• The Korean Journal of Physiology and Pharmacology
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• v.21 no.2
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• pp.145-152
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• 2017

Remote ischemic preconditioning (RIPC) is an intrinsic phenomenon whereby 3~4 consecutive ischemia-reperfusion cycles to a remote tissue (non-cardiac) increases the tolerance of the myocardium to sustained ischemia-reperfusion induced injury. Remote ischemic preconditioning induces the local release of chemical mediators which activate the sensory nerve endings to convey signals to the brain. The latter consequently stimulates the efferent nerve endings innervating the myocardium to induce cardioprotection. Indeed, RIPC-induced cardioprotective effects are reliant on the presence of intact neuronal pathways, which has been confirmed using nerve resection of nerves including femoral nerve, vagus nerve, and sciatic nerve. The involvement of neurogenic signaling has been further substantiated using various pharmacological modulators including hexamethonium and trimetaphan. The present review focuses on the potential involvement of neurogenic pathways in mediating remote ischemic preconditioning-induced cardioprotection.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.97.1-97.1
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• 2008

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.316-321
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• 2002

The purpose of this study was to examine the effect of Ga-As(Gallium-Arsenide, wave length; 904 nm) infrared laser irradiation on healing of the experimentally crush injured rat sciatic nerves. The bilateral sciatic nerves of 43 adult male Sprague-Dawley rats were compressed surgically with a straight hemostat (1 mm width). The right legs of all the rats were irradiated using a 27 mW Ga-As infrared laser (laser irradiated group). The radiation procedure was administered for 3 minutes every day for 1, 3, 5, and 7 weeks in each group. Left legs were not irradiated and served as the control group. The numbers of total myelinated axon and degenerated myelin in the sciatic nerves of bilateral legs were measured and analyzed with mage analysis system in order to make a morphological analysis of the effect of the Ga-As infrared laser on injured nerves. Total number of myelinated axons was increased with time interval, especially in the 1, 3. and 5 week of irradiated group. Conversely, the number of degenerated myelin was decreased with time interval, especially in the irradiated group. The effects in the irradiated group were more pronounced than those of the control group. In conclusion, the Ga-As infrared laser irradiation is a useful adjuvant therapy to the regeneration of the peripheral nerve injury.

• Journal of Korean Neurosurgical Society
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• v.58 no.6
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• pp.504-507
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• 2015

Objective : Our aim was to evaluate the histopathological effects of tissue adhesives on peripheral nerve regeneration after experimental sciatic nerve transection in rats and to search whether these tissue adhesives may possess a therapeutic potential in peripheral nerve injuries. Methods : This experimental study was performed using 42 female Wistar-Albino rats distributed in 6 groups subsequent to transection of right sciatic nerves. Group I underwent external circumferential neurolysis; Group II received suture repair; Group III had local polymeric hydrogel based tissue adhesive administration; Group IV received suture repair and polymeric hydrogel based tissue adhesive application together; Group V had gelatin based tissue adhesive application and Group VI had suture repair and gelatin based tissue adhesive together. After a 6-week follow-up period, biopsies were obtained from site of neural injury and groups were compared with respect to histopathological scoring based on inflammatory, degenerative, necrotic and fibrotic changes. Results : There were remarkable differences between control group and study groups with respect to inflammation (p=0.001), degeneration (p=0.002), necrosis (p=0.007), fibrosis (p<0.001) and vascularity (p=0.001). Histopathological scores were similar between study groups and the only noteworthy difference was that Group V displayed a lower score for necrosis and higher score in terms of vascularization. Conclusion : Our results imply that tissue adhesives can be useful in repair of peripheral nerve injuries by decreasing the surgical trauma and shortening the duration of intervention. Results with gelatin based tissue adhesive are especially promising since more intense vascularity was observed in tissue after application. However, trials on larger series with longer durations of follow-up are essential for reaching more reliable conclusions.

