• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.1-5
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• 2004

Transient forebrain ischemia results in the delayed neuronal death in the CA1 area of the hippo-campus. The present study was performed to determine effects of aminoguanidine, a selective iNOS inhibitor, on the generation of peroxynitrite and delayed neuronal death occurring in the hippocampus following transient forebrain ischemia. Transient forebrain ischemia was produced in the conscious rats by four-vessel occlusion for 10 min. Treatment with aminoguanidine (100 mg/kg or 200 mg/kg, i.p.) or saline (0.4 ml/100 g, i.p.) was started 30 min following ischemia-reperfusion and the animals were then injected twice daily until 12 h before sacrifice. Immunohistochemical method was used to detect 3-nitrotyrosine, a marker of peroxynitrite production. Posttreatment of aminoguanidine (200 mg/kg) significantly attenuated the neuronal death in the hippocampal CA1 area 3 days, but not 7 days, after ischemia-reperfusion. 3-Nitrotyrosine immunoreactivity was enhanced in the hippocampal CA1 area 3 days after reperfusion, which was prevented by the treatment of aminoguanidine (100 mg/kg and 200 mg/kg). Our findings showed that (1) the generation of peroxynitrite in the hippocampal CA1 area 3 days after ischemia-reperfusion was dependent on the iNOS activity; (2) the postischemic delayed neuronal death was attenuated in the early phase through the prevention of peroxynitrite generation by an iNOS inhibitor.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.236-242
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• 2004

Cerebral ischemia resulting from transient or permanent occlusion of cerebral arteries leads to neuronal cell death and eventually causes neurological impairments. Bee venom has been used for the treatment inflammatory disease. In the present study, the effects of bee venom on apoptosis and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils were investigated using immunohistochemistry for cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), caspase-3, and 5-bromo-2'-deoxyuridine (BrdU). It was shown that apoptotic cell death and cell proliferation in the hippocampal dentate gyrus were significantly increased following transient global ischemia in gerbils and that treatment of bee venom suppressed the ischemia-induced increase in apoptosis and cell proliferation in the dentate gyrus. The present results also showed that 1 mg/kg bee-venom treatment suppressed the ischemia-induced increasing apoptosis, cell proliferation, and COX-2 expression in the dentate gyrus. It is possible that the suppression of cell proliferation is due to the reduction of apoptotic cell death by treatment of bee venom. In the present study, bee venom was shown to prosses anti-apoptotic effect in ischemic brain disease, and this protective effect of bee venom against ischemia-induced neuronal cell death is closely associated with suppression on caspase-3 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.73-79
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• 2000

This study investigated whether propofol, an intravenous, non-barbiturate anesthetic, could reduce brain damage following global forebrain ischemia. Transient global ischemia was induced in gerbils by occlusion of bilateral carotid arteries for 3 min. Propofol (50 mg/kg) was administered intraperitoneally 30 min before, immediately after, and at 1 h, 2 h, 6 h after occlusion. Thereafter, propofol was administered twice daily for three days. Treated animals were processed in parallel with ischemic animals receiving 10% intralipid as a vehicle or with sham-operated controls. In histologic findings, counts of viable neurons were made in the pyramidal cell layer of the hippocampal CA1 area 4 days after ischemia. The number of viable neurons in the pyramidal cell layer of CA1 area was similar in animals treated with a vehicle or a subanesthetic dose of propofol. In terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay, semiquantitative analysis of dark-brown neuronal cells was made in the hippocampal CA1 area. There was no significant difference in the degree of TUNEL staining in the hippocampal CA1 area between vehicle-treated and propofol-treated animals. These results show that subanesthetic dose of propofol does not reduce delayed neuronal cell death following transient global ischemia in Mongolian gerbils.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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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.

• Journal of Korean Neurosurgical Society
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• v.54 no.1
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• pp.1-7
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• 2013

Objective : This study was undertaken in the belief that the atypical antipsychotic drug quetiapine could prevent apoptosis in the penumbra region following ischemia, taking into account findings that show 5-hydroxytryptamine-2 receptor blockers can prevent apoptosis. Methods : We created 5 groups, each containing 6 animals. Nothing was done on the K-I group used for comparisons with the other groups to make sure adequate ischemia had been achieved. The K-II group was sacrificed on the 1st day after transient focal cerebral ischemia and the K-III group on the 3rd day. The D-I group was administered quetiapine following ischemia and sacrificed on the 1st day while the D-II group was administered quetiapine every day following the ischemia and sacrificed on the 3rd day. The samples were stained with the immunochemical TUNEL method and the number of apoptotic cells were counted. Results : There was a significant difference between the first and third day control groups (K-II/K-III : p=0.004) and this indicates that apoptotic cell death increases with time. This increase was not encountered in the drug groups (D-I/D-II : p=1.00). Statistical analysis of immunohistochemical data revealed that quetiapine decreased the apoptotic cell death that normally increased with time. Conclusion : Quetiapine is already in clinical use and is a safe drug, in contrast to many substances that are used to prevent ischemia and are not normally used clinically. Our results and the literature data indicate that quetiapine could help both as a neuronal protector and to resolve neuropsychiatric problems caused by the ischemia in cerebral ischemia cases.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.2
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• pp.15-30
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• 2011

