measured over 7 weeks. Motor recovery on the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale and on the inclined plane test were also evaluated. Results: The present study demonstrated that increased hindpaw withdrawal responses to cold allodynia was observed in both groups after transplantation, but the development of cold-induced allodynia in the hATSC transplantation group was significantly larger than in the control group. The difference between the two groups in locomotor functional improvement after SCI was also significant. Conclusion: Careful consideration not only of optimal functional benefits but also of unintended side effects such as neuropathic pain is necessary before stem cell transplantation therapy after SCI.

• Korean Journal of Acupuncture
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• v.28 no.2
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• pp.37-47
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• 2011

Objectives : We have studied the effects of GaAlAs (808 nm) low level laser therapy (LLLT) and acupuncture at BL40 on neuropathic pain in rats induced by lumbar spinal nerve 5 ligation. Methods : To produce the model of neuropathic pain, under isoflurane 2.5% anesthesia, the lumbar spinal nerve 5 was ligated by 6-0 silk thread. After neuropathic surgery, we examined if the animals exhibited the behavioral sign of allodynia. The allodynia was assessed by stimulating the medial malleolus with von Frey filament and acetone. Three weeks after the neuropathic surgery, GaAlAs (808 nm) low level laser and acupuncture was inserted at BL40 once a day for 6 days. We examined the withdrawal response of neuropathic rats' legs by von Frey filament and acetone stimulation. And also the author examined c-Fos, nociceptin and nociceptin receptor in the midbrain central gray of neuropathic rats. Results : The GaAlAs (808 nm) low level laser therapy and acupuncture at BL40 decreased the withdrawal response of mechanical allodynia that assessed with von Frey filament in LLLT group on 5 and 6 times and with acetone in AT group and LLLT on 6times. The LLLT and acupuncture at BL40 decreased the c-Fos protein expression in AT and LLLT groups. The 808 nm LLLT and acupuncture at BL40 decreased the nociceptin protein and nociceptin receptor protein in LLLT group. Conclusions : We have noticed that GaAlAs (808 nm) LLLT and acupuncture at BL40 decreased mechanical allodynia in the model of neuropathic pain. c-Fos, nociceptin and nociceptin receptor expression in the central gray of that group was also decreased. This study can be used as a basic resource on a study and a treatment of pain.