• 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.

• Journal of Chest Surgery
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• v.27 no.7
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• pp.571-575
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• 1994

The hemodynamic effects of thyroid hormone are well established, and this hormone affects myocardial contractility, heart rate, and myocardial oxygen consumption. But the role of cardiopulmonary bypass on the thyroid function is not yet fully understood. We have studied twelve patients [male and female patients were equal in number] who were performed open heart surgery under cardiopulmonary bypass. The results are followed. 1] The serum level of T3 began to fall after cardiopulmonary bypass and sustained significantly till 24 hours after operation[p<0.05] 2] The concentrations of T4, Free T4, and TSH were slightly decreased after cardiopulmonary bypass but was maintained within normal range. 3] This above findings are similar to the "sick sinus syndrome" that is seen in severely ill patient. 4] We can propose that T3 would be effective in postoperative low cardiac output syndrome. syndrome.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.199-209
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• 1993

The effects of ${\alpha}_1$-adrenergic stimulation on membrane potential, intracellular sodium activity $(a_N{^i{_a}})$, and contractility were investigated in the isolated papillary muscle of euthyroid, hyperthyroid, and hypothyroid guinea pigs. Cardiac alterations in the thyroid state have been shown to induce marked changes in action potential characteristics, the most pronounced shortening of action potential duration by hyperthyroidism and an increase in duration by hypothyroidism. $10^{-5}M$ Phenylephrine produced a decrease in $(a_N{^i{_a}})$ in euthyroid and hypothyroid preparations, but an increase in $(a_N{^i{_a}})$ in hyperthyroid ones. The major findings were that phenylephrine produced a stronger positive inotropic effect(PIE) without initial negative inotropic effect(NIE) in hyperthyroid preparations, while phenylephrine produced markedly NIE in hypothyroid ones. The alterations in membrane potential, $(a_N{^i{_a}})$, and contractility were abolished by $3{\times}10^{-5}M$ prazosin in hypothyroidism. In hypothyroid ventricular muscle, the decrease in $(a_N{^i{_a}})$ caused by phenylephrine were not abolished or reduced by $10^{-5}M$ strophanthidin, $10^{-5}M$ TTX, $3{\times}10^{-4}M$ lidocaine, or $100^{-5}M$ verapamil. These results indicate that the ${\alpha}_1$-adrenoceptor-mediated decrease in $(a_N{^i{_a}})$ is not associated with a stimulation of the $Na^+$-$K^+$ pump, inhibition of the $Na^+$ or $Ca^+$ channel in hypothyroid ventricular muscle. $10^{-5}M$ Phenylephrine decreased $(a_N{^i{_a}})$ but increased $(a_N{^i{_a}})$ in the presence of a PKC activator phorbol dibutyrate$(PDB_u)$. In conclusion, it is suggested that the following sequence of events in response to phenyleplhane occur in guinea pig ventricular muscle. First, changes in thyroid state may contribute to the ventacular electrophysiological propeties or ion transport system. Second, the adrenoceptor-mediated initial transient NIE may be associated with the decrease in $(a_N{^i{_a}})$ by PKC activation.

• Biomolecules & Therapeutics
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• v.20 no.4
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• pp.386-392
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• 2012

The endothelin (ET) signaling pathway controls many physiological processes in myocardium and often becomes upregulated in heart diseases. The aim of the present study was to investigate the effects of ET receptor upregulation on the contractile function of adult ventricular myocytes. Primary cultured adult rat ventricular myocytes were used as a model system of ET receptor overexpression in the heart. Endothelin receptor type A ($ET_A$) or type B ($ET_B$) was overexpressed by Adenoviral infection, and the twitch responses of infected ventricular myocytes were measured after ET-1 stimulation. Overexpression of $ET_A$ exaggerated positive inotropic effect (PIE) and diastolic shortening of ET-1, and induced a new twitch response including twitch broadening. On the contrary, overexpression of $ET_B$ increased PIE of ET-1, but did not affect other two twitch responses. Control myocytes expressing endogenous receptors showed a parallel increase in twitch amplitude and systolic $Ca^{2+}$ in response to ET-1. However, intracellular $Ca^{2+}$ did not change in proportion to the changes in contractility in myocytes overexpressing $ET_A$. Overexpression of $ET_A$ enhanced both systolic and diastolic contractility without parallel changes in $Ca^{2+}$. Differential regulation of this nature indicates that upregulation of $ET_A$ may contribute to diastolic myocardial dysfunction by selectively targeting myofilament proteins that regulate resting cell length, twitch duration and responsiveness to prevailing $Ca^{2+}$.