Objectives : The present study investigated the effects of Achyranthis Radix on short-term memory, apoptotic neuronal cell death in the hippocampus following transient global ischemia in gerbils. Methods : The gerbils were divided into 5 groups(n=10); Sham operation group, ischemia-induced group, ischemia-induced and 50 mg/kg Achyranthis Radix-treated group, ischemia-induced and 100 mg/kg Achyranthis Radix-treated group, ischemia-induced and 200 mg/kg Achyranthis Radix-treated group. For this study, a step-down avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) assay, immunohistochemistry for caspase-3 and BrdU(5-Bromo-2'-deoxyuridine), and western blotting for bax, bcl-2 were performed. Results : The results revealed that ischemic injury impaired short-term memory and increased apoototic neuronal cell death in the hippocampal CA1(cornu ammonis area 1) region. Ischemic injury enhanced cell proliferation in the hippocampal CA1 region, the compensatory and adaptive process for excessive apoptosis. Achyranthis Radix treatment improved short-term memory by suppressing ischemia-induced apoptotic neuronal cell death in the hippocampal CA1 region. Also, Achyranthis Radix suppressed the ischemia-induced increase in cell proliferation in the hippocampal CA1 region. Conclusions : We showed that Achyranthis Radix alleviates ischemia-induced apoptotic neuronal cell death, thus facilitates the recovery of short-term memory impairment induced by ischemic cerebral injury.

• Biomedical Science Letters
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• v.11 no.2
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• pp.201-209
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• 2005

This study aimed to investigate the cerebroprotective effect of nociceptin on transient focal cerebral ischemia in Sprague-Dawley rats by determining the changes in regional cerebral blood flow (rCBF) and the infarct size. Right middle cerebral artery (MCA) was occluded for 2 hours, and thereafter was followed by reperfusion by an intraluminal monofilament technique. An open cranial window was made on the right parietal bone for determination of continuous changes in rCBF by laser-Doppler flowmetry. The infarct size was morphometrically determined using the 2,3,5-triphenyltetrazolium chloride technique. In normal rats, nociceptin ($0.01\~100\;nmol/kg$, Lv.) increased rCBF and decreased cerebral arterial resistance in a dose-dependent manner. Systemic arterial blood pressure was little affected by nociceptin at the doses of 0.01 and 0.1nmol/kg, but dose-dependently reduced at the doses of 1 nmol/kg or more. In transient cerebral ischemic rats, nociceptin ($0.01\~0.1$ nmol/kg, i.p.) significantly attenuated the postischemic cerebral hyperemia, and progressively increased rCBF. The improving effect of nociceptin on the postischemic rCBF response was markedly blocked by pretreatment with $[Nphe^1]nociceptin(1-13)NH_2$ (1 nmol/kg, i.p.), a selective nociceptin receptor antagonist, but not by naloxone ($3{\mu}mol/kg$, i.p.), a selective opioid receptor antagonist. The cerebral infarct size was significantly reduced by nociceptin ($0.01\~0.1$ nmol/kg) administered i.p. 5 min after MCA occlusion in transient cerebral ischemia of 2-hour MCA occlusion and 22-hour reperfusiion. It is suggested that nociceptin improves the postischemic cerebral hemodynamics and thereby has a cerebroprotective effect in transient focal cerebral ischemia.

• Molecular & Cellular Toxicology
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• v.4 no.3
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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.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.105-115
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• 2006

Fucoidan has been shown to exhibit a host of biological activities, including anti-coagulant, anti-thrombotic, anti-tumourigenic, anti-inflammatory, anti-viral, anti-complementary and neuroprotective effects. In the present study, we attempted to determine the effects of Fucoidan on both apoptosis and cell proliferation in the hippocampal CA1 region and the dentate gyrus of gerbils after the induction of transient global ischemia. This experiment involved the use of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay as well as immunohistochemisty for caspase-3 and 5-bromo-2'-deoxyuridine (BrdU). The monosaccharide composition of the purified Fucoidan which had been extracted from Laminaria religiosa was utilized in this study. The present study clearly induces that apoptotic cell death and cell proliferation in the gerbil's hippocampal regions increased significantly following the induction of transient global ischemia and the results of this study also indicate that Fucoidan exerted a suppressive effect on this observed ischemia-induced increase in apoptosis within the CA1 and dentate gyrus, and also suppressed cell proliferation in the dentate gyrus.

• Korean Journal of Acupuncture
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• v.21 no.1
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• pp.15-27
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• 2004

Objectives : Acupuncture has been used to prevent and treat the cerebrovascular accident, such as a stroke, and many studies of acupuncture and moxibustion concerning to the stroke have been undertaken in the human and various animals. Also, herbal acupuncture, namely aqua acupuncture has been applied and developed to various diseases including the cerebrovascular accident. FOLIUM ARTEMISIAE ARGYI is the dry leaf of Artemisia argyi Levl. et Vant. collected in summer before the plant blooms and used to moxibustion and has been recommended for use as an analgesic and hemostatic. In this study, effects of FOLIUM ARTEMISIAE ARGYI (艾葉)' herbal acupuncture on the $LR_3$, namely Taechung on neuroprotection after the transient forebrain ischemia were investigated in Sprague-Dawely rats. Methods : Expressions of neuronal nitric oxide synthase (nNOS) protein in the hippocampus and cortex were observed at 2 hrs after transient forebrain ischemia by immunohistochemistry. Results : Expression of nNOS protein was increased in the hippocampus and cortex at 2 hrs after transient forebrain ischemia. However, pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ significantly decreased expression of nNOS protein protein compared to ischemia group. These features were observed in the motor cortex and the hippocampus. Conclusions : These results suggest that pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ inhibits the expression of nNOS protein induced by transient forebrain ischemia and may modulate excitatory toxicity of neuron related to neuronal cell death.