• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.611-619
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• 2010

The purpose of this study was to examine the effects of exercise on muscle weight and Type I and II fiber cross-sectional area of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. Methods: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The Pain+Exercise (PE) group (n=21) and the Sham+Exercise (SE) group (n=20). All rats had 28 sessions of treadmill exercise at grade 10 for 30 minutes, twice/day at 10 m/min for 14 days. Body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Muscle weight and Type I, II fiber cross-sectional area of the dissected muscles were measured. Results: The PE group showed significant increases (p<.05), as compared to the SE group for body weight and total diet intake, muscle weight of the unaffected soleus and plantaris, and in Type I and II fiber cross-sectional area of unaffected three muscles and affected plantaris. Conclusion: Exercise for 14 days attenuates unaffected soleus, plantaris and gastrocnemius muscle atrophy in neuropathic pain model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1774-1780
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• 2013

The purpose of this study was to investigate the relationship between diabetic neuropathy, and glycemic control, self-management in type 2 diabetes mellitus(DM) patients. This was a cross sectional descriptive study and data were collected between May 10 and 31, 2011 using a questionnaire and medical record. The participants were 108 with DM who were treated at the endocrine medical outpatient department. The data were analyzed Pearson's correlation with SPSS WIN program. The mean scores of neuropathic pain and self-management were $9.3{\pm}1.4$(Range 0-14.64) and $5.40{\pm}0.76$(Range 1-7), respectively. There were 33.3% of the patients whose HbA1c levels are higher than 7.5%. Neuropathic pain was positively correlated with glycemic control(r=.18, p=.035), and was negatively correlated with self-management(r=-.19, p=.023).

• Korean Journal of Acupuncture
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• v.31 no.4
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• pp.195-207
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• 2014

Objectives : The purpose of this study is to examine the effects of laser acupuncture according to the wavelength(532 nm, 650 nm, 830 nm, 904 nm, and 1064 nm) at the acupoint of GB34 GB39 on neuropathic pain rat induced by tibial and sural nerve transection(TST). Methods : Neuropathic pain in rats was induced by tibial nerve and sural nerve transection. The rats were divided into the intact group, the TST control group, and the laser acupuncture therapy group. The laser acupuncture therapy groups were then divided into subgroups with 532 nm(L532), 650 nm(L650), 830 nm(L830), 904 nm(L904), and 1064 nm(L1064) laser acupuncture therapy. The acupoint of GB34 GB39 was selected, and laser acupuncture therapy was provided on both sides alternatively twice a week in a total of 6 sessions. Results : All the laser acupuncture groups showed a significant decrease in reaction time and force intensity. L532, L904, and L1064 groups showed a significant decrease in Bax, the L532 group showed a significant increase in Bcl-2, L532 and L1064 groups showed a significant decrease in the Bax/Bcl-2 ratio, and L532 and L650 groups showed a significant increase in mGluR5, as compared with the TST control group, among nerve tissue reaction. Conclusions : These results showed that laser acupuncture therapy at each of the wavelengths had some significance on neuropathic pain.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.405-416
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• 2021

Background: This study investigated the effect of intrathecal Sec-O-glucosylhamaudol (SOG) on the p38/c-Jun N-terminal kinase (JNK) signaling pathways, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-related inflammatory responses, and autophagy in a spinal nerve ligation (SNL)-induced neuropathic pain model. Methods: The continuous administration of intrathecal SOG via an osmotic pump was performed on male Sprague-Dawley rats (n = 50) with SNL-induced neuropathic pain. Rats were randomized into four groups after the 7th day following SNL and treated for 2 weeks as follows (each n = 10): Group S, sham-operated; Group D, 70% dimethylsulfoxide; Group SOG96, SOG at 96 ㎍/day; and Group SOG192, SOG at 192 ㎍/day. The paw withdrawal threshold (PWT) test was performed to assess neuropathic pain. Western blotting of the spinal cord (L5) was performed to measure changes in the expression of signaling pathway components, cytokines, and autophagy. Additional studies with naloxone challenge (n = 10) and cells were carried out to evaluate the potential mechanisms underlying the effects of SOG. Results: Continuous intrathecal SOG administration increased the PWT with p38/JNK mitogen-activated protein kinase (MAPK) pathway and NF-κB signaling pathway inhibition, which induced a reduction in proinflammatory cytokines with the concomitant downregulation of autophagy. Conclusions: SOG alleviates mechanical allodynia, and its mechanism is thought to be related to the regulation of p38/JNK MAPK and NF-κB signaling pathways, associated with autophagy during neuroinflammatory processes after SNL.