• The Korean Journal of Pain
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• v.21 no.3
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• pp.187-196
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• 2008

Background: Upregulation of one type of the pro-inflammatory chemokine (CCL2) and its receptor (CCR2) following peripheral nerve injury contributes to the induction of neuropathic pain. Here, we examined whether another type of chemokine (CCL3) is involved in neuropathic pain. Methods: We measured changes in mechanical and thermal sensitivity in the hind paws of naïve rats or rats with an L5 spinal nerve ligation (SNL) after intra-plantar injection of CCL3 or met-RANTES, an antagonist of the CCL3 receptor, CCR1. We also measured CCL3 levels in the sciatic nerve and the hind paw skin as well as CCR1 expression in dorsal root ganglion (DRG) cells from the lumbar spinal segments. Results: Intra-plantar injection of CCL3 into the hind paw of naive rats mimicked L5 SNL-produced hyperalgesia. Intra-plantar injection of met-RANTES into the hind paw of rats with L5 SNL attenuated hyperalgesia. L5 SNL increased CCL3 levels in the sciatic nerve and the hind paw skin on the affected side. The number of CCR1-positive DRG cells in the lumbar segments was not changed following L5 SNL. Conclusions: Partial peripheral nerve injury increases local CCL3 levels along the degenerating axons during Wallerian degeneration. This CCL3 binds to its receptor, CCR1, located on adjacent uninjured afferents, presumably nociceptors, to induce hyperalgesia in the neuropathic pain state.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.183-187
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• 2008

Nerve injury can lead to neuropathic pain, which is often resistant to current analgesics and interventional therapeutic methods. Extracellular signal-regulated kinase (ERK) plays important role in the induction of neuropathic pain. We explored the antinociceptive effect of curcumin and its effect on ERK in the spinal cord in the neuropathic pain model of rats induced by chronic constriction injury (CCI) of the sciatic nerve. In injured rats, mechanical allodynia, which is one of characteristics of neuropathic pain developed and the activation of ERK in spinal cord significantly increased compared with control group. However, administration of curcumin (50 mg/kg/day p.o) for 7 days started from one day before the injury prevented the development of mechanical allodynia and increase of ERK phosphorylation. These results indicate that curcumin can be a new therapeutic agent in the treatment of neuropathic pain.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.486-491
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• 2005

Physical activity can improve sensorimotor recovery after peripheral nerve injury. Growth-associated protein 43 (GAP-43) is highly correlated with neuronal development and axonal regeneration and present in large quantities in the axonal growth cone. Using immunofluorescene staining and anterograde and retorgrade techniques, we identified enhanced axonal regrowth in distal stump of the sciatic nerve 3-14 days after crush injury in rats with treadmill training. We also carried out western blot to investigate GAP-43 protein expression in injured sciatic nerve. GAP-43 protein levels were highly induced in the injured sciatic nerve 3, 7 and 14 days compared with sedentary group. Thus, the present data provide a new evidence that treadmill training promoted axonal re-growth after injury and increased GAP-43 protein levels in the regenerating nerve.

• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.589-600
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• 2005

The purposes of this study is to discuss and analyze the effect on the recovery from cut in sciatic nerve. This study used 9 weeks male rats of Sprague-Dawley family. Rat in groups 4 were treated with pulsed therapeutic ultrasound for 3 minutes. 3 times weekly at 3MHz respectively (intensity; $0.2W/cm^2,\;0.5W/Cm^2,\;10W/cm^2$); rat in group 1 received placebo ultrasound. In addition, changes of serum aspartate amino-transferase(AST) and creatine phosphokinase(CPK) levels were also demonstrated with diameter of individual muscle fasciculate and number of muscle fiber in each of three types of muscles located in gastrocnemius, soles. The results of comparing the changes in groups are as follows; 1. We found out that hypertrophic epineurium was present in sciatic nerve injured ultrasound treatment of groups. 2. In the gastrocnemius morphological investigation of the group I (control group), severe muscle atrophy were observed at the 7th days of the sciatic nerve injury. however, muscle atrophy of the group IV ($1.0W/cm^2$) were slightly recovered at the 14th days after treatment ultrasound. At the 28th days, muscular fibers were formed in polygon and were significantly recovered. 3. C-fos immunoreactive of the group II ($0.2W/cm^2$), III ($0.5W/cm^2$) were remarkably increased at the 1th day after treatment of ultrasound. Group IV were markedly deceased. 4. Brain-Derived Neurotrophic Factor(BDNF) immunoreactive of the group II, III were increased after 7 days of the sciatic nerve injury. Group IV were markedly increased from 14th days to 28th days after treatment of ultrasound. 5. A significant increase of serum AST levels were demonstrated in control group. However, serum AST levels of massage groups were significantly decreased compared to that of control group in followed order ; ($0.2W/cm^2<0.5W/cm^2<1.0W/cm^2$). 6. A significant increase of serum CK levels were demonstrated in control of group. However, serum CK levels of massage groups were significantly decreased compared to that of control group in followed order ; ($0.2W/cm^2<0.5W/cm^2<1.0W/cm^2$). The above results suggest that ultrasound treatment after peripheral nerve injury might reduce noxious stimuli, facilitate nerve recovery and effective in the functional improvement delaying muscle atrophy or degeneration.

