• Journal of Oriental Neuropsychiatry
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• v.11 no.1
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• pp.1-18
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• 2000

To study the effects of Ramulus et Uncus Uncariae (REUU) on oxygen free radical-mediated damage by hydrogen peroxide $(H_{2}O_{2})$ on cultured spinal sensory neurons, in vitro assays such as MTT assay, NR assay, neurofilament enzymeimmuno assay (EIA), sulforhodamine B (SRB) assay, assay for lactate dehydrogenase (LDH) activity and assay for lipid peroxidation were used in cultured spinal dorsal root ganglion neurons derived from mice, Spinal dorsal root ganglion neurons were cultured in media containing various concentrations of $H_{2}O_{2}$ for 5 hours, after which the neurotoxic effect of $H_{2}O_{2}$ was measured by in vitro assay. The protective effect of the herb extract, Ramulus et Uncus Uncariae (REUU) against H2O2-induced neurotoxicity was also examined. The results are as follows. 1. In NR assay and MTT assay, $H_{2}O_{2}$ significantly decreased the cell viability of cultured mouse spinal dorsal root ganglion neurons according to exposure concentration in these cultures. An additional time course study was done on these cultures. 2. Cultured spinal dorsal root ganglion neurons which were exposed to various concentrations of $H_{2}O_{2}$ showed a quantitative decrease of neuronal cells by EIA and of total protein by sulforhodamine B (SRB) assay, while they showed an increase of both lipid peroxidation and LDH activity. 3. The effect of Ramulus et Uncus Uncariae (REUU) on $H_{2}O_{2}$ induced neurotoxicity showed a quantitative increase in both neurofilament and total protein, but showed a decrease of lipid peroxidation and LDH activity. These results suggest that $H_{2}O_{2}$ has a neurotoxic effect on cultured spinal dorsal root ganglion neurons from mice and that the herb extract, Ramulus et Uncus Uncariae (REUU), was very effective in protecting $H_{2}O_{2}$ induced neurotoxicity by decreasing lipid peroxidation and LDH activity.

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.84.1-84.1
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• 2006

• The Korean Journal of Pain
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• v.19 no.1
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• pp.22-32
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• 2006

Background: This study was conducted to investigate the roles of the spinal and peripheral ${\gamma}$-aminobutyric acid (GABA)- ergic systems for the mechanical hypersensitivity produced by chronic compression of the dorsal root ganglion (CCD). Methods: CCD was performed at the left 5th lumbar dorsal root ganglion. The paw withdrawal threshold (PWT) to von Frey stimuli was measured. The mechanical responsiveness of the lumbar dorsal horn neurons was examined. GABAergic drugs were delivered with intrathecal (i.t.) or intraplantar (i.pl.) injection or by topical application onto the spinal cord. Results: CCD produced mechanical hypersensitivity, which was evidenced by the decrease of the PWT, and it lasting for 10 weeks. For the rats showing mechanical hypersensitivity, the mechanical responsiveness of the lumbar dorsal horn neurons was enhanced. A similar increase was observed with the normal lumbar dorsal horn neurons when the GABA-A receptor antagonist bicuculline was topically applied. An i.t. injection of GABA-A or GABA-B receptor agonist, muscimol or baclofen, alleviated the CCD-induced hypersensitivity. Topical application of same drugs attenuated the CCD-induced enhanced mechanical responsiveness of the lumbar dorsal horn neurons. CCD-induced hypersensitivity was also improved by low-dose muscimol applied (i.pl.) into the affected hind paw, whereas no effects could be observed with high-dose muscimol or baclofen. Conclusions: The results suggest that the neuropathic pain associated with compression of the dorsal root ganglion is caused by hyperexcitability of the dorsal horn neurons due to a loss of spinal GABAergic inhibition. Peripheral application of low-dose GABA-A receptor agonist can be useful to treat this pain.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.99-104
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• 1997

