• YAKHAK HOEJI
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• v.41 no.6
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• pp.829-836
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• 1997

Studies on the effect of quinones on cardiac function has been conducted with normal hearts. But not with injured hearts, I.e. ischemia/reperfusion-injured heart. Quinone compounds are known to produce oxygen free radicals during metabolism, and for this reason, quinones are implicated in the aggravation of ischemia/reperfusion injury or cardioprotection, as in the case of ischemic preconditioning depending on the experimental conditions. The present study was carried out to examine the effect of 2-chloro-3-(4-cyanophenylamino)-1.4-naphthoquinone (NQ-Y15) on cardiac function of ischemic/reperfused and normal rat hearts. In isolated perfused hearts, various functional parameters such as left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (EDP) and maximum positive and negative dP/dt ($[\pm}dP/dt_{max}$), time to contracture, heart rate (HR) and coronary flow rate (CFR) were measured before and 30 min after dosing and following 25 min ischemia/30min reperfusion. NQ-Y15 increased LVDP, +dP/$d_{max}$and -dP/$dt_{min}$ by 18%. 30%, and 40%, respectively. There were no significant changes in other haemodynamic parameters. After ischemia/reperfusion injury, pretreatment with NQ-Y15 induced a significant decrease in LVDP and $[\pm}dP/dt_{max}$, but an increase in EDP. LDH-release was not significantly increased. These results suggested that NQ-Y15 may augment the ventricular contractility but it makes hearts more vulnerable to ischemia/reperfusion injury.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.259-266
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• 2011

The aim of this study was to evaluate the preventive role of epigallocatechin-3 gallate (EGCG, a derivative of green tea) in ischemia/reperfusion (I/R) injury of isolated rat hearts. It has been suggested that EGCG has beneficial health effects, including prevention of cancer and heart disease, and it is also a potent antioxidant. Rat hearts were subjected to 20 min of normoxia, 20 min of zero-flow ischemia and then 50 min of reperfusion. EGCG was perfused 10 min before ischemia and during the whole reperfusion period. EGCG significantly increased left ventricular developed pressure (LVDP) and increased maximum positive and negative dP/dt (+/-dP/dtmax). EGCG also significantly increased the coronary flow (CF) at baseline before ischemia and at the onset of the reperfusion period. Moreover, EGCG decreased left ventricular end diastolic pressure (LVEDP). This study showed that lipid peroxydation was inhibited and Mn-SOD and catalase expressions were increased in the presence of EGCG. In addition, EGCG increased levels of Bcl-2, Mn-superoxide dismutase (SOD), and catalase expression and decreased levels of Bax and increased the ratio of Bcl-2/Bax in isolated rat hearts. Cleaved caspase-3 was decreased after EGCG treatment. EGCG markedly decreased the infarct size while attenuating the increase in lactate dehydrogenase (LDH) levels in the effluent. In summary, we suggest that EGCG has a protective effect on I/R-associated hemodynamic alteration and injury by acting as an antioxidant and anti-apoptotic agent in one.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.5
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• pp.275-280
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• 2008

A brief ischemic insult induces significant protection against subsequent massive ischemic events. The molecular mechanisms known as preconditioning (PC)-induced ischemic tolerance are not completely understood. We investigated whether kinetic changes of cyclooxygenase (COX)-2 during reperfusion time-periods after PC were related to ischemic tolerance. Rats were given PC by occlusion of middle cerebral artery (MCAO) for 10 min and sacrificed after the indicated time-periods of reperfusion (1, 2, 4, 8, 12, 18 or 24 h). In PC-treated rats, focal ischemia was induced by occlusion of MCA for 24 h and brain infarct volume was then studied to determine whether different reperfusion time influenced the damage. We report that the most significant protection against focal ischemia was obtained in rats with 8 h reperfusion after PC. Administration of indomethacin (10 mg/kg, oral) or rofecoxib (5 mg/kg, oral) 48 h prior to PC counteracted the effect of PC. Immunohistochemical analysis showed that COX-2 and HO-l protein were induced in PC-treated rat brain, which was significantly inhibited by rofecoxib. Taken together, we concluded that the kinetic changes of COX-2 expression during the reperfusion period after PC might be partly responsible for ischemic tolerance.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.1
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• pp.98-102
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• 2006

