• Journal of Chest Surgery
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• v.34 no.3
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• pp.203-211
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• 2001

배경: AT$_1$수용체의 길항제가 세포 수준에서 심근을 재관류 손사으로부터 보호할수 있다는 것으로 알려져 있지만, 생체내에서의 효과나 그 기전은 아직 명확히 밝혀지지 않았다. 본 연구에서는 백서 심근 허혈 모델을 이용하여, AT$_1$ 수용체의 길항제들 중 하나인 irbesartan이 심근이 재관휴 손상에 미치는 효과를 알아보고, 재관류 손상을 매개하는 한 각지 기전으로서 세포자멸의 기여에 대하여 연구하고자 하였다. 대상 및 방법: Sprague-Dawley 백서에서 무작용 부형약(10% gum arabic: 1군, 개체수=14관) irbesartan(50mg/kg/day :II 군, 개체수=12)을 각각 3일 동안 24시간마다 경구로 투여하였다. 실험동물의 좌 관상 동맥을 45분간 결찰하였다가, 그 후 2시간 동안 재관류시킨 다음 심장을 적출 하였다. TTC(triphenyltetrazolium chloride) 염색법을 이용하여, 허혈 노출 부위에 대한 심근 경색 부위의 비율을 측정하였다. Agarose gel 전기영동상의 DNa 분절 양상과 TUNEL(TdT-mediated dUCP nick end labeling) 염색을 관찰하여 세포자멸이 일어난 정도를 평가하였다. 세포자멸을 조절하는데 관여하는 것으로 알려진 Bcl-2(B-cell lymphoma 2 gene), Bad 등의 단백과 ERK (extracellular signal-regulated kinase), p-38 등 신호전달체계에 작용하는 MAPKs(mitogen-activated protein kinases)의 발현을 측정하기 위하여 Western blot을 시행하였다. 결과: 허혈 노출부위에 대한 심근 경색부위의 비율은 II군(42$\pm$2.7%)이 I군( 64.1$\pm$4.65)에 비해 유의하게 작았다.(p< 0.05), Agarose gel 전기영동상의 DNA laddering 양상은 I군에서 보다 높게 발현되었다. Bad와 ERK2의 발현은 두 군간에 유의한 차이가 없었다. 결론: AT$_1$수용체 길항제인 irbesartan은 생체에서 심근의 재관류 손상을 줄이는 효과가 있었다. 이 효과는 적어도 부분적으로 나만 심근세포의 세포자멸이 감소한 것에 기인한 것으로 설명할 수 있으며, 이 항-세포 자멸 효과는 Bcl-2의 발현증가와 관련이 있는 것으로 추정되었다.

• Journal of Chest Surgery
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• v.33 no.7
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• pp.531-540
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• 2000

Baclgrpimd; Recent studies have suggested that the cardioprotective effect of ischemic preconditioning(IP) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G) is closely related to glycogen depletion and attenuation of intracellular acidosis. In the present study, the authors tested this hypothesis by perfusion isolated rabbit hearts with glucose(G)-free perfusate. Material and Method; Hearts isolated from New Zealand white rabbits(1.5~2.0 kg body weight) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to 45 min global ischemia followed by 120 min reperfusion with IP(IP group, n=13) or without IP(ischemic control group, n=10). IP was induced by single episode of 5 min global ischemia and 10 min reperfusion. In the G-free preconditioned group(n=12), G depletion was induced by perfusionwith G-free Tyrode solution for 5 min and then perfused with G-containing Tyrode solution for 10 min; and 45 min ischemia and 120 min reperfusion. Left ventricular functionincluding developed pressure(LVDP), dP/dt, heart rate, left ventricular end-distolic pressure(LVEDP) and coronary flow (CF) were measured. Myocardial cytosolic and membrane PKC activities were measured by 32P-${\gamma}$-ATP incorporation into PKC-specific peptide and PKC isozymes were analyzed by Western blot with monoclonal antibodies. Infarct size was determined by staining with TTC(tetrazolium salt) and planimetry. Data were analyzed by one-way analysis of variance (ANOVA) and Turkey's post-hoc test. Result ; In comparison with the ischemic control group, IP significantly enhanced functional recovery of the left ventricle; in contrast, functional significantly enhanced functional recovery of the left ventricle; in contrast, functional recovery were not significantly different between the G-free preconditioned and the ischemic control groups. However, the infarct size was significantly reduced by IP or G-free preconditioning(39$\pm$2.7% in the ischemic control, 19$\pm$1.2% in the IP, and 15$\pm$3.9% in the G-free preconditioned, p<0.05). Membrane PKC activities were increased significantly after IP (119%), IP and 45 min ischemia(145%), G-free [recpmdotopmomg (150%), and G-free preconditioning and 45 min ischemia(127%); expression of membrane PKC isozymes, $\alpha$ and $\varepsilon$, tended to be increased after IP or G-free preconditioning. Conclusion; These results suggest that in isolated Langendorff-perfused rabbit heart model, G-free preconditioning (induced by single episode of 5 min G depletion and 10 min repletion) colud not improve post-ischemic contractile dysfunction(after 45-minute global ischemia); however, it has an infarct size-limiting effect.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.1-12
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• 1991

