• Journal of Chest Surgery
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• v.23 no.6
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• pp.1067-1073
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• 1990

To clarify the changes of left ventricular function under normothermia, the time interval between the onset of ischemia and the beginning of contracture of left ventricle[TIC] were recorded in newborn piglet. Myocardial performance was assessed using intraventricular balloon to determine compliance and systolic function after 5 to 10 minutes interval per-fusing normothermic substrate free Krebs solution as a perfusate. The time to onset TIC was 29.5\ulcorner1.7 minutes and peak ischemic contracture was 46.7\ulcorner4.0 minutes[p<0.01]. In myocardial performance, systolic function of left ventricle[defined as cardiac contractility] was kept until 25 minutes of perfusion, but was decreased abruptly after 30 minutes of perfusion[p<0.0018] and diastolic function of left ventricle[defined as diastolic compliance] was kept until 15 minutes of perfusion, but was decreased after 20 minutes of perfusion [p=0.00\ulcorner9]. This study demonstrated maximal time of the tolerance to normothermic global ischemia and functional changes of left ventricle using Krebs perfusate under the same condition.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.357-371
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• 1996

Lithium (Li) is known to be used not only during acute manic psychosis but also acute depressive phase in manic-depression. In the present study, it was attempted to investigate the effect of lithium on catecholamine (CA) secretion from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. Replacement of $Na^+$ (118.4 mM) by lithium in the normal Krebs-bicarbonate solution used to perfuse the gland produced gradually an increased response in the spontaneous catecholamine release, which was peaked at $30{\sim}60$ min after its perfusion. Li-Krebs solution was perfused into an adrenal vein for 2 hours in every experiments. Li-Krebs-evoked CA secretory responses were depressed significantly under loading with $Ca^{++}-free$ medium. This CA secretion evoked by lithium loading was also reduced markedly by the pretreatment with nicardipine ($10^{-6}$ M), TMB-8 ($10^{-5}$ M) and chlorisondamine ($10^{-6}$ M) for 20 min, respectively, while was not affected by preloading with a pirenzepine ($2{\times}10^{-6}$ M)-containing Krebs. $Na^+$ pump inhibition by pretreatment with ouabain ($10^{-4}$ M) for 20 min did make the marked depression in Li-evoked CA secretory responses. Moreover, Li-evoked CA release was also diminished markedly by preloading with tetrodotoxin ($5{\times}10^{-7}$ M)-contaming Krebs for 20 min. All these experimental results taken together suggest that lithium enhances CA secretion in a $Ca^{++}$-dependent fashion by its accumulation in the adrenomedullary chromaffin cells of the rat, and that this secretory effect may be meidated by a dual mechanism: (i) chromaffin cell depolarization and subsequent opening of voltage-sensitive $Ca^{++}$ channels and (ii) activation of a $[Li]_i-[Ca]_0$ counter-transport system.

• The Korean Journal of Pharmacology
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• v.28 no.1
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• pp.41-48
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• 1992

A concentration of 0.01 mM bupivacaine was necessary to maintain approximately 50% depression of contractility of rat atria suspended in a modified Krebs-Ringer bicarbonate glucose medium, pH 7.4 at $30^{\circ}C$. Sodium pyruvate, sodium acetate, and fructose partially restored the contractility of the bupivacaine-depressed atria. However, 20 mM glucose had no effect on the bupivacaine-depressed atria, although this concentration of glucose markedly increased the contractility of normal atria not to be exposed to bupivacaine. Contractility of normal atria was not significantly influenced by sodium pyruvate, sodium acetate, and fructose. The results suggested that at least part of the negative inotropic action of bupivacaine is the result of inhibition of glucose uptake or utilization in the glycolytic pathway, and further pinpoint the blockade as an early step in the glycolytic sequence prior to the phosphofructokinase step.

