• Proceedings of the PSK Conference
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• 2003.04a
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• pp.145.1-145.1
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• 2003

Several lines of recent evidences have shown that several pro-inflammatory genes or mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 and cytokines (e.g., tumor necrosis factor $\alpha$ and interleukin-1$\beta$), are strongly expressed in the ischemic brain. Inflammation is now recognized as a significant contributing mechanism in cerebral ischemia because anti-inflammatory compounds or inhibitors of iNOS and cyclooxygenase-2 have been proven to reduce ischemic brain damage. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.749-758
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• 1997

Myocardial ischemia-reperfusion injury is known to be mediated by reactive oxygen species. The myocardial cell is equipped with endogenous antioxidant defensive system which can be adaptively stimulated by various oxidative stress. It is postulated that an increased oxygen partial pressure induced by hyperbaric oxygenation impose an oxidative stress on the cells, resulting alterations in the endogenous antioxidant system. In this study we investigated the effect of hyperbaric oxygenation on the activities of myocardial antioxidant enzymes and observed whether the hyperbaric oxygenation could protect the ischemia-reperfusion injury of heart. Rats or rabbits were pretreated with hyperbaric $oxygenation(2{\sim}3\;atm\;O_2/1{\sim}3\;hrs/1{\sim}10\;days)$. The changes in activities of major antioxidant enzymes(superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phasphate dehydrogenase), functional recovery and infarct size were observed in the experimentally induced ischemia-reperfused hearts. In the hearts isolated from rats pretreated with $2\;atm\;O_2/1{\sim}2\;hrs$ for 5 days, the functional recovery after reperfusion(20 min) following global ischemia(25 min) was significantly increased without any observable oxygen toxicity. Lactate dehydrogenase release was also significantly reduced in this hyperbaric oxygenated rat hearts. In in vivo regional ischemia(30 min) model of rabbit hearts, pretreatrment with $2\;atm\;O_2/1\;hr$ for 5 days significantly limited the infarct size. Among the myocardial antioxidant enzymes of rat hearts pretreated with the hyperbaric oxygenation, the activities of catalase, superoxide dismutase and glucose-6-phosphatase dehydrogenase were increased, while those of glutathione peroxidase and reductase were not changed. There were lethal cases in the groups of rats exposed to 3 atm $3\;atm\;O_2/2{\sim}3\;hrs$ for 5 days. A lipid-peroxidation product, rnnlondialdehyde was increased in brains and livers of the rats exposed to$2\;atm\;O_2/2{\sim}3\;hrs/5\;days\;and\;3\;atm\;O_2/1\;hr/5days$. The present results suggest that the pretreatment of hyperbaric oxygenation can protect the post-ischemic rererfused hearts in association with a stimulation of the activities of myocardial antioxidant defensive enzymes, and that the hyperbaric oxygenation of $2\;atm\;O_2/1\;hr$for 5 days would be a safe condition which does not produce any oxygen toxicity.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.847-853
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• 1997

Although the effects of adenosine on the heart, including the clinical suppression of cardiac arrhythmias, have been recognized for more than half a century, it is only in the last decade that the therapeutic potential of adenosine has been recognized. The objective of this study was to determine if augmentation of myocardial adenosine levels during global ischemia improves functional recovery after reperfusion. We used to modified Langendonf system to evaluate myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas'Hospital cardioplegic solution used to provide myocardial protection. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegic solution. Two groups of hearts w re studied: (1) control group(n=10) cardioplegia alone; (2) adenosine group(n=10) adenosine(0.75mg/kg/min) added to the cardioplegic solution. Significantly better percent recovery(p<0.01) in hemodynamics(except heart rate) at 60 minutes after reperfusion was evident compared to baseline values in the adenosine group. (systolic no란ic pressure : 78.5$\pm$3.6% vs 66.6$\pm$5.9%, airtic overflow volume : 61.7$\pm$ 11.6% vs 37.2$\pm$ 15.4%, coronary flow volume 77.1$\pm$7.5% vs 57.2$\pm$ 11.1%, and cardiac output : 65.6$\pm$ 11.5% vs 44.2$\pm$ 12.4%). Heart rate was similar in two groups(94.4$\pm$4.8% vs 95.3 $\pm$ 6.8%). Adenosine groups resulted in significantly rapid recovery time of heart beat after reperEusion(p<0.01) (24.5$\pm$7.6 sec. vs 179.0$\pm$ 131.1sec.). In biochemical study, CPK levels(0.1 $\pm$0.3U/L vs 1.4$\pm$0.8U/L) and lactic acid levels(0.08$\pm$0.Immol/L vs 0.34$\pm$0.2 mmol/L) were significantly low in adenosine groups(p<0.01). We concluded that adenosine included cardioplegia have better recovery effects after r perfusion in myocardial ischemia compared to adenosine free cardioplegia.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.558-565
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• 2000

SK-1080 is one of the newly developed orally active nonpeptide angiotensinII $AT_1-receptor$ antagonist that selectively acts at $AT_1$ receptor with high affinity. The cardiac effect on ischemia/reperfusion injury of SK-1080 was compared with those of losartan, a prototype of this class, in isolated rat hearts. Isolated perfused rat heart was pretreated with drug for 10 min and then subjected to global ischemia for 30 min followed by reperfusion with- or without drug for 30 min. The possible additive effect of SK-1080 on the platelet aggregation and coagulation in human blood was also studied. We investigated whether SK-1080 effects the platelet aggregation induced by ADP, a platelet agonist partially dependent on $thromboxaneA_2$. The clotting times in the prothrombin time (PT) and activated partial thromboplastin time (APTT) were also examined in human plasma in vitro as coagulation screening test. SK-1080 improved reperfusion function (LVDP, left ventricular developed pressure; PRP, rate-pressure product) in a dose-dependent manner. SK-1080 reduced ADP-induced platelet aggregation compared with vehicle but less than losartan, and did not affect clotting times.

