• The Korean Journal of Physiology and Pharmacology
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• 제24권2호
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• pp.173-183
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• 2020

An in vitro model for ischemia/reperfusion injury has not been well-established. We hypothesized that this failure may be caused by serum deprivation, the use of glutamine-containing media, and absence of acidosis. Cell viability of H9c2 cells was significantly decreased by serum deprivation. In this condition, reperfusion damage was not observed even after simulating severe ischemia. However, when cells were cultured under 10% dialyzed FBS, cell viability was less affected compared to cells cultured under serum deprivation and reperfusion damage was observed after hypoxia for 24 h. Reperfusion damage after glucose or glutamine deprivation under hypoxia was not significantly different from that after hypoxia only. However, with both glucose and glutamine deprivation, reperfusion damage was significantly increased. After hypoxia with lactic acidosis, reperfusion damage was comparable with that after hypoxia with glucose and glutamine deprivation. Although high-passage H9c2 cells were more resistant to reperfusion damage than low-passage cells, reperfusion damage was observed especially after hypoxia and acidosis with glucose and glutamine deprivation. Cell death induced by reperfusion after hypoxia with acidosis was not prevented by apoptosis, autophagy, or necroptosis inhibitors, but significantly decreased by ferrostatin-1, a ferroptosis inhibitor, and deferoxamine, an iron chelator. These data suggested that in our SIR model, cell death due to reperfusion injury is likely to occur via ferroptosis, which is related with ischemia/reperfusion-induced cell death in vivo. In conclusion, we established an optimal reperfusion injury model, in which ferroptotic cell death occurred by hypoxia and acidosis with or without glucose/glutamine deprivation under 10% dialyzed FBS.

• Applied Microscopy
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• 제19권1호
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• pp.1-18
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• 1989

허혈로 인하여 손상을 받은 심근세포의 기능을 재건하기 위하여 재관류가 반드시 이로운가하는 것에 대하여는 논란이 많다. 따라서 저자는 체중 500그람 내외의 기니피그를 실험재료로 하여 일과성허혈(10분) 및 일과성허혈후 재관류시(20분) 좌심실 심근세포의 미세구조 및 칼슘분포의 변화를 비교관찰하여 재관류가 심근세포재건에 어느정도 도움을 줄 수 있는가를 알아보고자 하였다. 대조군에서는 심근세포의 미세구조가 비교적 잘 보존되어 있었으며 심근세포막 및 사립체내에서 20nm 크기 정도의 칼슘침착을 볼 수 있었다. 이에 반하여 일과성허혈후, 대부분의 심근세포에서는 세포막손상, I 대의 확장, 사립체의 종창, 세포내 수분축적, 당원과립의 고갈, 지방소적유령(ghost)의 출현, 염색질의 응집 및 변연부로의 이동, 세포연접의 분리 등의 미세구조의 변화와 심근세포막 및 사립체내에서 칼슘침착의 현저한 감소를 볼 수 있었으나, 비가역성의 변화는 찾아 볼 수 없었다. 그러나 허혈후 재관류시 일부의 심근세포에서는 큰 변화를 보이지 않았지만, 많은 세포에서 이러한 미세구조의 변화는 보다 심해져 국소적으로 근절(sarcomere)의 과이완 및 striation pattern의 소실, 세포부종 등이 현저해졌으나, 세포막 및 사립체내에서는 대조군에서와 같이 칼슘침착이 재출현하였다. 이상의 결과로 미루어 일과성허혈후 재관류는 심근세포의 칼슘 조절기능 회복에 어느정도 도움을 줄 수 있으나 허혈성 손상을 악화시킬 가능성도 있을 것으로 생각된다.

• 한국보건간호학회지
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• 제28권3호
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• pp.565-573
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• 2014

Purpose: Health Insurance Review & Assessment Service (HIRA) launched an Acute Myocardial Infarction(AMI) assessment for the Payment For Performance(Quality Incentives) Pilot Project from July 2007. Assessment measures of AMI were composed of five process measures and one outcome measure, and each measure was incorporated into one composite quality score to Pay for Performance. Method: For calculation of composite quality score, we considered weighting for the measures using the Delphi method. The questionnaire was composed of three measure groups, 'Reperfusion rate'(Fibrolytic therapy received within 60 minutes of hospital arrival, Primary Percutaneous Coronary Intervention within 120 minutes of hospital arrival), 'Medication prescription rate'(Aspirin at arrival, Aspirin prescribed at discharge, Beta-blocker prescribed at discharge) and 'Survival Index'(30-day mortality rate). Result: A panel composed of 18 and completed a questionnaire by allocation of 10 scores to the three above mentioned measure groups. The Delphi was carried out until three rounds of surveys. In conclusion, each measure group was weighted differently and the 10 scores were allocated as 4.5 to 'Reperfusion rate', 2.5 to 'Medication prescription rate', and 3.0 to 'Survival Index'. Conclusion: The results of this study proposed the calculation method for weighting of Acute Myocardial Infarction quality indicators.

