• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.165-175
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• 2001

Background: Recent in vivo experimental evidence suggests that isoflurane-induced cardioprotection may involve $K_{ATP}$ channel activation. However, it was demonstrated that isoflurane inhibited $K_{ATP}$ channel activities in the inside-out patch mode. To explain this discrepancy, the present investigation tested the hypothesis that a metabolite of isoflurane, trifluoroacetic acid (TFA), contributes to isoflurnae-induced cardioprotection via $K_{ATP}$ channel activation during myocardial ischemia and reperfusion. Methods: Single ventricular myocytes were isolated from rabbit hearts by an enzymatic dissociation procedure. Patch-clamp techniques were used to record single-channel currents. $K_{ATP}$ channel activities were assessed before and after the application of TFA with the inside-out patch mode. Results: TFA enhanced channel activity in a concentration-dependent fashion. The concentration of TFA for half-maximal activation and the Hill coefficient were 0.03 mM and 1.2, respectively. TFA did not affect the single channel conductance of $K_{ATP}$ channels. Analysis of open and closed time distributions showed that TFA increased burst duration and decreased the interburst interval without changes in open and closed time distributions shorter than 5 ms. TFA diminished ATP sensitivity of $K_{ATP}$ channels in a concentration-response relationship for ATP. Conclusions: TFA, a metabolite of isoflurane, enhanced $K_{ATP}$ channel activity in a concentration-dependent fashion. These results imply that TFA could mediate isoflurane-induced cardioprotection via $K_{ATP}$ channel activation during myocardial ischemia and reperfusion.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.584-590
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• 2017

Ginkgo biloba extract (EGb 761) has been widely used clinically to reduce myocardial ischemia reperfusion injury (MIRI). Microvascular endothelial cells (MVECs) may be a proper cellular model in vitro for the effect and mechanism study against MIRI. However, the protective effect of EGb 761 on MVECs resisting hypoxia/reoxygenation (H/R) injury is little reported. In this study, H/R-injured MVECs were treated with EGb 761, and then the cell viability, apoptosis, ROS production, SOD activity, caspase-3 activity, and protein level of ATM, ${\gamma}$-H2AX, p53, and Bax were measured. ATM siRNA was transfected to study the changes of protein in the ATM pathway. EGb 761 presented protective effect on H/R-injured MVECs, with decreasing cell death, apoptosis, and ROS, and elevated SOD activity. Next, EGb 761 could inhibit H/R-induced ATM, ${\gamma}$-H2AX, p53, and Bax in a dose-dependent manner. Moreover, ATM siRNA also could inhibit H/R-induced ATM, ${\gamma}$-H2AX, p53, and Bax. Overall, these findings verify that EGb 761 protects cardiac MVECs from H/R injury, and for the first time, illustrate the influence on the ATM pathway and apoptosis by EGb 761 via dampening ROS.

• Journal of Chest Surgery
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• 제23권4호
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• pp.646-653
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• 1990

Currently numerous methods are in use for myocardial protection from the ravages of ischemia and hypoxia. This study was designed to compare with FDP-GIK[Group II, n=8] and GIK cardioplegic solution[Group I, n=8] in ability of myocardial protection and was examined in the isolated working rat heart subjected to long period[120 min] of hypothermic[10 - 15K] ischemic arrest with multidose[every 30 min] cardioplegic infusion. During postischemic reperfusion period 20 min, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure, cardiac output, heart rate], biochemical enzymatic & electrical activities were evaluated. The time from onset of reperfusion to the return of regular sinus rhythm was significantly reduced from 87$\pm$3 sec to 17$\pm$2 sec[P<0.05]. The postischemic recovery of aortic flow was better in the group II [95.1$\pm$3.3% of its preischemic control level] than in the Group I [75.4$\pm$6.8%] [P<0.05]. Cardiac output and stroke volume was also better in the group[91.3$\pm$1.6%, 89.4$\pm$2.6%, respectively] than in the Group I [79.1$\pm$3.7%, 77.0$\pm$4.8%, respectively] [P<0. 05]. Creatine kinase leakage was also significantly reduced from 33.8$\pm$4.9 IU /10 min / gm * dry weight to 15.4$\pm$3.6 IU /10 min /gm * dry weight[P<0.05]. It is suggested that adding FDP to GIK cardioplegic solution improves its ability to protect the heart against long period of hypoxic ischemia.