• The Korean Journal of Pharmacology
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• v.10 no.2
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• pp.43-54
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• 1974

The cactus family Cactaceae, numbering about 1,500 species, is a fleshy-stemmed perennial plant which is principally distributed in the south and north America. On the other hand, the cactus plant is presumed to be introduced into Korea in 1912-1945, thereafter it has been cultivated merely in favor of ornamentation with the exception of being occasionally used as medication among laymen. Opuntia elata which belongs to Opuntia genus, the Cactaceae family is one of the cacti being cultivated a great deal in Korea. Cho et. al. reported in 1974 that Opuntia dilenii manifested the cardiac inhibitory effect and oxytocic effect, and its mechanism might be partially due to the direct action. Besides this, there are few reports on the pharmacological research concerning Opuntia genus to be demonstrated in Korea. However, some other cacti have the remarkable pharmacological effects; the active ingredients, mescaline, anhalamine, anhalanine, etc. from Peyote cactus (Lophophora williamsii) belonging to Lophophora genus have the psychotomimetic and sympathomimetic effects, and the cardioactive glycosides from Cactus Grandifolius (Selenicereus grandiflorus) belonging to Cereus genus have the cardioactive and diuretic effects. The authors hereby inquired into this study to find out the propriety of the pharmacological properties of the ethanol extract of Opuntia elata (EX) on the heart, blood pressure, respiration, intestine and uterus in the experimental animals. The results of the experiment were as follows: 1. Administration of EX manifested the cardiac inhibitory effect caused by the negative inotropic action in the isolated heart of frog, and the pretreatment of atropine did not affect the inhibitory effect produced by EX. 2. Administration of EX manifested the transient hypotensive effect in the intact rabbit, and the pretreatment of atropine did not affect the hypotensive effect produced by EX. 3. Administration of the small dose of EX manifested no significant effect, but moderate dose or more the stimulating effect, and the large dose the asphyxia on the respiratory motility in the intact rabbit. 4. Administration of EX manifested the sustained augmentation of contractility in the excised duodenum of rabbit, and the pretreatment of atropine did not affect the stimulating effect produced by EX. 5. Administration of EX manifested the sustained augmentation of contractility in the excised pregnant uterus of rabbit, and the pretreatment of atropine and oxytocin did not affect the oxytocic effect produced by EX, but that of barium chloride more or less stimulated the oxytocic effect produced by EX.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.23-29
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• 1976

Aconiti tuber butanol fraction has been recently known to have stimulatory effect on myocardial contractility. In the present study, the possibility that the Aconiti tuber butanol fraction acts directly on contractile proteins of myocardium has been investigated using natural actomyosin extracted from dog heart. It revealed that Aconiti tuber butanol fraction in concentrations from $10^{-2}{\sim}10^{-7}\;gm/ml$ had no stimulatory effect on either the $Mg^{++}$ or $Ca^{++}$-activated adenosinetriphosphatase activity of cardiac actomyosin. And no direct $Ca^{++}$-like action of the drug on cardiac actomyosin was also found. Aconiti tuber butanol fraction in concentrations above $10^{-4}\;gm/ml$, however, was somewhat stimulatory on superprecipitation of actomyosin and markedly inhibited the membrane bound $Na^+-K^+$-activated ATPase activity. In these connections, the positive inotropic action of Aconiti tuber butanol fraction on myocardium thus does not seem to reflect a direct interaction with contractile proteins, but the drug seem to stimulate myocardial contractility through the actions on the membrane transport of $Ca^{++}$.