• The Korean Journal of Physiology and Pharmacology
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• 제10권4호
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• pp.181-186
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• 2006

This study was undertaken to evaluate whether peroxisome proliferator-activated-receptor-gamma $(PPAR-{\gamma})$ agonist-rosiglitazone (ROSI) induces postischemic functional recovery in Langendorf heart model. Hearts isolated from normal rats were subjected to 20 min of normoxia or 25 min zero-flow ischemia followed by 50 min reperfusion. In this acute protocol, ROSI $(20\;{\mu}g/ml)$ administered 10 min before ischemia had no effect on hemodynamic cardiac function, but had protective effect on lipid peroxidation in in vitro experiments. In chronic protocol in which ROSI was given by daily gavage (4 mg/kg) for three consecutive days, ROSI could not prevent the hemodynamic alteration on cardiac performance, but has protective effect on the activity of superoxide dismutase (SOD). There was no significant difference in the contents of reduced glutathione (GSH) and catalase activity between ischemia-reperfusion (IR) and ROSI treated IR hearts. Although ROSI had no effect on hemodynamic factor, it had effect on antioxidant activity. Our results indicate that ROSI provides partial beneficial effects by inhibiting lipid peroxidation and/or recovering normal level of SOD activity in the ischemic reperfused heart.

• Journal of Chest Surgery
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• 제23권6호
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• pp.1090-1106
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• 1990

This study was undertaken to investigate whether adenosine administered during cardioplegic arrest could enhance myocardial protection and improve recovery of function after ischemia. Isolated Langendorff-perfused rat hearts were subjected to 40 minutes of normothermic [37oC] ischemia. Control hearts [n=10] received modified St. Thomas’ cardioplegic solution, and the remaining hearts received modified St. Thomas’ cardioplegic solution with either 20 \ulcornerM [n=10], 200 \ulcornerM [n=10] adenosine. After ischemia of 40 minutes and 30 minutes of reperfusion, left ventricular contractility was superior in all groups of adenosine-treated hearts compared with control hearts. Furthermore, there was a significant incremental increase in functional recovery with increasing dose of adenosine. Post-ischemic diastolic stiffness was significantly better in all adenosine groups compared with controls. No differences were noted in coronary flow or myocardial water content between adenosine-treated and control hearts. These data demonstrate that adenosine administered in these concentrations provides myocardial protection, preservation of myocardial ATP and creatine phosphokinase and improved post-ischemic functional hemodynamic recovery after normothermic ischemia, presumably metabolically by reducing depletion of adenosine triphosphate, inducing rapid cardiac arrest and enabling improved post-ischemic recovery.

• The Korean Journal of Physiology and Pharmacology
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• 제14권1호
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• pp.1-9
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• 2010

AMP-activated protein kinase (AMPK) protects various tissues and cells from ischemic insults and is activated by many stimuli including mechanical stretch. Therefore, this study investigated if the activation of AMPK is involved in stretch-induced cardioprotection (SIC). Intraventricular balloon and aorto-caval shunt (ACS) were used to stretch rat hearts ex vivo and in vivo, respectively. Stretch preconditioning reduced myocardial infarct induced by ischemia-reperfusion (I/R) and improved post-ischemic functional recovery. Phosphorylation of AMPK and its downstream substrate, acetyl-CoA carboxylase (ACC) were increased by mechanical stretch and ACC phosphorylation was completely blocked by the AMPK inhibitor, Compound C. AMPK activator (AICAR) mimicked SIC. Gadolinium, a blocker of stretch-activated ion channels (SACs), inhibited the stretch-induced phosphorylation of AMPK and ACC, whereas diltiazem, a specific L-type calcium channel blocker, did not affect AMPK activation. Furthermore, SIC was abrogated by Compound C and gadolinium. The in vivo stretch induced by ACS increased AMPK activation and reduced myocardial infarct. These findings indicate that stretch preconditioning can induce the cardioprotection against I/R injury, and activation of AMPK plays an important role in SIC, which might be mediated by SACs.

• Preventive Nutrition and Food Science
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• 제6권1호
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• pp.43-50
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• 2001

The effects of cardiac ischemia-reperfusion and $\beta$-adrenergic stimulation on metabolic function and energetics were investigated in Lan gendorff-perfused spontaneously hypertensive rat (SHR) hearts. Sarcoplasmic reticulum {TEX}$Ca^{2+}${/TEX}-dependent ATPase and cardiac lactate dehydrogenase (LDH) are additionally studied. The perfusion medium (1.0 mM {TEX}$Ca^{2+}${/TEX}) contained 5 mM glucose(+5 U/L insulin) and 2 mM pyruvate as substrates. Global ischemia was induced by reducing perfusion pressure of 100 to 40 cm {TEX}$H_{2}${/TEX}O, followed by 20 min reperfusin. Isoproterenol (ISO, 1$\mu$M) was infused for 10 min. Coronary vascular resistance and myocardial oxygen consumption ({TEX}$MVO_{2}${/TEX}) of SHR were increased in parallel with enhanced venous lactate during ischemia and reperfusion compared to those of Sprague Dawley (SD) hearts. Although ischemia-induced increase in venous lactate and combined adenosine plus inosine was abolished, coronary vasodilation produced in SD during reperfusion. In SHR, depressed reactive hyperemia was associated with a fall in cardiac ATP and CrP/Pi ratio and a rise in intracellular lactate/Pyruvate ratio. On the other hand, ISO produced coronary functional hyperemia and an increase in {TEX}$MVO_{2}${/TEX}. However, these responses were less than those in SHR hearts. The ATPase activity of SHR was attenuated in free {TEX}$Ca^{2+}${/TEX} concentrations used under basal condition and with ISO compared to that of SD. Venous lactate output and cardiac LDH activity were augmented in SHR as influenced by ISO. These results demonstrate that coronary reactive and functional hyperemia was dpressed in SHR, which cold be explained by alterations in the cytosolic phosphorylation potential and the cytosolic redox state manipulated by LDH, and by abnormal free calcium handling.