• The Korean Journal of Physiology and Pharmacology
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• 제25권3호
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• pp.239-249
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• 2021

The present study explored the therapeutic potential of hydrogen sulfide (H2S) in restoring aging-induced loss of cardioprotective effect of remote ischemic preconditioning (RIPC) along with the involvement of signaling pathways. The left hind limb was subjected to four short cycles of ischemia and reperfusion (IR) in young and aged male rats to induce RIPC. The hearts were subjected to IR injury on the Langendorff apparatus after 24 h of RIPC. The measurement of lactate dehydrogenase, creatine kinase and cardiac troponin served to assess the myocardial injury. The levels of H2S, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), nuclear factor erythroid 2-related factor 2 (Nrf2), and hypoxia-inducible factor (HIF-1α) were also measured. There was a decrease in cardioprotection in RIPC-subjected old rats in comparison to young rats along with a reduction in the myocardial levels of H2S, CBS, CSE, HIF-1α, and nuclear: cytoplasmic Nrf2 ratio. Supplementation with sodium hydrogen sulfide (NaHS, an H2S donor) and l-cysteine (H2S precursor) restored the cardioprotective actions of RIPC in old hearts. It increased the levels of H2S, HIF-1α, and Nrf2 ratio without affecting CBS and CSE. YC-1 (HIF-1α antagonist) abolished the effects of NaHS and l-cysteine in RIPC-subjected old rats by decreasing the Nrf2 ratio and HIF-1α levels, without altering H2S. The late phase of cardioprotection of RIPC involves an increase in the activity of H2S biosynthetic enzymes, which increases the levels of H2S to upregulate HIF-1α and Nrf2. H2S has the potential to restore aging-induced loss of cardioprotective effects of RIPC by upregulating HIF-1α/Nrf2 signaling.

• 대한의생명과학회지
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• 제28권4호
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• pp.237-246
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• 2022

Ischemia-reperfusion results in excess reactive oxygen species (ROS) that affect myocardial cell damage. ROS production inhibition is effectively proposed in treating cardiovascular diseases including myocardial hypertrophy. Studies have shown that oxidizing cultured cells in in vitro experiments gradually decreases the permeability of mitochondrial membranes time- and concentration-dependent, resulting in increased mitochondrial membrane damage due to secondary ROS production and cardiolipin loss. However, recent studies have shown that 5-iodo-6-amino-1,2-benzopyrone (INH₂BP), an anticancer and antiviral drug, inhibited peroxynitrite-induced cell damage in in vitro and alleviated partial or overall inflammation in animal experiments. Therefore, in this paper, we studied the preventive effect of INH₂BP on H9c2 cells derived from mouse heart damaged by oxidative stress using 700 μM of hydrogen peroxide. As a result of oxidative stress to H9c2 cells by hydrogen peroxide whether the treatment of INH₂BP or not, hydrogen peroxide caused serious damage in H9c2 cells. These results were confirmed with cell viability and Hoechst 33342 assays. And this damage was through cell death. However, it was confirmed that H9c2 cells pretreated with INH₂BP significantly reduced cell death by hydrogen peroxide. In addition, measurements with DCF-DA assay to determine whether ROS is produced in H9c2 cells treated with only hydrogen peroxide produced ROS significantly, but H9c2 cells pretreated with INH₂BP significantly reduced ROS production by hydrogen peroxide. Taken together, it is believed that INH₂BP can be useful for the prevention and treatment of cardiovascular diseases induced through oxidative stress such as heart damage caused by ischemia/reperfusion.

