• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.127-132
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• 2005

We investigated whether ischemic preconditioning (IPC) protects liver against cold ischemic injury using isolated perfused rat liver. Rat livers were preconditioned by 5 minutes of ischemia and 5 minutes of reperfusion and preserved for 30 hours at $4^{\circ}C$ in University of Wisconsin solution. Livers were then reperfused for 120 minutes. Oxygen uptake and bile flow in ischemic livers markedly decreased during reperfusion. These decreases were prevented by IPC. Portal pressure was elevated in cold ischemic and reperfused livers and this elevation was prevented by IPC. Lactate dehydrogenase and purine nucleoside phosphorylase activities markedly increased during reperfusion. These increases were prevented by IPC. The ratio of reduced glutathione to glutathione disulfide was lower in ischemic livers. This decrease was prevented by IPe. Our findings suggest that IPC protects the liver against the deleterious effect of cold ischemia/reperfusion, and this protection is associated with the reduced oxidative stress.

• Biomolecules & Therapeutics
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• v.28 no.6
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• pp.512-518
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• 2020

Stroke is a leading cause of long-term disability in ischemic survivors who are suffering from motor, cognitive, and memory impairment. Previously, we have reported suppressing LPA₅ activity with its specific antagonist can attenuate acute brain injuries after ischemic stroke. However, it is unclear whether suppressing LPA₅ activity can also attenuate chronic brain injuries after ischemic stroke. Here, we explored whether effects of LPA₅ antagonist, TCLPA5, could persist a longer time after brain ischemic stroke using a mouse model challenged with tMCAO. TCLPA5 was administered to mice every day for 3 days, starting from the time immediately after reperfusion. TCLPA5 administration improved neurological function up to 21 days after tMCAO challenge. It also reduced brain tissue loss and cell apoptosis in mice at 21 days after tMCAO challenge. Such long-term neuroprotection of TCLPA5 was associated with enhanced neurogenesis and angiogenesis in post-ischemic brain, along with upregulated expression levels of vascular endothelial growth factor. Collectively, results of the current study indicates that suppressing LPA₅ activity can provide long-term neuroprotection to mice with brain ischemic stroke.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.2
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• pp.115-122
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• 2011

The aim of this study was to investigate whether matrix metalloproteinase (MMP) inhibitors attenuate neuroinflammation in an ischemic brain following photothrombotic cortical ischemia in mice. Male C57BL/6 mice were anesthetized, and Rose Bengal was systemically administered. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold white light. MMP inhibitors, such as doxycycline, minocycline, and batimastat, significantly reduced the cerebral infarct size, and the expressions of monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and indoleamine 2,3-dioxygenase (IDO). However, they had no effect on the expressions of heme oxygenase-1 and neuroglobin in the ischemic cortex. These results suggest that MMP inhibitors attenuate ischemic brain injury by decreasing the expression levels of MCP-1, TNF-${\alpha}$, and IDO, thereby providing a therapeutic benefit against cerebral ischemia.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.803-815
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• 1988

The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

• Biomedical Science Letters
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• v.24 no.4
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• pp.405-410
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• 2018

Stroke is a leading cause of death in the Korean population and remains a major health burden worldwide. The two main pathologic types of stroke are ischemic stroke and intracranial hemorrhage (ICH), but comparisons of risk factors for these have been limited. We under took a nationwide population-based study to analyze the relationship between these risk factor sand ischemic stroke and ICH. From January 2003 to December 2013, a total of 37,561 patients with newly diagnosed ischemic stroke or ICH were identified using the National Health Insurance Service data base as the study population. Multivariable logistic regression analysis was used to determine the association between baseline risk factors and presentation with ICH versus ischemic stroke. The incidence of ischemic stroke showed an increasing rend every year, while there was no significant change in the incidence of ICH. Of the several risk factors associated with stroke, old age (OR 2.35, 95% CI 2.12~2.49, P < 0.001) was more closely associated with ischemic stroke than ICH, whereas renal disease (OR 0.74, 95% CI 0.55~0.99, P = 0.04) and carotid disease (OR 0.25, 95% CI 0.17~0.35, P < 0.001) were more strongly associated with ICH. In addition, diabetes mellitus, dyslipidemia, hypertension, ischemic heart disease and male sex was associated with an increased risk of ischemic stroke. Old age was more strongly associated with ischemic stroke than ICH, while carotid stenosis and renal impairment were more closely associated with ICH risk. Classic risk factors for stroke have considerably different associations with the two main pathologic types of stroke.

• The Journal of Internal Korean Medicine
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• v.28 no.2
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• pp.262-274
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• 2007

Objective : It has been reported that two-repeats ($IL1RN^{\ast}2$) of interleukin-1 receptor antagonist (IL-1Ra) gene is associated with ischemic stroke, and that Ala allele of the common Pro12Ala polymorphism in $PPAR-{\gamma}2$ isoform is associated with reduced risk for type 2 DM and its complications. The aim of the present study is to assess the association of IL-1Ra and $PPAR-{\gamma}2$ Pro12Ala polymorphism with the presence of ischemic stroke in the case of diabetic and non-diabetic patients. Methods : Genomic DNA was obtained from 373 healthy subjects, 157 DM subjects without ischemic stroke (known DM duration ${\ge}10$ years) and 302 ischemic stroke patients (including with DM). IL-1Ra polymorphism was analysed by polymerase chain reaction (PCR), and $PPAR-{\gamma}2$ polymorphism by restriction fragment length polymorphism after PCR. Results : $IL1RN^{\ast}1/IL1RN^{\ast}2$ genotype was associated with significantly increased risk for DM (OR=2.86, P = 0.0008) and ischemic stroke (OR=2.74, P = 0.0016). Pro/Ala genotype was associated with the reduced risk for DM (OR=0.53, P = 0.0491) and ischemic stroke (OR=0.38, P = 0.0039). They were also associated with the reduced risk for ischemic stroke in the DM patients compared with DM without ischemic stroke (OR=0.25, P = 0.0321). Conclusions : $IL1RN^{\ast}2$ allele could be an accelerating factor, not a predictive marker for ischemic stroke in type 2 DM. The Pro/Ala genotype of $PPAR-{\gamma}2$ Pro12Ala polymorphism may be associated with reduced risk for ischemic stroke with type 2 DM. Therefore it could be a useful predictive marker for ischemic stroke in Korean type 2 DM.

• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.34-44
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• 1999

Ischemic damage in the selectively vulnerable populations of neurons is thought to be caused by an abnormal accumulation of intracellular calcium. It has been reported that the neurons, expressing specific calcium binding proteins, might effectively control intracellular calcium concentrations because of a high capacity to buffer intracellular calcium in the brain ischemic condition. It is uncertain that parvalbumin, one of the calcium binding proteins, can protect the neurons from the cerebral ischemic damage. Recently, treatment of kappa opioid agonists increased survival rate, improved neurological function, and decreased tissue damage under the cerebral ischemic condition. Many evidences indicate that these therapeutic effects might result from regulation of calcium concentration. This study was designed to analyze the changes of number in parvalbumin-positive neurons after cerebral ischemic damage according to timepoints after cerebral ischemic induction. In addition, we evaluated the effect of GR89696 (kappa opioid agonist) or naltrexone(non selective opioid antagonist) on the changes of number in parvalbumin expressing neurons under ischemic condition. Cerebral ischemia was induced by occluding the common carotid artery of experimental animals. The hippocampal areas were morphometrically analyzed at different time point after ischemic induction(1, 3, 5 days) by using immuno-histochemical technique and imaging analysis system. The number of parvalbumin-positive neurons in hippocampus was significantly reduced at 1 day after ischemia(p<0.05). Furthermore, the number of parvalbumin-immunoreactive neurons was dramatically reduced at 3 and 5 days after cerebral ischemic induction(p<0.05) as compared to 1 day group after ischemia, as well as sham control group. Significant reduction of parvalbumin positive neurons in CA1 region of hippocampus was observed at 1 day after cerebral ischemic induction. However, significant loss of MAP2 immunoreactivity was observed at 3 day after cerebral ischemia. The loss of parvalbumin-positive neurons and MAP2 immunoreactivity in CA1 region was prevented by pre-administration of GR89696 compared to that of saline-treated ischemic group. Furthermore, protective effect of GR89696 partially reversed by pre-treatment of naltrexone. These data indicate that parvalbumin-positive neurons more sensitively responded to cerebral ischemic damage than MAP2 protein. Moreover, this loss of parvalbumin-positive neurons was effectively prevented by the pretreatment of kappa opioid agonist. It was also suggested that the changes of number in parvalbumin-positive neurons could be used as the specific marker to analyze the degree of ischemic neuronal damage.

• The Journal of Korean Medicine
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• v.21 no.1
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• pp.91-98
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• 2000

The water extract of Seongpungtang(SPT) has commonly been used for treatment of ischemic brain damage in Oriental traditional medicine. However, little is known about the mechanism by which the water extract of SPT rescues brain cells from ischemic damage. To elucidate the protective mechanism of ischemic induced cytotoxicity, the regulation of Lipopolysaccharide (LPS) and PMA (phobol-12-myristate-13-acetate) induced iNOS expression in microglial cells was investigated. LPS and PMA treatment for 48 hr in microglial cells markedly induced nitric oxide (NO), but treatment of the cells with the water extract of SPT decreased nitrite formation. In addition, LPS and PMA treatment for 48 hr induced severe cell death in microglial cells. However treatment of the cells with the water extract of SPT did not induce significant changes compared to the control cells. Furthermore, NO production was markedly decreased by treatment of nuclear factor kappa B(NF-kB) inhibitor, pyrrolidine dithiocarbamate(PDTC). According to the above results, it is suggested that the protective effects of the water extract of SPT against ischemic brain damage may be mediated by regulation of iNOS during ischemic condition.

• Physical Therapy Korea
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• v.13 no.3
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• pp.57-66
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• 2006

Ischemic stroke results from a transient or permanent reduction in cerebral blood flow that is restricted to the territory of a major brain artery. Thus, this study was performed to examine (1) the effects of swimming exercise on the improvement of muscle atrophy, and (2) exercise and HSP 70 expression in an ischemic stroke model induced by middle cerebral artery occlusion. The results of this study were as follows: One week after ischemic stroke was induced, changes appeared in the muscle weight of the gastrocnemius muscle due to muscle atrophy in the affected side. Group II showed statistically significant difference from group III eight weeks after ischemic stroke was induced. (p<.05). One week and eight weeks after ischemic stroke was induced there was significant decrease in the relative muscle weight of the gastrocnemius muscle in each group except Group IV, while there was statistically significant increase in group II eight weeks after ischemic stroke was induced, compared to group III (p<.05). For neurologic exercise behavior tests, Group II generally had the highest score, compared to other groups. In immunohistochemical observations, Group II showed a decrease in HSP 70. The above results suggest that swimming exercise improved muscle atrophy, changed the HSP 70 expression of ischemic stroke in rats, and contributed to the improvement of exercise function.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.257-263
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• 2009

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1 ${\alpha}$ (HIF-1 ${\alpha}$) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1 ${\alpha}$ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.