• YAKHAK HOEJI
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• v.45 no.6
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• pp.739-745
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• 2001

Of all pesticides, carbamates are known to be most common, since alternatives such as organophosphates have long lifetime and are extremely toxic to produce a delayed neurotoxic effect. Although a number of studies about toxicity of carbofuran, a most widely used carbamate, have been reported, its cardiovascular toxicity has not yet been studied. In the present study, we investigated its cardiovascular toxic effect in anesthetized rat in vivo and in isolated Langendorff rat heart, In anesthetized rat model, carbofuran (10 mg/kg) significantly reduced heart rate, and transiently increased blood pressure. In isolated rat heart, carbofuran (10${\mu}{\textrm}{m}$) caused a significant depression in the left ventricular developed pressure (LVDP), indicating contractile dysfunction by carbofuran. Carbofuran (10${\mu}{\textrm}{m}$) also decreased coronary flow rate (CFR) in isolated heart, indicating carbofuran-induced coronary dysfunction. These results suggest that carbofuran can cause cardiac dysfunction in rat in vivo and vitro.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.231-239
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• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.3
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• pp.89-95
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• 2007

Polygala tenuifolia (PT) is one of the most well-known traditional herbal medicines in Korea which is commonly used for the treatment of cardiovascular symptoms. The anti-ischemic effects of PT in isolated rat heart was investigated by analyzing changes in blood pressure, aortic flow, coronary flow, and cardiac output. And, its underlying mechanism was examined by quantitating intracellular calcium content in rat neonatal cardiomyocytes. Rats were divided into two groups: an ischemia-induced group without any treatment, and an ischemia-induced group treated with PT. Ischemia of isolated heart was induced by stopping the supply of oxygen and buffer for 10 min. The isolated heart was exposed to PT for the first 5 min of 10 min ischemia. PT treatment significantly prevented the decreases of perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, hemodynamics (except heart rate) of the PT-treated group was significantly recovered 60 min after reperfusion compared to the control group (systolic aortic pressure: 83.3% vs. 64.9%, aortic flow volume: 69.5% vs. 48.7%, coronary flow volume: 77.7% vs. 58.4%, and cardiac output: 71.6% vs. 51.2%, p < 0.01). As for the underlying mechanism, PT significantly prevented intracellular calcium increase which was induced by isoproterenol (p < 0.01), suggesting that the anti-ischemic effect of PT is mediated by inhibition of intracellular calcium increase.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.283-293
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• 2009

Ginsenosides, one of the most well-known traditional herbal medicines, are used frequently in Korea for the treatment of cardiovascular symptoms. The effects of ginseng saponin on ischemia-induced isolated rat heart were investigated through analyses of hemodynamic changes including perfusion pressure, aortic flow, coronary flow, and cardiac output. Isolated rat hearts were perfused and then subjected to 30 min of global ischemia followed by 60 min of reperfusion with modified Kreb's Henseleit solution. Myocardial contractile function was continuously recorded. Ginseng saponin administered before inducing ischemia significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output. The ginseng saponin administered group significantly recovered all of the hemodynamic parameters, except heart rate, after ischemia-reperfusion (I/R) compared with ischemia control. The intracellular calcium ($[Ca^{2+}]_i$) content in rat neonatal cardiomyocytes was quantitatively determined. Administration of ginseng saponin significantly prevented $[Ca^{2+}]_i$ increase that had been induced by simulated I/R in vitro (p<0.01) in a dose-dependent manner, suggesting that the cardioprotection of ginseng saponin is mediated by the inhibition of $[Ca^{2+}]_i$ increase. Overall, we found that the administration of ginseng saponin has cardioprotective effects on the isolated rat heart after I/R injury. These results indicate that ginseng saponin has distinct cardioprotective effects in an I/R-induced rat heart.