The present stuby was carried out to determine if Radix Glycyrrhizae extract exerts beneficial effect against the ischemia-induced acute renal failure in rabbits. Radix Glycyrrhizae was known to reinforce the function of the spleen and replenish Qi, remove heat and counteract toxicity, dispel phlegm and relieve cough, alleviate spasmodic pain, and to moderate drug actions. It's indications are weakness of the spleen and the stomach marked by lassitude and weakness; cardiac palpitation and shortness of breath; cough with much phlegm; spasmodic pain in the epigastrium, abdomen and limbs; carbuncles and sores. It is often used for reducing the toxic or drastic actions of other drugs. Rabbits were treated with Radix Glycyrrhizae extract via i.v., followed by renal ischemia/reperfusion. Fractional excretion of glucose and phosphate, lipid peroxidation and light microscopy were done to evaluate the beneficial effect of Radix Glycyrrhizae extract on ischemia/reperfusion induced acute renal failure. Renal ischemia/reperfusion caused increase of fractional excretion of glucose and phosphate increased in ischemia-induced animals, which was partially prevented by Radix Glycyrrhizae extract treatment. Ischemia/reperfusion increased lipid peroxidation, which was prevented by Radix Glycyrrhizae extract administration. And the beneficial effect of Radix Glycyrrhizae extract on ischemia/reperfusion induced kidney injury was shown through the light micrographic observation. These results indicate that lipid peroxidation plays a critical role in ischemia-induced acute renal failure. Radix Glycyrrhizae extract exerts the protective effect against acute renal failure induced by renal ischemia/reperfusion.

• Archives of Pharmacal Research
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• v.27 no.7
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• pp.769-775
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• 2004

Hepatic ischemia and reperfusion (l/R) predisposes the liver to secondary stresses such as endotoxemia, possibly via dysregulation of the hepatic microcirculation secondary to an imbalanced regulation of the vascular stress genes. In this study, the effect of hepatic I/R on the hepatic vasoregulatory gene expression in response to endotoxin was determined. Rats were subjected to 90 min of hepatic ischemia and 6 h of reperfusion. Lipopolysaccharide (LPS, 1 mg/kg) was injected intraperitoneally after reperfusion. Plasma and liver samples were obtained 6 h after reperfusion for serum aminotransferase assays and RT-PCR analysis of the mRNA for the genes of interest： endothelin-1 (ET-1), its receptors $ET_A$ and $ET_B$, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), heme oxygenase-1 (HO-1), cyciooxygenase-2 (COX-2), and tumor necrosis factor-a (TNF-${\alpha}$). The activities of serum aminotransferases were significantly increased in the I/R group. This increase was markedly potentiated by LPS treatment. The ET-1 mRNA was increased by LPS alone, and this increase was significantly greater in both the I/R alone and I/R ＋ LPS groups compared to the sham. There were no significant differences in ETA receptor mRNA levels among any of the experimental groups. $ET_B$ mRNA was increased by both LPS alone and I/R alone, with no significant difference between the I/R alone and I/R ＋ LPS groups. The eN OS and HO-1 transcripts were increased by I/R alone and further increased by I/R ＋ LPS. The iNOS mRNA levels were increased by I/R alone, but increased significantly more by both LPS alone and I/R ＋ LPS compared to I/R alone. The TNF-${\alpha}$ mRNA levels showed no change with I/R alone, but were increased by both LPS alone and I/R ＋ LPS. The COX-2 expression was increased significantly by I/R alone and significantly more by I/R ＋ LPS. Taken collectively, significantly greater induction of the vasodilator genes over the constriction forces was observed with I/R ＋ LPS. These results may partly explain the increased susceptibility of ischemic livers to injury as a result of endotoxemia.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.111-117
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• 2004

Hepatic microcirculatory failure is a major component of reperfusion injury in the liver. Recent data provided some evidence that endothelium-derived vasoconstrictors and vasodilators may be functionally important to the control of the total hepatic blood flow under these conditions of circulatory failure. Since Kupffer cells provide signals that regulate the hepatic response in ischemia/reperfusion (I/R), the aim of this study was to investigate the role of Kupffer cells in the I/R-induced imbalance of vasoregulatory gene expression. Rats were subjected to 60 min hepatic ischemia, followed by 5 h of reperfusion. The Kupffer cells were inactivated by gadolinium chloride ($GdCl_3$, 7.5 mg/kg body weight, intravenously) 1 day prior to ischemia. Liver samples were obtained 5 hrs after reperfusion for RT-PCR analysis of the mRNA for genes of interest: endothelin-1 (ET-1), its receptors $ET_A and ET_B$, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1). ET-1 mRNA expression was increased by I/R. mRNA levels for $ET_A$ receptors showed no change, whereas $ET_B$ receptor transcripts increased in the I/R group. The increases in ET-1 and $ET_B$ mRNA were not prevented by the $GdCI_3$ pretreatment. The mRNA levels for iNOS and eNOS significantly increased within the I/R group with no significant difference between the I/R group and the $GdCl_3$-treated I/R group. HO-1 mRNA expression significantly increased in the I/R group and this increase was attenuated by $GdCI_3$. In conclusion, we have demonstrated that an imbalance in hepatic vasoregulatory gene expression occurs during I/R. Our findings suggest that the activation of Kupffer cells is not required for I/R-induced hepatic microvascular dysfunction.