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.354-361
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• 1999

In this study, the effects of tauroursodeoxycholic acid (TUDCA) on ischemia/ reperfusion injury were investigated on isolated heart perfusion models. Hezrts were perfused with oxygenated Krebs-henseleit solution (pH 7.4, $37^{\cire}C$) on a Langendorff apparatus. After equilibration, isolated hearts were treated with TUDCA 100 and 200 $\mu\textrm{M}$ or vehicle (0.02% DMSO) for 10 min before the onset of ischemia in single treatment group. In 7 day pretreatment group. TUDCA 50, 100 and 200 mg/kg body weight were given orally for 7 days before operation. After global ischemia (30 min), ischemic hearts were reperfused for 30 min. The physiological (i.e. heart rate, left ventricdular developed pressure, coronary flow, double product, time to contracture formation) and biochemical (lactate dehydrogenase; LDH) parameters were evaluated. In vehicle-treated group, time to contracture formation was 810 sec during ischemia, LVDP was 34.0 mmHg at the endpoint of reperfusion and LDH activity in total reperfusion effluent was 34.3 U/L. Single treatment with TUDCA did not change the postischemic recovery of cardiac function, LDH and time to contractur compared with ischemic control group. TUDCA pretreatment showed the tendency to decrease LDH release and to increase time to contracture and coronary flow. Our findings suggest that TUDCA does not ameliorate ischemia/reperfusion-reduced myocardial damage.

• Applied Microscopy
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• 제20권1호
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• pp.65-76
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• 1990

The effect of calcium-free reperfusion for 5, 10, and 15 minutes, respectively, followed by continuous reperfusion with normal Tyrode solution containing 1.0mM calcium chloride, after global ischemia in the isolated perfused guinea pig heart by Langendorff techniques was examined with transmission electron microscope. Compared to the nomal Tyrode solution-perfused control hearts, the 5 minute calcium-free-reperfused hearts showed loss or thickening of Z lines, focal sarcolemmal disruption, mitochondrial swelling, clumping of chroma-tin, intracellular fluid accumulation, and some separation of cell junctions, especially the fasciae adherentes. These changes became more severe in the hearts of 10 minute calcium-free reperfusion. Subsarcolemmal larger bleb and near complete separation of cell junctions were noticed. In the 15 minute calcium-free-reperfused hearts, irreversible ultrastructural changes including contraction bands, biazrre mitochondria, and sarcolemmal destruction were widely distributed. The severity of myocardial changes were in accordance with the duration of calcium-free reperfusion. These changes indicate that calcium-free reperfusion regardless of its duration could not salvage the post-ischemic myocardium probably due to development of calcium paradox.

• 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.199-199
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• 1998

In this study, the effects of ursodeoxycholic acid (UDCA) on ischemia/reperfusion injury were investigated on retrograded aortic perfusion model. Hearts from Sprague-Dawley rats were perfused with oxygenated Krebs-Henseleit solution (pH 7.4, 37) on a Langendorff apparatus. After equilibration, hearts were treated with ursodeoxycholic acid 10, 20, 40 and 800 M or vehicle (0.04% DMSO) for 10 min before the onset of ischemia. Following 25 min of global ischemia, ischemic hearts were reperfused and allowed to recover for 30 min. The physiological (i.e. heart rate, left ventricular diastolic pressure, coronary flow and time to contracture formation) and biochemical (lactate dehydrogenase, LDH) endpoints were evaluated. In vehicle group, time to contracture formation (TTC) value was 19.5 min during ischemia, LVDP was 20.8 mmHg at the endpoint of reperfusion and LDH activity in reperfusate was 59.7 U/L. Cardioprotective effects of UDCA following ischemia/reperfusion consisted of a reduced TTC (EC$\_$25/ = 16.10 M), reduced LDH release and enhanced recovery of contractile function during reperfusion. Especially, the treatments of UDCA 80 M remarkably increased LVDP (68.1 mmHg) and reduced LDH release (33.2 U/L). Our findings suggest that UDCA ameliorates ischemia/reperfusion-induced myocardial damage, in agreement with physiological and biochemical parameters.