• The Korean Journal of Nuclear Medicine
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• v.19 no.2
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• pp.43-50
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• 1985

With the improvement of hemodialysis, the course of the disease in patient with endstage renal disease has been clearly improved. Nevertheless, among several shortcomings to our present mode of renal replacement therapy, cardiovascular complications have been the leading cause of morbidity and mortality. Several factors such as anemia, arteriovenous shunting of blood, intermittent extracorporeal circulation and hypertension may be contributing. But little is known about the quantitative cardiac hemodynamic characteristics occurred during hemodialysis. The purpose of this study is to observe the sequential hemodynamic changes before, during and after the hemodialysis and to investigate reliable parameters in the detection of ventricular dysfunction. In the present study, equilibrium radionuclide cardiac angiography was performed and left and right ventricular volume indices, ejection phase indices of both ventricular, performance were measured in the 16 stable patients with chronic renal failure treated with maintenance hemodialysis sequentially i.e. before, during (early and late phase) and after the hemodialysis. The results obtained were as follows; 1) The indices of the left ventricular function were not changed during the hemodialysis but increased after the hemodialysis. 2) The indices of the right ventricular function(EF, SVI) were significantly decreased in the early phase (15, 30 minutes after starting extracorporeal circulation) but recovered after the hemodialysis. 3) The ratio of right ventricular to left ventricular ejection fraction was significantly decreased in the early phase and the lung volume indices were significantly increased at the same phase. As a conclusion, hemodialysis improves left ventricular function maybe due to increased contractility, and effects on the right ventricular function maybe due to the increased lung volume in the early phase of hemodialysis.

• 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.

• CELLMED
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• v.8 no.3
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• pp.14.1-14.6
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• 2018

Santalum album Linn. [Family: Santalaceae] is commonly known as white sandalwood, sandal safaid and safed chandan. It is one of the most valuable trees and second costliest wood in the world. Sandalwood and its oil is extensively used in the Unani and other traditional systems of medicine as it has blood purifier, anti-inflammatory, analgesic, exhilarant, cardiotonic, antiseptic, nervine tonic and expectorant properties. It is used in skin, cardiac, liver, gastrointestinal, respiratory, integument and urogenital disorders. These uses are supported and proven by many in vitro or in vivo studies. The proven pharmacological activities of S. album are antimicrobial, anti-oxidant, anti-inflammatory, antimutagenic and anti-fatigue. The research has proven that sandal oil or its constituents have anti-microbial activity. Sandalwood oil showed skin cancer preventive effect in mice and its constituent alpha santalol showed the anticancer property. The methanolic extract of wood was confirmed for antioxidant, free radical scavenging, analgesic and anti-inflammatory activities. ${\alpha}$ and ${\beta}$ santalols present in sandal oil showed sedative effects. Sandalwood tea had a significant effect on heart muscles of frog and showed increased myocardial contractility. Its oil showed significant changes in hepatic xenobiotic metabolizing enzymes. Sandalwood oil and its major constituents showed less acute oral and dermal toxicity in laboratory animals. Hence, the aforementioned studies justify the uses of sandalwood and its oil mentioned in the classical Unani literature. However, further clinical trials are suggested to confirm its efficacy and safety in humans.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.311-317
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• 2001

In this work we have investigated the physiological effects of $MgCl_2$ in isolated atrium, papillary muscle, perfused heart and anesthesized guinea pig, The addition or infusion of $MgCl_2$ (0~20 mM or mg/kg) to perfused hearts and to anesthesized guinea pigs induced a marked and dose-dependent negative chronotropic effect. The sinoatrial node automaticity could also be reduced by $MgCl_2$. The addition of $MgCl_2$to isolated atria and to papillary muscles induced a marked and dose-dependent negative inotropic effect. The threshold voltage could be increased by $MgCl_2$in papillary muscle. Increasing $MgCl_2$ shortened the action potential duration (APD) in dose-dependent manner at 30% ($APD_{30}$) and 90% repolarization ($APD_{90}$) measured with conventional microelectrode technique in papillary muscle. In anesthesized guinea pig, the magnesium infusion resulted in a dose-dependent drop in blood pressure. These results suggested that magnesium is closely associated with cardiac physiological condition and exerts antiarrhythmic activities.