• Journal of Chest Surgery
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• v.32 no.9
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• pp.773-780
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• 1999

Background: It has been demonstrated that brief periods of calcium depletion and repletion (calcium-free preconditioning, CP) have cardioprotective effects as seen in ischemic preconditioning(IP) which enhances the recovery of post-ischemic contractile dysfunction and reduces the incidence of reperfusion-induced arrhythmia or infarct size after a prolonged ischemia. In the present study, we tested this paradoxical phenomenon in isolated rabbit hearts. Material and Method: Hearts isolated from New Zealand white rabbits(1.5∼2.0 Kg body weight) were perfused with Tyrode solution using the Langendorff technique. After stabilizing the baseline hemodynamics, the hearts were subjected to 45 minutes of global ischemia followed by 120 minutes of reperfusion with IP(IP group, n=7) or without IP (ischemic control group, n=7). IP was induced by a single episode of 5 minutes global ischemia and 10 minutes reperfusion. In the CP group(n=7), the hearts were subjected to perfusion with Tyrode solution with calcium depletion for 5 minutes and repletion for 10 minutes, and 45 minutes of ischemia and 120 minutes of reperfusion. Left ventricular function including developed pressure, dP/dt, heart rate, left ventricular end-diastolic pressure and coronary flow was measured. Infarct size was determined by staining with 1% triphenyltetrazolium chloride and planimetry. Data were analyzed by a one-way analysis of variance and Tukey's post-hoc test. Result: In comparison with the ischemic control group, IP significantly enhanced the recovery of the left ventricular function including the left ventricular developed pressure, contractility, and coronary flow; in contrast, these functional parameters of the CP group tended to be lower than those of the ischemic control group. However, the infarct size was significantly reduced by IP or CP(p<0.05). Conclusion: These results suggest that in isolated Langendorff-perfused rabbit heart model, CP(induced by single episode of 5 minutes calcium depletion and 10 minutes repletion) could not improve the post-ischemic contractile dysfunction(after a 45-minute global ischemia) but it has an infarct size-limiting effect.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.341-352
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• 2011

The purpose of this study was carried out to investigate the effect of electroacupuncture on reactive gliosis expressing GFAP in rat with transient global cerebral ischemia. Subjects were randomly divided into two groups, a control group and a electroacupuncture group on ST36, LI11 and SP9 with 2 Hz and 1 mA. The rats were sacrificed on 1, 3 and 7 days after transient cerebral ischemia using ligation of left common carotid artery. After making brain slide sections, they were immunostained with GFAP antisera(1:2,500). The results were as follows: The numbers of astrocytes of electroacupuncture group were decreased than those of control group at every 1, 2 and 7 days. Especially, the numbers of astrocytes at 3 days(p<0.01) and 8 days(p<0.05) were different statistically. And astrocytes had resting, hypertrophic and moving types on cerebral cortex. The decrease of numbers of astrocytes expressing GFAP showed that electroacupuncture could localise and minimize the brain damage by transient cerebral ischemia and cause brain cell plasticity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5019-5026
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• 2011

The purpose of this study was to investigate the effect of the increased sympathetic outflow on the changes of muscle tone and central nervous system excitability in the chronic stroke patients. This study was conducted from October 12th 2009 to December 4th 2009. 30 patients with chronic hemiplegia for at least 6 months were participated. Before and during the mental arithmetic, static handgrip and post-handgrip ischemia tasks, the central nervous system action potentials and global synkinesis level were compared. The central nerve action potentials were measured with H/Mmax ratio and V/Mmax ratio. To obtain global synkinesis level, surface electromyography data were digitized, processed to root mean square. In our study, The global synkinesis level during knee flexion and extension was decreased in the mental arithmetic and in the post-handgrip ischemia task(p<.05) but not in the grip task. Also, V/Mmax ratio was decreased all in the three task(p<.05). In conclusion, we know that the central nervous system excitability and the muscle tone in chronic hemiplegic patients were decreased by the increased sympathetic outflow.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.269-269
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• 2004

배아줄기 세포는 신경퇴행성 질환의 치료 수단으로 많은 가능성을 가지고 있는 것으로 알려져 있다. 본 연구에서는 중풍 동물모델에서 수중미로 학습을 이용하여 중풍 치료제로서 인간배아줄기 세포의 인지 및 기억력 장애에 대한 기능 회복의 효능을 검토하였고, 인간배아줄기 세포의 신경세포 보호효과를 규명하기 위하여 면역조직화학 염색법을 이용하여 해마내의 세포사멸을 측정하였으며, 인지 및 기억증진의 작용을 규명하기 위하여 아세틸콜린성 신경세포의 활성도를 측정하였다. (중략)

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.141.2-142
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.420-421
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• 2006