• 대한한의학회지
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• 제30권2호
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• pp.1-16
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• 2009

Objectives: This study investigated the effect of Yukmijihwangtang on cerebral ischemia-induced learning and memory impairment by middle cerebral artery (MCA) occlusion in rats. Methods: The ability of learning and memory of rats was measured using the eight-arm radial maze and the passive avoidance test, and profile of cholinergic neuron was assessed in the medial septum and hippocampus region by immuno-histochemistry. Results: 1. No differences were found between groups in the number of correct choices in acquisition performance during the eight-arm radial maze task. 2. No differences were found between groups on day 1 in the error rate in acquisition performance, which is defined as the number of enters into the same arm more than once within five minutes. After 5 to 6 days of test, the number of errors was significantly reduced in the Yukmijihwangtang group (forebrain ischemia group with Yukmijihwangtang treatment), compared with the ischemia group. 3. The memory processes significantly improved in the Yukmijihwangtang group according to results of the passive avoidance test. 4. The appearance of AchE (acetylcholinesterase) in the CA1 region of hippocampus significantly decreased in the ischemia group, compared with the sham group (untreated group). The appearance of AchE in the same region significantly increased in the Yukmijihwangtang group, compared with the ischemia group. 5. The appearance of ChAT (choline acetyltransferase) in the CA1 region of the hippocampus and medial septum decreased in the ischemia group, compared with the sham group. The appearance of ChAT in the same region significantly increased in the Yukmijihwangtang group, compared with the ischemia group Conclusions: This study provides evidence that Yukmijihwangtang is effective for reviving the ability of learning and memory and damaged neurons in rats with experimental cerebral ischemia.

• 동국한의학연구소논문집
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• 제7권2호
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• pp.149-154
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• 1999

생쥐의 전뇌허혈(全腦虛血) 모델에서 potassium cyanide 유발(誘發) 혼수시간(昏睡時間) 및 생존시간(生存時間), 감압성(減壓性) 무효소(無酵素) 부하시(負荷時) 생존시간(生存時間)을 측정(測定)하여 전뇌처혈시(全腦處血時) 뇌순환대사(腦循環代謝) 개선(改善) 효과(效果)를 관찰(觀察)하였다. KCN 유발(誘發) 혼수시간(昏睡時間)의 단축(短縮), 치사양(致死量)의 KCN에 대한 생존시간(生存時間)의 연장(延長), 감압(減壓)에 의한 무산소(無酸素) 부하시(負荷時) 생존시간(生存時間)의 연장(延長) 효과(效果)가 나타났다.

• 동의생리병리학회지
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• 제18권2호
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• pp.538-543
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• 2004

Objective : This study investigated a neuroprotective effect of Puerariae Radix on cerebral ischemia. Method : The global cerebral ischemia was induced by bilateral common carotid arteries occlusion under hypotension (40mmHg) in Sprague-Dawley rats. After the treatment of Puerariae Radix extract, changes of c-Fos and c-Jun expressions, immediate early genes expressed by cerebral ischemia, in the hippocampus were observed immunohistochemically. Result: The results obtained are as follows; The significant increases of c-Fos and c-Jun expressions were observed in the hippocampus of the ischemic damaged rat brains. Then Puerariae Radix treatment demonstrated significant decreases of c-Fos and c-Jun expressions in CA1 region and dentate gyrus as compared with control group. On the upregulated c-Fos expression induced by cerebral ischemia, Puerariae Radix treatment demonstrated significant decreases of c-Fos expressions in CA1 region (P<0.01) and dentate gyrus (P<0.05) as compared to the control group, but there were not a significant changes in CA2 and CA3 regions of the hippocampus. On the upregulated c-Jun expression induced by cerebral ischemia, Puerariae Radix treatment demonstrated significant decrease of c-Jun expression in CA1 region (P<0.05) as compared to the control group, but there were not a significant changes in CA2, CA3, and dentate gyrus of the hippocampus. Conclusion : These results suggested that Puerariae Radix reveals the neuroprotective effect through the reduction of immediate early genes, c-Fos and c-Jun, induced by cerebral ischemia.

