• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.231-236
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• 1999

This study was performed to examine 1) Whether hypothermic cardiac arrest produces myocardial HSP72 expression; 2) And if, whether it serves to protect the heart against the subsequent hypothermic arrest. In the present study, neonatal rats were placed in an icebath to induce hypothermia. To determine whether hypothermic cardiac arrest produces myocardial HSP72, experimental animals were subjected to 10-min hypothermic insult before the extraction of the heart. The intervals between the insult and extraction were 1 (1 HR), 4 (4 HR), 8 (8 HR), 24 (24 HR) or 72 (72HR) hours. A minimal amount of HSP72 was detected in control, 1 HR and 72 HR groups. In contrast, 8 HR and 24 HR groups showed a significant level of HSP72 expressions. To assess the cardioprotective effect of HSP72 against hypothermic cardiac arrest, we compared the proportion of recovery from the arrest between control and preconditioned (PREC) animals. Control animals were subjected to 20-min hypothermic insult, while PREC group was preconditioned by 10-min hypothermic insult 8 hours before the 20-min test hypothermic insult. Resuscitation rate from cardiac arrest induced by the 20-min hypothermic insult in PREC group was significantly higher than that in controls. These results suggest that the cardioprotective effect of hypothermic preconditioning is associated with an increase in HSP72 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.4
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• pp.383-391
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• 1999

This study was carried out to determine whether the effects of an ${\alpha}_2-adrenoceptor$ agonist, clonidine, on mean arterial pressure (MAP) and heart rate (HR) are influenced by mild hypothermia. Experiments were performed in respiration-controlled and spontaneously breathing pentobarbital-anesthetized rats. Rectal temperature was maintained at $37.5{\pm}0.3^{circ}C$ for normothermic groups or at $35.2{\pm}0.3^{circ}C$ for mild hypothermic groups. Intravenous injection of clonidine (1 and 2 ${\mu}g/kg)$ produced depressor and bradycardic responses in spontaneously breathing rats under both normothermic and mild hypothermic condition: a decrease in MAP was not altered but bradycardic response was significantly augmented in the mild hypothermic group as compared with the normothermic group. Under the respiration-controlled condition, the hypotensive effect of clonidine $(2\;{\mu}g/kg)$ was reduced, whereas the bradycardic effect was increased in mild hypothermic rats as compared with normothermic rats. Both hypotensive and bradycardic effects of clondine $(2\;{\mu}g/kg)$ were blocked by pretreatment with an ${\alpha}_2-adrenoceptor$ antagonist, yohimbine (0.5 mg/kg), in both thermal conditions. Yohimbine (0.5 mg/kg, i.v.) alone produced signifcantly an increase in heart rate in the mild hypothermic group than in the normothermic group. Pretreatment with a muscarinic receptor antagonist, atropine methylnitrate (1 mg/kg, i.v.), attenuated the bradycardic effect of clonidine in the mild hypothermic group but not in the normothermic group. These results suggest that clonidine- induced bradycardia is amplified by mild hypothermia probably through an increased parasympathetic activity.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.732-739
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• 1985