• 대한약리학회지
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• 제32권1호
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• pp.31-37
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• 1996

허혈전처치(IP)의 히혈-재관류손상에 대한 심근 보호작용의 기전을 규명하기 위한 일환으로 denosine에 의한 PKC자극이 허혈전처치의 주요 기전으로 작용할 가능성을 조사하였다. 흰쥐 적출심장의 Langendorff 관류 표본에서 실험적인 허혈(30분)-재관류(20분)손상을 유도하였고, 허혈전처치는 허혈-재관류 손상 유도 전에 5분 허혈-5분 재관류를 3회 반복하여 시행하였다. 심근 손상의 지표로 심수축기능, 세포질효소 유출을 측정하였다. Adenosine이 허혈전처치의 심보호 효과에 관여하는지를 관찰하기 위하여 adenosine수용체 억제제인 8-(p-sulfophenyl)-theophylline(SPT), Xanthine amine congener(XAC) 및 8-cyclopentyl-1,3-dipropylxanthine (DPCPX)을 허혈전처치 유도 전에 투여하였다. 또한 PKC가 허혈전처치의 세포내 매개인자로 관여 할 가능성을 관찰하기 위하여 PKC활성 억제제인 polymyxin B 및 chelerythrine과 PKC translocation 억제제인 colchicine을 허혈전처치 유도 전에 투여하였다. 연구성적은 다음과 같다. 1) 허혈전처치는 허혈재관류 심장의 심기능의 저하를 현저히 회복시켜 심기능 회복률은 75%에 달하였다. 2) 허혈-재관류 심장에서 lactate dehydrogenase유출증가는 허혈전처치에 의해 현저히 저하되었다. 3) Adenosine 비선택적 차단제인 SPT와 Al 선택적 차단제인 DPCPX 및 XAC의 투여가 허혈전처치에 의한 심기능회복 및 LDH 유출 감소에 영향을 미치지 않았다. 4) PKC활성 억제제인 polymyxin B 와 chelerythrine을 처치시 히혈전처치 심장의 심기능 회복률이 현저히 감소되었으며 LHD 유출 역시 대조군 심장의 수준으로 증가하였다. 5) PKC translocation을 방해하는 colchicine도 허혈전처치의 심보호 효과를 억제시켰다. 이상의 결과들로부터 adenosine은 흰쥐 심장에서 허혈전처치의 심보호효과에 중요한 세포외 매개물질로 작용할 가능성이 희박하며, PKC는 흰쥐 심장에서 허혈전처치시 세포내 매개 인자로 관여하여 허혈전처치에 의한 심보호효과에 중요한 역할을 할 수 있으리라 사료된다.

• Journal of Chest Surgery
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• 제54권1호
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• pp.9-16
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• 2021

Background: The deposition of monomeric C-reactive protein (mCRP) in the myocardium aggravates ischemia-reperfusion injury (IRI) and myocardial infarction. Ischemic preconditioning (IPC) is known to protect the myocardium against IRI. Methods: We evaluated the effects of IPC on myocardium upon which mCRP had been deposited due to IRI in a rat model. Myocardial IRI was induced via ligation of the coronary artery. Direct IPC was applied prior to IRI using multiple short direct occlusions of the coronary artery. CRP was infused intravenously after IRI. The study included sham (n=3), IRI-only (n=5), IRI+CRP (n=9), and IPC+IRI+CRP (n=6) groups. The infarcted area and the area at risk were assessed using Evans blue and 2,3,5-triphenyltetrazolium staining. Additionally, mCRP immunostaining and interleukin-6 (IL-6) mRNA reverse transcription-polymerase chain reaction were performed. Results: In the IRI+CRP group, the infarcted area and the area of mCRP deposition were greater, and the level of IL-6 mRNA expression was higher, than in the IRI-only group. However, in the IPC+IRI+CRP group relative to the IRI+CRP group, the relative areas of infarction (20% vs. 34%, respectively; p=0.079) and mCRP myocardial deposition (21% vs. 44%, respectively; p=0.026) were lower and IL-6 mRNA expression was higher (fold change: 407 vs. 326, respectively; p=0.376), although the difference in IL-6 mRNA expression was not statistically significant. Conclusion: IPC was associated with significantly decreased deposition of mCRP and with increased expression of IL-6 in myocardium damaged by IRI. The net cardioprotective effect of decreased mCRP deposition and increased IL-6 levels should be clarified in a further study.