• The Korean Journal of Pain
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• v.35 no.2
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• pp.173-182
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• 2022

Background: Neurokinin-1 (NK1) and calcitonin gene-related peptide (CGRP) play a vital role in pain pathogenesis, and these proteins' antagonists have attracted attention as promising pharmaceutical candidates. The authors investigated the anti-nociceptive effect of co-administration of the CGRP antagonist and an NK1 antagonist on pain models compared to conventional single regimens. Methods: C57Bl/6J mice underwent sciatic nerve ligation for the neuropathic pain model and were injected with 4% formalin into the hind paw for the inflammatory pain model. Each model was divided into four groups: vehicle, NK1 antagonist, CGRP antagonist, and combination treatment groups. The NK1 antagonist aprepitant (BIBN4096, 1 mg/kg) or the CGRP antagonist olcegepant (MK-0869, 10 mg/kg) was injected intraperitoneally. Mechanical allodynia, thermal hypersensitivity, and anxiety-related behaviors were assessed using the von Frey, hot plate, and elevated plus-maze tests. The flinching and licking responses were also evaluated after formalin injection. Results: Co-administration of aprepitant and olcegepant more significantly alleviated pain behaviors than administration of single agents or vehicle, increasing the mechanical threshold and improving the response latency. Anxiety-related behaviors were also markedly improved after dual treatment compared with either naive mice or the neuropathic pain model in the dual treatment group. Flinching frequency and licking response after formalin injection decreased significantly in the dual treatment group. Isobolographic analysis showed a meaningful additive effect between the two compounds. Conclusions: A combination pharmacological therapy comprised of multiple neuropeptide antagonists could be a more effective therapeutic strategy for alleviating neuropathic or inflammatory pain.

• Journal of Trauma and Injury
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• v.35 no.3
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• pp.202-208
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• 2022

Purpose: There is limited research on the effects of neuropathic pain (NP) on quality of life, depression levels, and sleep quality in patients with combat-related extremity injuries. This study evaluated whether patients with combat-related extremity injuries with and without NP had differences in quality of life, sleep quality, and depression levels. Methods: A total of 98 patients with combat-related extremity injuries, 52 with NP and 46 without, were included in this cross-sectional study. The presence of NP was determined using the Leeds Assessment of Neuropathic Symptoms and Signs questionnaire. The outcome measures were a visual analogue scale (VAS), the 36-Item Short Form Survey, the Beck Depression Inventory, and the Pittsburgh Sleep Quality Index (PSQI). Results: The VAS subparameter scores for pain (all P<0.05), PSQI sleep dur ation subscale scores (P=0.025), PSQI sleep disturbance subscale scores (P=0.016), and PSQI total scores (P=0.020) were significantly higher in patients with NP than those without. Logistic regression analysis showed that VAS scores of 5 and above for average pain during the previous 4 weeks contributed independently to the prediction of NP. Conclusions: Patients with combat-related extremity injuries with NP had more pain and poorer sleep quality than those without NP. Sleep quality should be evaluated as part of the diagnostic work-up in patients with combat-related extremity injury with NP, and interventions to improve sleep quality may help manage NP in this patient group.

• The Korean Journal of Pain
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• v.35 no.4
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• pp.413-422
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• 2022

Background: The neocortex, including the medial prefrontal cortex (mPFC), contains many neurons expressing nitric oxide synthase (NOS). In addition, increasing evidence shows that the nitric oxide (NO) and opioid systems interact in the brain. However, there have been no studies on the interaction of the opioid and NO systems in the mPFC. The objective of this study was to investigate the effects of administrating L-arginine (L-Arg, a precursor of NO) and N(gamma)-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NOS) into the mPFC for neuropathic pain in rats. Also, we used selective opioid receptor antagonists to clarify the possible participation of the opioid mechanism. Methods: Complete transection of the peroneal and tibial branches of the sciatic nerve was applied to induce neuropathic pain, and seven days later, the mPFC was cannulated bilaterally. The paw withdrawal threshold fifty percent (50% PWT) was recorded on the 14th day. Results: Microinjection of L-Arg (2.87, 11.5 and 45.92 nmol per 0.25 µL) increased 50% PWT. L-NAME (17.15 nmol per 0.25 µL) and naloxonazine (an antagonist of mu opioid receptors, 1.54 nmol per 0.25 µL) inhibited anti-allodynia induced by L-Arg (45.92 nmol per 0.25 µL). Naltrindole (a delta opioid receptor antagonist, 2.45 nmol per 0.25 µL) and nor-binaltorphimine (a kappa opioid receptor antagonist, 1.36 nmol per 0.25 µL) were unable to prevent L-Arg (45.92 nmol per 0.25 µL)-induced antiallodynia. Conclusions: Our results indicate that the NO system in the mPFC regulates neuropathic pain. Mu opioid receptors of this area might participate in pain relief caused by L-Arg.