This study was experimentally undertaken to evaluate the effect of the coronary vasodilator-mixed cardioplegic solution on myocardial protection during prolonged aortic cross-clamping. The dogs were divided into two groups: control group A[received hypothermic cardioplegic solution without any additive coronary vasodilator], and comparing group 8[received hypothermic cardioplegic solution, mixed with various coronary vasodilators and Inderal]. Group A further was divided into two subgroups: subgroup A-1[ischemic time, 90 minutes], and subgroup A-2 [ischemic time, 240 minutes]. Group B further was divided into five subgroups: subgroup B-1 [received papaverine mixed hypothermic cardioplegic solution], subgroup B-2[received nitroglycerin mixed hypothermic cardioplegic solution], subgroup B-3 [received nitroprusside mixed hypothermic cardioplegic solution, subgroup B-4[received hydralazine mixed hypothermic cardioplegic solution], and subgroup B-5 [received inderal mixed hypothermic cardioplegic solution]. The specimens from all of the subgroups were studied by electron microscopic examination. The specimens of subgroups [B-l, B-2 8-3, and B-4], received coronary vasodilators mixed hypothermic cardioplegic solutions, were also compared by methylene blue induced staining of the myocardium and coronary vessels. The results obtained were as followings: l. On electron microscopic examination, all of the specimens, including subgroup A-2, showed no irreversible change of the myocardium. But the best result was obtained from the subgroup B-l, treated by papaverine mixed hypothermic cardioplegic solution. The subgroup B-2, treated by nitroglycerin, was next. And the subgroup B-5, treated by Inderal, was agreeable, comparing the electron microscopic finding with control group in the effect of myocardial protection. 2. The distribution in the myocardium of cardioplegic solution was demonstrated with the aid of methylene blue staining in the subgroups of B-l, B-2, B-3, and B-4, and they were the groups treated by papaverine, nitroglycerin, nitroprusside, and hydralazine in their grouping order. The best result was obtained from the subgroup B-1 [papaverine]. The subgroup B-2 [nitroglycerin] was next. The subgroup B-3 [nitroprusside] was moderate in finding of the colorization. The subgroup B-4 [hydralazine] was the poorest in the distribution of the cardioplegic solution in the myocardium. From these results, it appeared that myocardial protection during ischemic arrest for open heart surgery could be enhanced considerably when coronary dilatation was assured.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.1
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• pp.23-33
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• 2007

It has been reported high concentrations of zinc and taurine in ocular tissue, especially the retina-choroid, and the presence of physiological levels of zinc and taurine in these tissues seem essential for their normal function. In addition, several studies have reported temperature as another effector to the visual sensitivity. But, in spite of many studies, there are still remained many questions about their function and correlation in visual adaptation system. The purpose of present study was to clarify these points using electroretinogram(ERG) recording and absorption spectra scanning, before and after zinc and taurine treatments and hypothermic-effect in bullfrog(Rana catesbeiana) which is one of the poikilothermal animal. The optimal zinc concentration used in this study was determined $10^{-4}M$ while the optimal taurine concentration was 10-5 M, and temperature change for hypothermic-effect went through '$25^{\circ}C {\rightarrow}0^{\circ}C{\rightarrow}25^{\circ}C$'. In ERG recording, it is obtained that dark-adapted threshold became elevated and b-wave amplitudes was increased with zinc and taurine treatment and hypothermic-effect. In absorption spectra scanning, there is distinct absorbance increment over the whole spectral range(400~750 nm) after zinc and taurine treatment and hypothermic-effect. Furthermore there are some synergism effects between zinc and taurine as well as between zinc and hypothermic-effect as a result of co-treatment, respectively.

• Archives of Pharmacal Research
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• v.18 no.1
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• pp.38-40
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• 1995

melandrin exhibited an analgesic activity as assessed by inhibition of writhing syndromein mice and by pressure method of inflamed paws of arts and inflamed tails of mmice, and showed a hypothermic effect. However, no anti-inflammatory activity was shown.

• Journal of Pharmaceutical Investigation
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• v.16 no.1
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• pp.24-30
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• 1986