• Proceedings of the KTCVS Conference
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• 1993.06a
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• pp.17-17
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• 1993

• Proceedings of the KTCVS Conference
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• 1996.10a
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• pp.9-9
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• 1996

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.553-558
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• 2010

The purpose of this study was to investigate the effects of premedicated ascorbic acid and hepa-saline irrigation/aspiration on attenuation of ischemia-reperfusion (I/R) injury and recovery of renal function in canine nephrotomy model. In the canine model, nine mixed dogs were subjected to renal nephrotomy with premedicated ascorbic acid and hepa-saline irrigation-aspiration (treatment group 2), and only hepa-saline irrigation-aspiration (treatment group 1). The level of renal function and antioxidant enzymes after nephrotomy were measured. And the expression pattern of TNF-${\alpha}$ and INF-${\gamma}$ was examined in the renal tissue at $7^{th}$ day after nephrotomy. BUN and creatinine levels significantly decreased in the treatment group 1 and 2 compared to that of control group at the $3^{rd}$, 5th and $7^{th}$ day after reperfusion (p < 0.05). And, there was significant difference between treatment group 1 and 2 at the $3^{rd}$ day after reperfusion (p < 0.05). The activities of antioxidant enzymes in plasma was significantly increased in the treatment group 1 and 2 compared to that of control group at the $3^{rd}$, $5^{th}$ and $7^{th}$ day after reperfusion (p < 0.05). And, there was significant difference between treatment group 1 and 2 at the $3^{rd}$ day after reperfusion (p < 0.05). TNF-${\alpha}$ was decreased and INF-${\gamma}$ was increased in treatment groups. The result of this study suggested that irrigation-aspiration has effects on attenuation of renal ischemia-reperfusion injury, and the exogenous ascorbic acid has a role in the attenuation of renal ischemia-reperfusion injury and recovery of renal function in canine nephrotomy model.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.372-376
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• 2012

Acute kidney injury (AKI) is a serious problem associated with high morbidity and mortality. Ischemia-reperfusion is an important cause of acute kidney injury. This study was performed to ascertain clinically useful biomarkers for the diagnosis of AKI. In three miniature pigs, AKI were induced by 60 minutes of bilateral renal ischemia by the clamping renal artery. Blood and urine samples were collected from the pigs prior to clamping (baseline) and 0, 1, 3 and 5 days post-clamping. Serum blood urea nitrogen (BUN), creatinine, sodium and uric acid were measured in serum and urine samples. Fractional excretion of sodium ($FE_{Na}$) and fractional excretion of uric acid ($FE_{UA}$) were calculated. Also, interleukin (IL)-6, IL-18, liver type fatty acid binding protein (L-FABP) and glutathione-S-transferase (GST) were detected by Western immunoblotting. Serum BUN and creatinine levels were increased significantly at day 1 post-clamping in all three miniature pigs. However, $FE_{Na}$ and $FE_{UA}$ showed marked individual differences. Western immunoblotting revealed significantly increased levels of IL-6, IL-18, L-FABP and GST in post-ischemic urine, compared to pre-clamping. While more research concerning the variance of $FE_{Na}$ and $FE_{UA}$ is needed, serum BUN, creatinine, IL-6, IL-18, L-FABP and GST may be sensitive urine biomarkers for diagnosis of AKI together with other biomarkers in the porcine ischemia-reperfusion model.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.94-98
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• 2007