• Journal of Chest Surgery
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• v.27 no.7
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• pp.563-570
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• 1994

Effect of ischemic preconditioning on left ventricular function after cardiac arrest in isolated rat heart.Ischemic preconditioning reduces infarct size caused by sustained ischemia. However, the effects of preconditioning on post ischemic cardiac function are not well-known. The objective of the present study was to determine whether preconditioning would improve the recovery of left ventricular functions after cardiac arrest in isolated rat heart model.Isolated rat hearts were allowed to equilibrate for 20 minutes and were then subjected to either 5 minutes of global, normothermic transient ischemia [Group 2 and 4] or not [Group 3]. A stabilization period of perfusion lasting 5 minutes after the termination of transient ischemia was followed by a standard global, normothermic 20 minute-ischemia and 35-minute reperfusion challenge [Group 3 and 4]. These following results were odtained.1. The recovery of left ventricular developed pressures showed no significant differences between Group 3 and Group 4 at 50 [P>0.3] and 85 minute [P>0.2].2. Heart rates showed no significant differences throughout all the course of experiment and between groups [P>0.5].3. The recovery of left ventricular maximum dP/dt showed no significant differences between Group 3 and Group 4 at 50 [P>0.1] and 85 minute [P>0.2].4. The recovery of pressure-rate products showed no significant differences between Group3 and Group 4 at 50 [P>0.5] and 85 minute [P>0.1].These results suggest that ischemic preconditioning does not provide significant benefit for the postischemic left ventricular functions in isolated rat hearts.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.88-88
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• 1995

Tetrahydroisoquinoline (THI) compounds have various pharmacological actions in the cardiovascular system. Recently, we have synthesized 1-${\alpha}$-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, YS 49. In the present study, we evaluated the effect of YS-49 on positive inotropic and chronotropic action using isolated rat heart and on blood pressure and heart rate using anesthesized rabbit. Vasodilating action was also assessed in isolated rat thoracic aorta. YS 49, concentration-dependently relaxed rat aorta precontracted with phenylephrine (PE, 0.3 ${\mu}$M) and high potassium (high K$\^$+/, 65.4 mM). The 50% inhibitory concentration (IC$\sub$50/) of YS 49 in PE-induced and high K$\^$+/-induded contraction was 5.36 ${\mu}$M and 2.52 ${\mu}$M, respectively. In isolated rat atria, YS 49 increased both heart rate and force, and in anesthesized rabbit it decreased blood pressure but increased heart rate. In addition, to know the mechanism of action of the compound, propranolol, nonselective ${\beta}$-antagonist, and phentolamine, ${\alpha}$-blocker, were used. Furthermore, a comparison with the effect of higenamine, trimetoquinol on the vasodilating action in rat thoracic aorta was also made. The action of YS 49 was inhibited by the presence of propranolo, not pentolamine. These results indicate that cardiotonic and vasodilatory action of YS 49 is attributable, at least in part, for ${\beta}$-receptor stimulation.

• The Korean Journal of Pharmacology
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• v.8 no.2
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• pp.41-47
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• 1972

Fluorides were supposed to exert a stimulatory action on the catecholamine release. In this study, the authors attempted to investigate the action of sodium fluoride on the catecholamine release from the isolated perfused cow adrenal gland and rat heart. And also the inhibitory effect of sodium fluoride on the monoamine oxidase activity in rat heart and liver mitochondria was investigated. The monoamine oxidase activity was measured by the conversion of benzylamine to benzaldehyde. The results obtained were follows; 1. Sodium fluoride stimulated the release of catecholamine from the isolated perfused cow adrenal gland and rat heart. 2. Sodium fluoride inhibited the rat heart and liver mitochondrial monoamine oxidase activity.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.338-345
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• 1980