In order to elucidate the cytotoxic effect of oxygen radicals on cultured spinal dorsal root ganglion(DRG) neurons derived from mouse. the neurotoxic effect of oxygen radicals w as examined after cultured DRG neurons were exposed to xanthine oxidase(XO) and hypoxanthine(HX)-oxygen radical generating system. In addition. neuroprotective effect of epidermal growth factor(EGF) against oxidant-induced neurotoxicity was also evaluated in these cultures. The results were, as follows: 1. Lethal concentration 50(LC$_{50}$) was 35mU/ml XO and 0.1mM HX in cultured DRG neurons. 2. Oxygen radicals induced the morphological changes such as the decrease of cell number and loss of neurites in these cultures. 3. EGF increased the cell viability and neurofilament in neurons damaged by oxygen radicals. From above the results, it is suggested that oxygen radicals have a cytotoxic effect on cultured DRG neurons of neonatal mouse and selective neurotrophic factors such as EGF are, effective, in blocking the neurotoxicity induced by oxygen radicals in cultured spinal DRG neurons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1305-1308
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• 2003

To evaluate the neurotoxicity of reactive oxygen species (ROS) in cultured cultured spinal dorsal root(DRG) neurons derived from neonatal mouse, Cytotoxicity was measured by MTS assay after cultured cells were grown for 3 hours in the media containing 1～60 μM hydrogen peroxide (H₂O₂). In addition the neuroprotective effect of Salviae Miltiorrhzae Radix (SMR) was measured in these cultrures. Cell viability was positively decreased in a dose- and time-dependent manner after exposure of cultured mouse DRG neurons to 30 tt M H202 for 3 hours. In the neuroprotective effect of SMR on H₂O₂-mediated toxicity, SMR prevented the H₂O₂-induced neurotoxicity in these cultures. From these results. it suggests that H₂0₂ is toxic in cultured mouse spinal motor neurons and selective herb extract such as Uncariae Ramulus Cum Uncis is effective in prevetion of the neurotoxicity induced by H₂O₂.

• The Korean Journal of Pain
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• v.7 no.2
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• pp.238-241
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• 1994

Aim of this study was to discover the projection area of the first cervical spinal nerve. Subcutaneous injection of wheat germ agglutinin-horseradish peroxidase(WGA-HRP) was done at five points of young dogs scalp and face. After two days of survival time, animals were sacrificed by perfusion through the left ventricle of the heart. Trigeminal ganglion, first and second cervical dorsal root ganglion, superior cervical ganglion, middle cervical ganglion and stellate ganglion were removed. Projection area of wheat germ agglutinin-horseradish peroxidase in vestigated into above ganglions. Projection into the first cervical dorsal root ganglion and stellate ganglion was not found. This experiment is deemed valuable for the study of neuronal connection on the central nervous system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.681-687
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• 2010

Sibjeondaebo-tang (SJDBT) is an oriental medicinal prescription for the treatments of diverse symptoms including neurological disorders. In order to investigate its potential role for neural regulation following nerve injury, neurite outgrowth of dorsal root ganglion (DRG) neurons in culture was investigated. In DRG neurons which were preconditioned by sciatic nerve injury, neurite outgrowth was enhanced by SJDBT treatment. When preconditioned DRG neurons were co-cultured with astrocytes prepared from injured spinal cord tissue, neurite outgrowth was similarly facilitated by SJDBT. Astrocytes in co-culture showed more intense signals of vimentin protein by SJDBT compared to saline control. Sukjihwang (SJH), a conventional herbal component of SJDBT prescription, did not induce any significant changes in neurite extension of DRG neurons compared to control cells. These data suggest that SJDBT may be the therapeutic agent for nervous system disorders related to nerve damage.