• Journal of Biomedical Engineering Research
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• v.38 no.4
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• pp.175-182
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• 2017

Microcurrent electrical stimulation(MES) has been used to accelerate recovery of atrophied skeletal muscle. However, convincing stimulation parameters for suppressing muscle atrophy due to injured sciatic nerve remains unclear. The objective of this study was to investigate the effective intensity of MES on restraining muscle atrophy with rat model underwent sciatic nerve injury(SNI). Twenty-5-week-old Sprague Dawley male rats were equally assigned to five groups : Control group(Control, CON, n = 4), Denervation group(Denervation, D, n = 4), Denervation with MES of $22{\mu}A$ group(Denervation + $22{\mu}A$, D+22, n = 4), Denervation with MES of $100{\mu}A$ group (Denervation + $100{\mu}A$, D+100 n = 4), Denervation with MES of $400{\mu}A$ group(Denervation + $400{\mu}A$, D+400, n = 4). To induce muscle atrophy, all rats in the D, D+22, D+100, and D+400 groups, were subjected to sciatic nerve injury on their right hindlimb and allowed to have 1 week of resting period. Following this period, rats underwent daily MES(60 min/ a day, 5times/1week) for 4 weeks. After that, we investigate morphological changes in muscle volume by using in vivo micro-computed tomography at week 0, 1, 3 and 5. After 5 weeks, the muscle volume had the highest value in D+400 group, and also noticeably increased in D+100 group compared to it in D group. The results of this study imply that MES with current intensities between $100-400{\mu}A$ can suppress muscle atrophy effectively.

• Journal of Haehwa Medicine
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• v.29 no.1
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• pp.18-25
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• 2020

Objective: The goal of this study is to investigate whether peripheral axonal regeneration is affected by diabetes in experimental animals. Method: Sprague Dawely rat was injected with 45~50 mg/kg of streptozotocin (STZ) to generate an animal model of diabetes. Three months after STZ injection, sciatic nerve (2 cm length) was removed and the same length of nerve segments from STZ-injected animal or from control animal (CTL) was transplanted into STZ-injected animals (STZ-STZ and STZ-CTL respectively). Similarly, sciatic nerve segments from STZ-injected animal or from control animal were grafted into the control animals (CTL-STZ and CTL-CTL respectively). All animals were sacrificed 2 weeks after transplantation. Sciatic nerve sections were prepared and subjected to immunofluorescence staining analysis. Results: Immunofluorescence staining for NF-200 showed that distal elongation of regenerating axons reached 40~80% of proximal neve in both CTL-STZ and CTL-CTL groups. However, distal elongation in both STZ-STZ and STZ-CTL groups were 20~60% of proximal nerve. Furthermore, measurement of axonal regeneration after immuno-staining with SCG10 showed that the scores of distal elongation relative to proximal nerve were 50~90% in CTL-CTL and CTL-STZ groups and 10-60% in STZ-CTL and STZ-STZ. Conclusions: Our data showed that the levels of axonal regeneration were not affected irrespective of whether they were from STZ- or CTL graft, but were greatly reduced when the nerves were transplanted into the STZ host.