We have modified an isolated perfusion rat heart model of cardiopulmonary bypass, with which we are able to screen the effects of various cardioplegic solutions and hypothermia upon the ability of the heart to survivie during and recover from period of ischemic arrest. The modified experimental model was differed from the original as follow : a heat coil chamber of atrial and aortic reservoir provided temperature control, and the perfusate was gassed with each pure oxygen and pure carbon dioxide in 95:5 ratio. The Langendorff perfusion was initiated for a 10 minute period by introducing perfusate at $37^{\circ}C.$ into the aorta from the aortic reservoir located 100 cm above the heart. The isolated perfused working rat heart model was a left heart preparation in which oxygenated perfusion medium (at $37^{\circ}C.$) entered the cannulated left atrium at a pressure of 20 cm $H_{2}O$ and was passed to the ventricle, from which it was sponeously elected(no electrical pacing) via an aortic cannula, against a hydrostatic pressure of 100cm $H_{2}O$. during this working period various indices of cardiac functin were measured. The cardiac functions were stable for over 3 hour with perfusion of Krebs-Henseleit bicarbonate buffer solution containing only glucose (11.1 mM/L). The percentage of cardiac functins were maintained about 94% on heart rate, 80.6% on peak aortic pressure, 87.7% on coronary flow and 76.3% on aortic flow rate after 3 hour of working heart perfusion at a pressure of 20 cm $H_{2}O$. We believe this preparation to be a good biochemical model for the human heart which offers many advantages including economic, speed of preparation, reproducibility, and the ability to handle large numbers.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.268-277
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• 2009

Ginsenosides are among the most well-known traditional herbal medicines frequently used for the treatment of cardiovascular symptoms in South Korea. The anti-ischemic effects of compound K (CK), a metabolite of ginsenoside Rb1, on ischemia-induced isolated rat hearts were investigated through the analyses of the changes in the hemodynamics (blood pressure, aortic flow, coronary flow, and cardiac output) and the measurement of the infarct region. The subjects in this study were divided into four groups: the normal control, the CK-alone group, the ischemia-induced group without any treatment, and the ischemia-induced group treated with CK. No significant differences in perfusion pressure, aortic flow, coronary flow, and cardiac output were found between the groups before ischemia was induced. The oxygen and buffer supply was stopped for 30 min to induce ischemia 60 min after reperfusion in the isolated rat hearts, and the CK was administered 5 min before ischemia induction. The CK treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output under ischemic conditions. In addition, the hemodynamics (except for the heart rate) of the group treated with CK significantly recovered 60 min after reperfusion, unlike in the control group. CK significantly limited the infarct. These results suggest that CK treatment has distinct anti-ischemic effects in an exvivo model of an ischemia-reperfusion-induced rat heart.

• Journal of Chest Surgery
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• v.24 no.5
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• pp.429-437
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• 1991

Beta hydroxytrimethylammonium butyrate[L-carnitine] is highly concentrated in myocardium and it is essential substance for transfer of fatty acids into the mitochondria. We respect that L-carnitine has protective action to myocardium during ischemia. I studied coronary flow and CK - MB isoenzyme of coronary effluent of Langendorff`s isolated rat heart model. As a control group 5 Sprague-Dowley species rat hearts were connected to Langendorff`s isolated rat heart model and perfused for 30 minutes with Kreb-Henseleit buffer solution. After cessation of perfusion for 30 minutes they were reperfused for 30 minutes. In experimental group 10 Sprague-Dowley species rat hearts were perfused with 10mmole /L of L-carnitine contained in Kleb-Henseleit buffer solution. In equilibrium state, coronary flow was 1.7 times greater in experimental group. During reperfusion, both group showed equally decreased flow amount of about 60% of that of equilibrium state. CK-MB isoenzyme level of perfused coronary fluid showed no significant difference in equilibrium state. In reperfusion. CK-MB isoenzyme levels of control group were 17.61$\pm$8. 68U/L at 25 minutes, 23.32$\pm$4.15U /L at 30 minutes; and in experimental group, 13.63$\pm$6. 08U/L at 15 minutes and 13.6$\pm$8.41U /L at 30 minutes respectively. Those values in both states showed significantly lower CK-MB level in experimental group. In conclusion, L-carnitine prevent ischemic myocardial damage during ischemic and reperfusion state of Langendorff`s isolated rat hearts and also I suggest the L-carnitine act potent coronary vasodilator during preischemic and postischemic states of rat hearts.