• Journal of Korean Biological Nursing Science
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• v.23 no.3
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• pp.217-226
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• 2021

Purpose: The aim of this study was to investigate the risk factors for brain reperfusion injury in ischemic stroke patients and to analyze the clinical outcomes. Methods: A retrospective study was conducted in 168 patients who underwent mechanical thrombectomy. The data were analyzed using descriptive statistics, t-test, Mann-Whitney U test, Chi-Square test, Fisher's exact test, and logistic regression with IBM SPSS/WIN 24.0. Results: Brain reperfusion injury occurred in 67 patients (39.9%) with a low favored outcome (𝛘²=6.01, p=.014). On multivariable analysis, blood urea nitrogen (Odds ratio [OR]=1.14, 95% Confidence interval [CI]=1.06-1.23), aphasia (OR=6.16, CI=1.62-23.40), anosognosia (OR=4.84, CI=1.13-20.79), presence of both aphasia and anosognosia (OR=7.33, CI=1.20-44.60), and time required to achieve targeted blood pressure (OR=1.00, CI=1.00-1.00) were identified as risk factors for brain reperfusion injury. A statistically significant difference was detected in clinical outcomes, including hemorrhagic transformation (𝛘²=6.32, p=.012), intensive care unit length of stay (Z=-2.08, p=.038), National Institute of Health Stroke scale score at discharge (Z=-3.14, p=.002), and modified Rankin Scale score at discharge (Z=-2.93, p=.003). Conclusion: This study identified the risk factors and presented the clinical outcomes of brain reperfusion injury. It is necessary to consider these risk factors for evaluating the patients and to establish nursing interventions and strategies.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.135-143
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• 2013

Objectives : The purpose of this study was to determine whether the methanol extract of Cassia mimosoides var. nomame Makino, a naturally growing plant in Korea, could prevent the renal-ischemia/reperfusion injury in a rat model or not. Methods : The radical scavenging activities of the extracts, and ascorbic acid as a positive control, were measured in vitro. At one hour after an intraperitoneal injection of the extract (400 mg/kg), renal ischemia/reperfusion injury was generated by 40 min clamping of the left renal artery in rats. After renal ischemia/reperfusion and 24 hr restoration of blood circulation, the serum creatinine concentration was measured. And the extent of epithelial cell injury and apoptosis was assessed by various staining technologies. The Bax/Bcl-2 ratio and activated caspase-3 were assessed by immunohistochemistry. Results : The extract showed a slightly lower level of radical scavenging activity than that of ascorbic acid. Compared to those of the vehicle-treated group, the extract-treated group displayed a significantly smaller tubular epithelial cell injury of 54% reduction in the outer medulla region and a lower serum creatinine concentration of 50% reduction. It seems that the reduction in cellular injury is due to the attenuation of the Bax/Bcl-2 ratio, and the inhibition of caspase-3 activation by the extract of Cassia mimosoides. Conclusions : Cassia mimosoides var. nomame Makino could be a good candidate for a prophylactic agent against the ischemia/reperfusion/induced kidney injury.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.739-748
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• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Korean Journal of Oriental Medicine
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• v.5 no.1
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• pp.111-117
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• 1999

Free radicals are thought to be the most important cause of the reperfusion injury subsequent to ischemia. The antioxidant status of the tissue affected by ischemia-reperfusion is of great importance for the primary endogenous defense against the free radical induced injury. Therefore, antioxidant therapy has been shown to be beneficial in neurological disorders such as Alzheimer's disease and cerebral ischemia. In this study, the protective effects of Chungpesagan-tang (CST) was investigated against ischemia/reperfusion-induced cytotoxicity in SK-N-MC neuronal cells It was found out that low concentration of CST was highly effective in protecting neuronal cells against ischemia/reperfusion-induced cytotoxicity. The inhibitory effect of CST on malondialdehyde formation during ischemia/reperfusion-induced oxidative stress in SK-N-MC cells showed obvious dose-dependent responses. Also, CST showed relatively high inhibitory activity to xanthine oxidase induced by ischemia/reperfusion environment Therefore, it is thought that CST has both antioxidant and xanthine oxidase inhibitory effect and can be used for clinical applications for protection of neuronal cells from ischemia-reperfusion injury.