• The Korean Journal of Pharmacology
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• v.22 no.1 s.38
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• pp.51-59
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• 1986

The effect of metabolic substrate fructose on the force of contraction of isolated rat atria depressed with lidocaine was determined. Fructose produced dose-dependent increase in the force of contraction of isolated atria depressed by substrate-free Krebs-Ringer bicarbonate medium. The maximally effective concentration of fructose was 30 mM. The isolated atria, suspended in Krebs-Ringer bicarbonate glucose medium aerated with 95% $O_2-5%CO_2$at $30^{\circ}C$ and pH 7.4, were depressed 50% by approximately 2.34 mg/100 ml of lidocaine. Addition of 30 mM fructose to these depressed atria resulted in a marked increase in the contractile force similar to that with pyruvate and acetate. Fructose had no significant effect, however, on atria exposed to low-calcium medium. The results are consistent with a previous report suggesting blockade by lidocaine of the uptake or utilization of glucose in the glycolytic pathway, and further pinpoint the blockade as an early step in the glycolytic sequence prior to the phospho-fructokinase step.

• Korean Journal of Pharmacognosy
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• v.13 no.4
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• pp.137-144
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• 1982

It was previously reported from our laboratory that the rate of deterioration of the force of contraction was slower in heart from Panax ginseng extract treated rats. The study carried out to elucidate its mechanism of the action on hearts. The cyclic AMP content in the rat hearts was measured by the method of radioimmunoassay techniques. Panax ginseng extract (100mg/kg/day) was administered orally to male Sprague-Dawley rats weighing 150g to 250g for 1 week and after 24 hrs the hearts were isolated and the cyclic AMP content in the fresh heart was assayed. The difference in cyclic AMP content between the rats treated with Panax ginseng extracts and normal rats was not significant. Panax ginseng extract(l00mg/kg/day) was administered orally to the rats for I week and after 24 hrs the hearts were isolated and perfused with Krebs-Henseleit buffer (pH7.4) for 90min. The cyclic AMP content in the both treated and normal rats was not also significantly different. On the other hand, when total ginseng saponin (50mg/kg/day) was administered orally to rats for 1 week and after 24 hrs, the isolated hearts were perfused with Krebs Henseleit solution for 32min, the cyclic AMP content in total ginseng soponin treated hearts was decreased by 18.7% compared to normal rats. It was also observed that when isolated hearts were perfused with total ginseng saponin $(10^{-4}g/ml)$ for 12 min after 30 min equilibration period, the cyclic AMP content in total ginseng saponin treated hearts was decreased by 23.7% compared to normal rats. Isolated hearts were perfused with ginseng saponins $(10^{-4}g/ml)$ or with Krebs-Henseleit solution alone for 10min and subsequently with dl-isoproterenol $(1/2{\times}10^{-6}M)$ until the positive inotropic effect of isoproterenol was initiated. The cyclic AMP content in each rat hearts treated with total ginseng saponin, or with ginsenoside $Rb_1$, or with Krebs-Henseleit solution alone were increased by 35.5%, 42.4%, 47.5%, respectively, compared to normal rats.

• Bulletin of Korea Environmental Preservation Association
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• v.23 no.9_10
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• pp.48-57
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• 2001

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.108-113
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• 2013

Objectives: Although several cases of lung diseases caused by indium have been reported in Japan, the United States and China, South Korea, which is estimated to have been the world's largest consumer of indium, has not yet established a criteria for the diagnosis of lung diseases caused by indium exposure. In this study, we tried to determine the applicability of the Krebs von den lungen-6, which has been widely recognized for its use with interstitial lung disease in Japan, as a biological exposure index for indium. Methods: Methods: The analysis of indium in serum was conducted by inductively coupled plasma mass spectrometry and the analysis of KL-6 in serum was carried out using enzyme-linked immunosorbent assay kit. Results: The indium levels in serum were distributed from below the detection limit to a peak of $125.78{\mu}g/L$, and the values of the KL-6 were distributed from 104.5 U/mL to 2162.2 U/mL. The serum indium and KL-6 showed good correlation ($R^2$=0.389,pfortrend=0.000) and smoking did not affect the KL-6. Conclusions: The usefulness of KL-6 as a specific biomarker for interstitial lung disease has been recognized. In addition, it is expected that effective prevention of health problems can be achieved by determining the lung-damage progress at an early stage according to individual susceptibility.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.6
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• pp.730-737
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• 2013