• The Korean Journal of Pain
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• v.36 no.2
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• pp.253-267
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• 2023

Background: Cancer-induced bone pain (CIBP) is considered to have both nociceptive and neuropathic components. However, the prevalence, risk factors, and impact of the neuropathic components are yet poorly understood. Methods: We estimate the prevalence of neuropathic pain (NP) features in patients with CIBP at a tertiary care pain clinic setting using the Douleur Neuropathique 4 questionnaire and evaluate their associated factors and their impact after 4 weeks of treatment using the Brief Pain Inventory questionnaire and the Edmonton Symptom Assessment System. Results: A total of 133 patients were recruited. The estimated prevalence of NP was 30.8% (95% confidence interval: 23.6%-39.1%). Initially, the patients with NP had significantly higher average pain scores (6.00 vs. 5.05, P = 0.006), higher total interference scores (5.84 vs. 4.89, P = 0.033), and symptom distress scores (35.88 vs. 26.52, P = 0.002). After 4 weeks of treatment, patients in both groups reported significantly decreased pain intensity and improved quality of life. However, the patients with NP still reported significantly higher average pain (4.61 vs. 3.58, P = 0.048), trending toward higher total interference scores (3.52 vs. 2.99, P = 0.426), and symptom distress scores (23.30 vs. 20.77, P = 0.524). From multivariate analysis, the independent risk factors for NP were younger age, pain in the extremities, and higher average pain scores. Conclusions: NP are common in patients with CIBP. These conditions negatively affect pain intensity and the patient's quality of life before and after treatment.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.52-57
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• 2006

Objective : It has been suggested that the occurrence of persistent pain signal during the early postnatal period may alter an individual's response to pain later in life. The aim of this study is to assess whether neonatal nerve injury resulted in long-lasting consequences on nociceptive system in the rat. Methods : We examined whether neuropathic pain behaviors and the changes of spinal neuropeptides [SP, CGRP, VIP and VIP] induced by peripheral nerve injury within 1 day after birth [Neonate group] were different from those at 8 weeks after birth [Mature group]. Results : The Neonate group showed more robust and long-lasting pain behaviors than the Mature group. Immunohistochemical findings demonstrated that spinal SP- & CGRP-immunoreactivities[ir] of the ipsilateral to the contralateral side increased in the Neonate group, whereas those decreased in the Mature group. In addition, increase in spinal VIP- & NPY-ir of the ipsilateral to the contralateral side was more robust in the Mature group than in the Neonate group. Conclusion : These results suggest that peripheral nerve injury in the early postnatal period may result in long-lasting and potentially detrimental alterations in nociceptive pathways.

• The Korean Journal of Pain
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• v.28 no.4
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• pp.236-243
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• 2015

Background: Chemotherapy-induced peripheral neuropathy is a major side effect of anti-cancer drugs, and our knowledge of its mechanisms is lacking. Several models for chemotherapy-induced neuropathy have been introduced. However, the outcomes of these models differ significantly among laboratories. Our object was to create a model of chemotherapy-induced neuropathy in rats with cancer. Methods: Female Sprague-Dawley rats were used. Mammary rat metastasis tumor (MRMT-1) cells were implanted subcutaneously in rats. Chemotherapy-induced peripheral neuropathy was induced by injection of cisplatin once a day for four days. The responses to mechanical and thermal stimuli were examined using von Frey filaments, acetone, and radiant heat. Results: Cisplatin (2 mg/kg/day) produced mechanical allodynia, while it did not induce cold allodynia or thermal hyperalgesia. This dose of cisplatin could work successfully against cancer. Body weight loss was not observed in cisplatin-treated rats, nor were other abnormal behaviors noted in the same rats. Conclusions: Repeated injection of intraperitoneal cisplatin induced peripheral neuropathic pain in rats. Thus, this type of rat model has broad applicability in studies related to searching for the mechanism of cisplatin-induced mechanical allodynia and agents for the treatment of neuropathic pain.