This study was to investigate the effects of ascorbic acid and alpha-tocopherol on the attenuation of renal ischemia-reperfusion (IR) injury in pigs. Ten pigs were subjected to 60 minutes of warm unilateral renal ischemia followed by removal of contralateral kidney and then divided into two groups. Treatment group was performed ascorbic acid and alpha-tocopherol pretreatment 2 days before operation and ascorbic acid with heparin-saline solution irrigation-aspiration. Otherwise, control group used only irrigation-aspiration of heparin-saline solution. Blood samples were collected from these pigs for measurement of serum blood urea nitrogen (BUN) and creatinine values, antioxidant superoxide dismutase (SOD) at pre, day 1, day 3, day 7 and day 14. The kidneys were taken for histopathologic evaluation after euthanasia on postoperative day 14. The levels of BUN were significantly increased in the control group on day 1, day 3 and day 7 (P<0.05). And the level of creatinine was significantly increased in the control group on day 3 (p<0.05). Activity of antioxidant enzymes in plasma revealed significant difference (p<0.05) between control and treatment group at day 14. In histopathologic findings, treatment group was showed less damage than that of control group on the basis of renal tubular damage. It was concluded that ascorbic acid and alpha-tocopherol attenuated renal I/R injury in the pigs.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.593-598
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• 1996

The large number of past investigation on extended myocardial protection clearly indicates that cold potassium cardioplegia and topical cooling have limited capabilities. Accordingly, more recent experimen- tal approaches have focused on the modalities of reperfusion and their implication on postischemic myo- cardial recovery. Oxygen may play a crucial role in the development of ischemic and reperfusion injury. Reactive oxygen radicals may be produced during ischemia or reperfusion after incomplete reduction of molecular oxygen or from other pathway and then induce fatal injury of the heart. The important obser- vation of oxygen-induced myocardial damage during reperfusion has led to the concept of applying oxy- gen free radical scavengers. So, this study is on dietary vitamin C supplementation as antioxidant in rats to determine whether or not they have a higher tolerance against cardiac ischemia-reperf'usion injury under Langendorff system. Male or female Sprague-Dawley rats (190-33Og) were randomly separated into two groups. Group A was not treated(n=10). Group B received vitamin C supplement (n=10). Experiment was performed 24 hours after vitamin C 200mg fed orally as injectable ascorbic acid. There were significant differences in contractile parameters between control and vitamin C-treated group. The RLVP (r te of post/preischemic left ventricular pressure) and Rdp/dt (rate of post/preischemic dp/dt) were significant statistically between two groups (p<0.05). But, RHR (rate of post/preischemic heart rate), time to first beat and sta'utilization were not significant. In conclusion, pretreatment with the antioxidant, ascorbic acid, was found to preserve left ventricular contractile function. But the precise mechanism of action of ascorbic acid has not as yet been determined, so further study will be required.

• Journal of Life Science
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• v.20 no.4
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• pp.555-560
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• 2010

The objective of this study was to investigate levels of serum creatinine, CuSOD and MnSOD protein expression in the kidney after renal ischemic reperfusion with pre-exercise using heat shock protein 70.1 in knock-out mice (KO). The C57/BL6 strain (Wild type: WT) and KO were divided into 4 groups as follows: Sham control group (Sham), pre-exercise group (Ex), pre-exercise +ischemia group (Ex+IR), and ischemia group (IR). CuSOD and MnSOD expression were significantly decreased (p<0.01, p<0.05) and blood creatinine concentration was significantly increased (p<0.01) in the IR group of KO. In contrast, CuSOD and MnSOD expression in the Ex+IR group of KO were higher than the IR group, while creatinine concentration was significantly lower. These results suggest that Hsp70 is directly correlated to renal ischemic reperfusion injury. Pre-exercise in renal ischemia might prevent or inhibit positive oxidative stress inhibitory effects by increasing anti-oxidative enzymes (CuSOD, MnSOD) within the kidney and improve to prevent renal function. Thus, pre-exercise may have a protective role against renal injury after renal ischemia.