The purpose of this study is to investigate vasorelaxant effect of Epimedium koreanum(EK) extract on rabbit carotid artery. In this study, to determine vasorelaxant effect of EK extract on rabbit carotid artery, arterial rings with intact or damaged endothelium were used for experiment using organ bath, and were contracted by norepinephrine(NE). After being contracted, arterial rings were treated with EK extract in a dose-dependent manner To study its mechanism, the contracted arterial rings induced by NE were pretreated with indomethacin(IM), $N_{\omega}$-nitro-L-arginine(L-NNA), methylene blue(MB) or tetraethylammonium chloride(TEA) and 0.1 $mg/m{\ell}$ EK extract was added. To analyze the effect of the EK extract on influx of extracellular calcium chloride($Ca^{2+}$) in rabbit carotid artery, in $Ca^{2+}$-free krebs solution, krebs solution containing 1 mM $Ca^{2+}$ was infused into the contracted arterial ring by NE after pretreatment of EK extract. To measure the cytotoxicity of the EK extract, cell viability of human umbilical vein endothelial cell(HUVEC) was measured by MTT assay, and nitric oxide(NO) was measured by Griess reagent. The EK extract significantly was relaxed the arterial ring with intact endothelium contracted by NE, but the vasorelaxant effect of the EK extract was inhibited in the arterial rings with damaged endothelium. The vasorelaxant effect of the EK extract was not different between the IM-pretreatedand and non-treated arterial rings. The vasorelaxant effect of EK extract were significantly inhibited, when arterial rings were pretreated with L-NNA, TEA, MB. And in $Ca^{2+}$-free krebs solution, increasing of arterial contraction by $Ca^{2+}$ addition were also inhibited by the treatment of EK, but not significant. The treatment of EK extract was increased NO concentration in HUVEC. This study suggested that the vasorelaxant effect of EK extract would be related with EDHF and NO production and increasing of cyclic GMP.

• Polymer(Korea)
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• v.25 no.1
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• pp.108-114
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• 2001

Crosslinked poly(glycerol-co-malate)s were synthesized from L-malic acid in Krebs cycle and glycerol. The synthesized polymer was identified by FT-IR spectroscopy. Swelling degrees of the copolymer hydrogels were increased with an increase in pH of the aqueous solution. Hydrolytic behaviors of the crosslinked copolymers were investigated in various pH buffer solutions at 37${\circ}C$. The Hydrolysis of the copolymers proceeded faster with increasing pH of the aqueous solution. Releasing behaviors of the model drug such as diclofenac monosodium salt were also measured in various pH aqueous solutions at 37${\circ}C$. The release concentration of diclofenac monosodium salt from the hydrogel systems was increased with increasing pH. These facts indicate that the unreacted carboxyl and hydroxyl groups in the copolymers are greatly affected by pH in the conditions.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.217-223
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• 1998

Oxygen-derived free radicals have been implicated in many important functions in the biological system. Electrical field stimulation (EFS) causes arterial relaxation in animal models. We found that EFS applied to neither muscle nor nerve but to Krebs solution caused a relaxation of rat aorta that had been contracted with phenylephrine. In the present study, therefore, we investigated the characteristics of this EIRF (electrolysis-induced relaxing factor) using rat isolated aorta. Results indicated that EIRF acts irrespective of the presence of endothelium. EIRF shows positive Griess reaction and is diffusible and quite stable. EIRF-induced relaxation was stronger on PE-contracted aorta than on KCl-contracted one, and inhibited by the pretreatment with methylene blue. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, potentiated the EIRF-induced relaxation. $N^G-nitro-L-arginine$, NO synthase inhibitor, did not inhibit the EIRF-induced relaxation. Deferroxamine, but not ascorbic acid, DMSO potentiated the EIRF-induced relaxation. These results indicate that electrolysis of Krebs solution produces a factor that relaxes vascular smooth muscle via cGMP-mediated mechanism.