• Biomolecules & Therapeutics
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• v.21 no.2
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• pp.126-131
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• 2013

Neuropathic pain is a chronic pain disorder caused by nervous system lesions as a direct consequence of a lesion or by disease of the portions of the nervous system that normally signal pain. The spinal nerve ligation (SNL) model in rats that reflect some components of clinical pain have played a crucial role in the understanding of neuropathic pain. To investigate the direct effects of gabapentin on differential gene expression in cultured dorsal root ganglion (DRG) cells of SNL model rats, we performed a differential display reverse transcription-polymerase chain reaction analysis with random priming approach using annealing control primer. Genes encoding metallothionein 1a, transforming growth factor-${\beta}1$ and palmitoyl-protein thioesterase-2 were up-regulated in gabapentin-treated DRG cells of SNL model rats. The functional roles of these differentially expressed genes were previously suggested as neuroprotective genes. Further study of these genes is expected to reveal potential targets of gabapentin.

• The Korean Journal of Pain
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• v.25 no.4
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• pp.213-220
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• 2012

Background: It has been demonstrated that the expression of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and apoptotic cell death in the dorsal root ganglion (DRG) following spinal nerve constriction injury play a role in the initiation and continuation of hyperalgesia and allodynia. The present study was designed to investigate the effects of ethyl pyruvate (EP) on mechanical and cold allodynia, TNF-${\alpha}$ expression, and apoptosis in DRG after spinal nerve ligation injury. Methods: Rats were divided into 3 groups: control, pre-EP, and post-EP. EP (50 mg/kg) was intraperitoneally injected 30 minutes before (pre-EP) or after (post-EP) surgery. Behavioral tests to determine mechanical and cold allodynia were conducted before surgery and 4 and 7 days after surgery. Seven days after surgery, TNF-${\alpha}$ protein levels in DRG were evaluated by enzyme-linked immunosorbent assay, and DRG apoptosis was determined by immunohistochemical detection of activated caspase-3. Results: Treatment with EP significantly reduced mechanical and cold allodynia following spinal nerve ligation injury. TNF-${\alpha}$ protein levels in the pre-EP ($4.7{\pm}1.2$ pg/200 ${\mu}g$; P < 0.001) and post-EP ($6.4{\pm}1.8$ pg/200 ${\mu}g$; P < 0.001) groups were 2-3 times lower than the control group ($14.4{\pm}1.2$ pg/200 ${\mu}g$). The percentages of neurons and satellite cells that co-localized with caspase-3 were also significantly lower in the pre-EP and post-EP groups than the control group. Conclusions: These results demonstrate that EP has a strong anti-allodynic effect that acts through the inhibition of TNF-${\alpha}$ expression and apoptosis in DRG after spinal nerve ligation injury.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.26-38
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• 1996

In a normal state, sympathetic efferent activity does not elicit discharges of sensory neurons, whereas it becomes associated with and excites sensory neurons in a pathophysiological state such as injury to a peripheral nerve. Although this sympathetic-sensory interaction is reportedly adrenergic, involved subtypes of adrenoreceptors are not yet clearly revealed. The purpose of this study was to determine which adrenorceptor subtypes were involved in sympathetic-sensory interaction that was developed in rats with an experimental peripheral neuropathy. Using rats that received a tight ligation of one or two of L4-L6 spinal nerves 10~15 days previously, a recording was made from afferent fibers in microfilaments teased from the dorsal root that was in continuity with the ligated spinal nerve. Electrical stimulation of sympathetic preganglionic fibers in T13 or L1 ventral root (50 Hz, 2-5 mA. 0.5 ms pulse duration, 10 sec) was made to see if the activity of recorded afferents was modulated. About half of afferents showing spontaneous discharges responded to sympathetic stimulation, and had the conduction velocities in the A-fiber range. Most of the sympathetically induced afferent responses were excitation. This sympathetically induced excitation occurred in the dorsal root ganglion (DRG), and was blocked by yohimbine (${\alpha}_2$ blocker), neither by propranolol ($\beta$ blocker) not by prazosine (${\alpha}_1$ blocker). The results suggest that after spinal nerve ligation, sympathetic efferents interact with sensory neurons having A-fiber axons in DRG where adrenaline released from sympathetic nerve endings excites the activity of sensory neurons by acting on 2-adrenoreceptors. This 2-adrenoreceptor mediated excitation of sensory neurons may account for sympathetic involvement in neuropathic pain.