• Journal of Korean Neurosurgical Society
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• 제30권1호
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• pp.12-19
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• 2001

Objective : Albumin is a very useful drug for the improving of cerebral blood volume and the oncotic effect in cerebral ischemia or cerebral vasospasm. The purpose of this study was to examine the morphological and neurological effect of albumin therapy on reperfusion injury following transient focal cerebral ischemia. Materials and Methods : 18 Male Sprague-Dawley rats weighing 270-320g were used. The ischemia model was produced by 2-hour period of transient middle cerebral artery occlusion with a poly-L-lysin coated intraluminal suture. The agent(20% human serum albumin[HSA]) or control solution(NaCl 0.9%) was administered intravenously at a dosage of 1% of body weight immediate after reperfusion following a 2-hour period occlusion. Neurological function was evaluated by the postural reflex and the forlimb placing test during occlusion(at 60 min) and daily for 3 days thereafter. The brain was perfusion-fixed, and infarct volumes and brain edema were measured. Results : The HSA significantly improved the neurological score in treated group. The rats of albumin treatment group showed significantly reduced total infarct volume(by 34%) and brain edema(by 81%) compared with salinetreated rats. Conclusion : HSA showed a substantial effect on the transient focal cerebral ischemia and reperfusion injury model. These results may indicate its usefulness in treating reperfusion injury patients after thrombolysis treatment for the thrombo-embolic major cerebral artery occlusions.

• 대한한방내과학회지
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• 제22권3호
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• pp.341-351
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• 2001

Object: Acori graminei rhizoma(AGR) extract is clinically used to treat the cerebral ischemia in Korea. The present study was undertaken to study the neuroprotective effect of AGR extract in middle cerebral artery occlusion(MCAO) rats. Methods: Changes of extracellular levels of glutamate, aspartate, GABA, glycine, taurine, tyrosine, alanine in striatum were collected at 20 minutes interval by in vivo microdialysis and then analyzed by HPLC(high performance liquid chromatography) in rats subjected to permanent focal cerebral ischemia induced by 2 hours of MCAO. AGR extract was orally administrated before MCAO. Different animals were used for measurement of cerebral infarction volume induced by 24 hours of MCAO with TTC staining and image analysis. Result : The infarction volume was decreased and focal cerebral ischemia - induced increase of extracellular glutamate, aspartate, and tyrosine were inhibited after the treatment of AGR extract. On the other hand, the increase of glycine and alanine not but GABA and taurine were enhenced after the treatment of AGR extract. Conclusion: These results suggest that AGR extract can playa role in protecting against cerebral ischemia by regulating extracellular levels of excitatory and inhibitory amino acid neurotransmitters.

• Archives of Reconstructive Microsurgery
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• 제8권2호
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• pp.170-175
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• 1999

Objective : Extracranial-intracranial(EC-IC) microvascular anastomosis was performed in 18 patients with hemodynamic cerebral ischemia and traumatic cerebral aneurysm, the aim of this retrospective study was to assess its value in neurosurgical field. Method : Of 18 cases, 17 case were hemodynamic cerebral ischemia and one was traumatic cerebral aneurysm. There were 14 superficial temporal artery(STA)-to-middle cerebral artery(MCA) anastomosis, 3 saphenous vein graft bypass(2 external carotid artery(ECA)-to-MCA, 1main trunk of the STA-to-MCA) and 1 radial artery bypass(ECA-to-MCA). Results : Bypass patency was confirmed by postoperative angiography in all cases except for two cases, postoperative cerebral blood flow of ischemic brain showed significant increased in all cases with good patency through bypass. Conclusion : Revascularization by EC-IC microvascular anastomosis to the ischemic brain eliminated ischemia and was associated with excellent good outcome and good patency rates.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.383-389
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• 2017

Dexmedetomidine is an ${\alpha}2$-adrenergic receptor agonist that exhibits a protective effect on ischemia-reperfusion injury of the heart, kidney, and other organs. In the present study, we examined the neuroprotective action and potential mechanisms of dexmedetomidine against ischemia-reperfusion induced cerebral injury. Transient focal cerebral ischemia-reperfusion injury was induced in Sprague-Dawley rats by middle cerebral artery occlusion. After the ischemic insult, animals then received intravenous dexmedetomidine of $1{\mu}g/kg$ load dose, followed by $0.05{\mu}g/kg/min$ infusion for 2 h. After 24 h of reperfusion, neurological function, brain edema, and the morphology of the hippocampal CA1 region were evaluated. The levels and mRNA expressions of interleukin-$1{\beta}$, interleukin-6 and tumor nevrosis factor-${\alpha}$ as well as the protein expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-${\kappa}Bp65$, inhibitor of ${\kappa}B{\alpha}$ and phosphorylated of ${\kappa}B{\alpha}$ in hippocampus were assessed. We found that dexmedetomidine reduced focal cerebral ischemia-reperfusion injury in rats by inhibiting the expression and release of inflammatory cytokines and mediators. Inhibition of the nuclear factor-${\kappa}B$ pathway may be a mechanism underlying the neuroprotective action of dexmedetomidine against focal cerebral I/R injury.