• 대한한방내과학회지
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• 제18권2호
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• pp.220-228
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• 1997

Background The stenosis of the coronary artery may decrease myocardial oxygen supply and occur myocardial ischemia or infarction. Soojeomsan, one of analgesics is generally regarded to have the effect of vitalizing blood, expelling blood stasis and alleviation cardiac pain. Methods The purpose of this experimental study is to find the influence of Soojeomsan on cardiac enzyme (CPK, Na-K ATPase) of ischemic and reperfused rat hearts which are isolated under the Langendorff apparatus. Ischemia was induced In isolated hearts of Sprague-Dawley rats by ceasing the perfusion for 20 minutes. The experiments were divided into a normal saline orally administered group(control group), a Soojeomsan orally 20ml administered group(sample A) and a Soojeomsan orally 30ml administered group(sample B). The CPK (creatinine phosphokinase) and Na-K ATPase activity of this three group were measured and compared in order to assess the influence of Soojeomsan on protection of isolated rat hearts from ischemia. Results 1. CPK was significantly reduced in Sample A group and Sample B group in comparison with control group in reperfusion(P<0.01), and there were no significant difference between Sample A and B. 2. Na-K ATPase activity was significantly increased in Sample A group and Sample B group in comparison with control group in ischemia(P<0.001), and the activity was significantly higher in Sample B then in Sample A.(P<0.01) 3. There were no significant difference in Na-K ATPase activity of the three groups after reperfusion. Conclusion Soojeomsan has effects to decrease CPK activity and activate Na pump. This result in protection of the myocardium of isolated rat hearts from ischemia.

• The Korean Journal of Physiology and Pharmacology
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• 제28권3호
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• pp.209-217
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• 2024

In addition to cellular damage, ischemia-reperfusion (IR) injury induces substantial damage to the mitochondria and endoplasmic reticulum. In this study, we sought to determine whether impaired mitochondrial function owing to IR could be restored by transplanting mitochondria into the heart under ex vivo IR states. Additionally, we aimed to provide preliminary results to inform therapeutic options for ischemic heart disease (IHD). Healthy mitochondria isolated from autologous gluteus maximus muscle were transplanted into the hearts of Sprague-Dawley rats damaged by IR using the Langendorff system, and the heart rate and oxygen consumption capacity of the mitochondria were measured to confirm whether heart function was restored. In addition, relative expression levels were measured to identify the genes related to IR injury. Mitochondrial oxygen consumption capacity was found to be lower in the IR group than in the group that underwent mitochondrial transplantation after IR injury (p < 0.05), and the control group showed a tendency toward increased oxygen consumption capacity compared with the IR group. Among the genes related to fatty acid metabolism, Cpt1b (p < 0.05) and Fads1 (p < 0.01) showed significant expression in the following order: IR group, IR + transplantation group, and control group. These results suggest that mitochondrial transplantation protects the heart from IR damage and may be feasible as a therapeutic option for IHD.

• Natural Product Sciences
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• 제25권2호
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• pp.136-142
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• 2019

Ischemia/reperfusion-induced myocardial injury is the main cause of acute myocardial infarction. Dendropanax morbifera $L{\acute{e}}veille$ has been used in traditional medicines for the treatment of various diseases such as headache, infectious diseases, and general debility. However, the effect of extract from D. morbifera (EDM) on myocardial ischemic injury is still unknown. In this study, the effects of EDM on neonatal rat cardiomyocytes with hypoxia/reoxygenation (H/R) injury were investigated. The viability of cardiomyocytes with H (30 min)/R (1 h) decreased; however, treatment with EDM significantly inhibited H/R injury-induced cardiomyocyte death. Further, we observed that reactive oxygen species (ROS) generation and intracellular calcium concentration ($Ca^{2+}{_i}$) were significantly reduced in EDM-treated cardiomyocytes compared with that in H/R-injured positive control. In addition, western blotting results showed that EDM attenuated abnormal changes of RyR2 and SERCA2a genes in hypoxic cardiomyocytes. These results suggest that EDM ameliorates ROS generation and $Ca^{2+}{_i}$ homeostasis to prevent dysregulation of calcium regulatory proteins in the heart, thereby exerting cardioprotective effects and reducing hypoxia-induced cardiomyocyte damage, which verifies the potential use of EDM as a new therapeutic agent for the treatment of myocardial ischemic injury.