• The Korean Journal of Physiology and Pharmacology
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• 제8권4호
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• pp.187-194
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• 2004

Middle cerebral artery occlusion (MCAO) results in cell death by activation of complex signal pathways for cell death and survival. Hypothermia is a robust neuroprotectant, and its effect has often been attributed to various mechanisms, but it is not yet clear. Upstream from the cell death promoters and executioners are several enzymes that may activate several transcription factors involved in cell death and survival. In this study, we immunohistochemically examined the phosphorylation of mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase during early period of the ischemic injury, following 2 hours (h) of transient MCAO. Increased phosphorylation of ERK and p38 was observed in the vessels at 3 h, neuron-like cells at 6 and 12 h and glia-like cells at 12 h. Activation of JNK was not remarkable, and a few cells showed active JNK following ischemia. Phosphorylation of Elk-1, a transcription factor, was reduced by ischemic insult. Hypothermia attenuated the activation of ERK, p38 and JNK, and inhibited reduction of Elk-1. These data suggest that signals via different MAPK family members converge on the cell damage process and hypothermia protects the brain by interfering with these pathways.

• Advances in Traditional Medicine
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• 제8권4호
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• pp.430-439
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• 2008

Chungpaesagan-tang (CPSGT) is most frequently used to treat ischemic brain injury in tradition Korean medicine. Clinically, cerebral ischemia is likely to be accompanied by preexisting or complicating disease. However, animal models used to examine the effects of herbal medicines on cerebral ischemia have not given this issue sufficient consideration. The present study was undertaken to determine the effects of CPSGT on focal cerebral ischemia in normal and SHR rats subjected to transient middle cerebral artery occlusion (MCAO). Animals were divided into four groups: Normal (Sprague-Dawley) rats subjected to MACO (the NC+MCAO group), normal rats subjected to MCAO and then administered CPSGT (NC + MCAO + CP), SHR rats subjected to MCAO (SHR + MCAO), and SHR rats subjected to MCAO and then administered CPSGT (SHR + MCAO + CP). MCAO was performed using the intraluminal method. CPSGT was administrated orally twice (1 and 4 h) after MCAO. All animals were sacrificed at 24 h postoperatively. Brain tissues were stained with hematoxylin & eosin, to examine the effect of CPSGT on ischemic brain tissues. In addition, changes in TNF-$\alpha$ expression in ischemic areas were examined by immunostaining. CPSGT was found to significantly reduce infarction areas in normal and SHR rats and infarction volumes in SHR rats. Similarly, CPGST markedly increased neuron numbers and sizes in all treated groups, except cell sizes in SHRs. Furthermore, CPSGT reduced TNF-$\alpha$ expression in MCAO administered SHR rats. The findings of the present study suggest that CPSGT effectively ameliorates neuron damage caused by MACO-induced cerebral ischemia, and that it has a significant neuroprotective effect after cerebral ischemia in SHR.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.435-440
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• 2010

Valproic acid (VPA) is a well-known anti-epileptic and mood stabilizing drug. A growing number of reports demonstrate that VPA is neuroprotective against various insults. Despite intensive efforts to develop new therapeutics for stroke over the past two decades, all treatments have thus far failed to show clinical effect because of treatment-limiting side effects of the drugs. Therefore, a safety-validated drug like VPA would be an attractive candidate if it has neuroprotective effects against ischemic insults. The present study was undertaken to examine whether pre- and post-insult treatments with VPA protect against brain infarct and neurological deficits in mouse transient (tMCAO) and permanent middle cerebral artery occlusion (pMCAO) models. In the tMCAO (2 hr MCAO and 22 hr reperfusion) model, intraperitoneal injection of VPA (300 mg/kg, Lp.) 30 min prior to MCAO significantly reduced the infarct size and the neurological deficit. VPA treatment immediately after reperfusion significantly reduced the infarct size. The administration of VPA at 4 hr after reperfusion failed to reduce the infarct size and the neurological deficit. In the pM CAO model, treatment with VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly attenuated the infarct size, but did not affect the neurological deficit. Western blot analysis of acetylated H3 and H4 protein levels in extracts from the ischemic cortical area showed that treatment with VPA increased the expression of acetylated H3 and H4 at 2 hrs after MCAO. These results demonstrated that treatment with VPA prior to ischemia attenuated ischemic brain damage in both mice tMCAO and pMCAO models and treatment with VPA immediately after reperfusion reduced the infarct area in the tMCAO model. VPA could therefore be evaluated for clinical use in stroke patients.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.143-143
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• 1998

Antagonists acting at the glycine site of the NMDA receptor have been gaining safer alternatives for stroke therapy because they have few adverse effect competitive and noncompetitive NMDA antagonists. Therefore, the neuroprotect novel glycine site antagonist KC0244 were evaluated in a rat model of transient comparison with GV150526A in a developmental phase. Middle cerebral artery oc was produced by insertion of a silicone-coated 4-0 nylon monofilament to the o in male Sprague-Dawley rats under isoflurane anesthesia. After 90 or 120 min retracted and the ischemic tissue reperfused. In 90-min MCAO model, GV150526A was administered 30 min before MCAO or immediately after MCAO. In 120-min MC KC0244 or GV150526A (10 mg/kg, i.p.) was administered 1 hr before MCAO or imme MCAO. Infarct volume was measured 24 hr after MCAO using the 2,3,5-triphe chloride staining method. In 90-min MCAO model, treatments with GV1505 significantly reduce infarct volume although they tended to slightly reduce cor approximately 19% compared with the nontreated group. In 120-min MCAO model with GV150526A did not either significantly reduce infarct volume although the reduce total infarct volume by approximately 16% compared with the vehicle-tre However, 1-hr preischemic and immediate treatments with KC0244 reduced total i 39 and 30% (corrected total infarct volume by 44 and 32%), respectively, co vehicle-treated control group. The results suggest that KC0244 can provid against transient focal ischemic damage with greater in vivo potency than GV150

• Journal of Korean Neurosurgical Society
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• 제58권3호
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• pp.167-174
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• 2015

Objective : This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD). Methods : Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done. Results : In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis. Conclusion : Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.333-338
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• 2011

Black ginseng (BG) has been widely used as herbal treatment for improving physiological function. In order to investigate the neuroprotective action of this herbal medicine, we examined the influence of BG on the learning and memory of rats using the Morris water maze, and we studied the effects of BG on the central cholinergic system and neural nitric oxide synthesis in the hippocampus of rats with neuronal and cognitive impairment. After middle cerebral artery occlusion was applied for 2h, the rats were administered BG (100 or 400 $mgkg^{-1}$, p.o.) daily for 2 weeks, followed by training and performance of the Morris water maze test. The rats with ischemic insults showed impaired learning and memory on the tasks. Treatment with BG produced improvement in the escape latency to find the platform. Further, the BG groups showed a reduced loss of cholinergic immunoreactivity and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the hippocampus compared to that of the ISC group. These results demonstrated that BG has a protective effect against ischemia-induced neuronal and cognitive impairment. Our results suggest that BG might be useful for the treatment of vascular dementia.