• The Korean Journal of Physiology and Pharmacology
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• 제28권3호
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• pp.239-252
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• 2024

Dexmedetomidine displays multiple mechanisms of neuroprotection in ameliorating ischemic brain injury. In this study, we explored the beneficial effects of dexmedetomidine on blood-brain barrier (BBB) integrity and neuroinflammation in cerebral ischemia/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h and reperfusion for 24 h to establish a rat model of cerebral ischemia/reperfusion injury. Dexmedetomidine (9 ㎍/kg) was administered to rats 30 min after MCAO through intravenous injection, and SB203580 (a p38 MAPK inhibitor, 200 ㎍/kg) was injected intraperitoneally 30 min before MCAO. Brain damages were evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, Nissl staining, and brain water content assessment. BBB permeability was examined by Evans blue staining. Expression levels of claudin-5, zonula occludens-1, occludin, and matrix metalloproteinase-9 (MMP-9) as well as M1/M2 phenotypes-associated markers were assessed using immunofluorescence, RT-qPCR, Western blotting, and gelatin zymography. Enzyme-linked immunosorbent assay was used to examine inflammatory cytokine levels. We found that dexmedetomidine or SB203580 attenuated infarct volume, brain edema, BBB permeability, and neuroinflammation, and promoted M2 microglial polarization after cerebral ischemia/reperfusion injury. Increased MMP-9 activity by ischemia/reperfusion injury was inhibited by dexmedetomidine or SB203580. Dexmedetomidine inhibited the activation of the ERK, JNK, and p38 MAPK pathways. Moreover, activation of JNK or p38 MAPK reversed the protective effects of dexmedetomidine against ischemic brain injury. Overall, dexmedetomidine ameliorated brain injury by alleviating BBB permeability and promoting M2 polarization in experimental cerebral ischemia/reperfusion injury model by inhibiting the activation of JNK and p38 MAPK pathways.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.218-223
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• 2008

Oxidative stress is believed to contribute to the neuronal damage induced by cerebral ischemia/reperfusion injury. The present study was undertaken to evaluate the possible antioxidant neuroprotective effect of hydroxyfullerene (a radical absorbing cage molecule) against neuronal death in hippocampal CA1 neurons following transient global cerebral ischemia in the rat. Transient global cerebral ischemia was induced in male Wistar rats by four vessel- occlusion (4VO) for 10 min. Lipid peroxidation in brain tissues was determined by measuring the concentrations of thiobarbituric acid-reactive substances (TBARS). Furthermore, the apoptotic effects of ${H_2}{O_2}$ on PC12 cells were also investigated. Cell viabilities were measured using MTT [3-(4,5-dimethylthiazolyl-2)-2,-5-diphenyltetrazolium bromide] assays. Hydroxyfullerene, when administered to rats at 0.3-3 mg/kg i.p. at 0 and 90 minutes after 4-VO was found to significantly reduce CA1 neuron death by 72.4% on hippocampal CA1 neurons. Our findings suggest that hydroxyfullerene protects neurons from transient global cerebral injury in the rat hippocampus by reducing oxidative stress and lipid peroxidation levels, which contribute to apoptotic cell death.

• Biomolecules & Therapeutics
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• 제5권4호
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• pp.402-411
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• 1997

ln order to investigate pharmacological properties of New Woohwangchungsimwon Liquid (NCL) and Woohwangchungsimwon Liquid (CL), effects of NCL and CL on cerebral ischemia and central nervous system were compared. Cerebral ischemia insult was performed using unilateral carotid artery occlusion in Mongolian gerbils. The histological observations showed a preventive effect of NCL and CL treatments with ischemia-induced brain damage. The ATP in brain tissue was decreased in vehicle-treated ischemic gerbils. This decrease was prevented by CL treatment. In contrast to what was seen with ATP, the lactate and lipid peroxide were both elevated in vehicle-treated ischemic gerbils. This elevation was inhibited by NCL and CL treatments. While NCL and CL had no effects on the hexobarbital-induced sleeping time, they prevented the seizures induced by electric shock and pentetrazol. NCL and CL showed sedative effect in rotarod and spontaneous activity test. Respiration rate and depth were increased at the high dose of NCL and CL. Furthermore, NCL and CL showed anti-stress effect. Our findings suggest that the pharmacological profile of NCL on cerebral ischemia and central nervous system are similar to that of CL.