Ssangwhatang which has been known to have antipyretic, analgesic and antifatigue effects are composed of Paeoniae Radix, Angelicae gigantis Radix, Astragali Radix, Rehmaniae Radix, Cnidii Rhizoma, Cassiae Cortex, Glycyrrhizae Radix and Puerariae Radix. Effects of some formulations of Ssangwhatang were studied with respect to the analgesic, antipyretic, hypothermic, anticonvulsive and antiinflammatory actions in experimental animals. The results obtained were as follows: 1) Prescription A, B, C and D of Ssangwhatang were showed significant analgesic effect by the acetic acid stimulating method in mice. 2) All Ssangwhatang-prescriptions used in this studies had hypothermic effect in normal mice. 3) Significant antipyretic effect in febrile rabbits were recognized in prescription A and C of Ssangwhatang, while not in prescription B and D of Ssangwhatang. 4) Prescription A, B, C and D of Ssangwhatang showed marked antiinflammatory effect against the edema induced by carrageenin in rats. 5) Prescriptions of Ssangwhatang did not show significant anticonvulsive effect against the convulsion induced by picrotoxin and strychnine in mice. From the above results, analgesic, hypothermic, antipyretic and antiinflammatory effects were recognized in Ssangwhatang. Ssangwhatang A- and C- prescriptions added with Pueraiae Radix showed better effects than prescription B and C of Ssangwhatang.

• The Korean Journal of Pharmacology
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• v.13 no.1 s.21
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• pp.7-12
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• 1977

Recently several reports have claimed that the bath temperature changes, such as lower bath temperature, produce supersensitivity on the positive chronotropic effect of catecholamine in cat, mouse and guinea pig atria. However, others showed controversial results against temperature-dependent supersensitivity. Similarly, the inotropic effect of ouabain is diminished in febrile state, however some investigators indicated that cardiac glycoside showed less toxicities and less effects in hypothermic condition. In this study, the effects of norepinephrine and epinephrine on inotropy and chronotropy in isolated rat atria was investigated by changing the temperature of bath ($30^{\circ}C$, $^35{\circ}C$ and $38^{\circ}C$). In addition, the effects of ouabain on atria in hypothermic bath was also studied. The followings are the results. 1. At the lower bath temperature isolated rat atrial rate was decreased and contractility was increased. 2. The chronotropic responses to norepinephrine and epinephrine in $38^{\circ}C$ were decreased when the bath temperature lowered to $35^{\circ}C$ or $30^{\circ}C$, while the inotropic responses were not affected. 3. Hypothermic supersensitivity to norepinephrine or epinephrine was not observed in rat atrium. 4. The inotropic response to ouabain was potentiated but chronotropic response was diminished by a lowering in the bath temperature. In conclusion, the chronotropic response of rat atrium to catecholamine was decreased, however, hypothermic supersensitivity was no longer present in rat atrium and the inotropic response of ouabain was increased at lower bath temperature.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.759-770
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• 1985

This study was experimentally undertaken to evaluate the effect of hypothermic oxygenated cardioplegic solution on myocardial protection during prolonged aortic cross clamping under cardiopulmonary bypass. Dogs were divided into two groups control group [received hypothermic unoxygenated cardioplegic solution] and experimental group [received hypothermic oxygenated cardioplegic solution]. Coronary sinus effluent was obtained at once and 30, 60, 90 minutes after cross-clamping for the determination of pH, PCO2,PO2 and lactate level during the infusion of cardioplegic solution and myocardial biopsies were obtained after cessation of 90 minutes of aortic cross-clamping. The results obtained were as follows: 1. There was no significant differences in the pH and PCO2 between the oxygenated and unoxygenated cardioplegic solution but the PO2 of the oxygenated solution was 4 times greater than unoxygenated solution, and also the oxygenated solution had a significantly greater oxygen content [2.020.05 ml 02/min] and had much more oxygen delivery than unoxygenated solution. 2. The myocardial oxygen consumption and the myocardial oxygen extraction in oxygenated group were 1.63 ml 02/100 ml and 67.32% respectively, which was greater than those in unoxygenated group. 3. Regarding to pH and PCO2 of coronary sinus effluent, there was no significant differences between two groups in early period of infusion of cardioplegic solution, but the pH shifted to acidosis from 60 minutes, PCO2 increased from 90 minutes of aortic cross-clamping, and PO2 markedly decreased from 90 minutes of aortic cross-clamping in unoxygenated group. 4. The lactate concentration of coronary sinus effluent revealed relatively normal in both groups, but showed slight increase up to 27.54.56 mg/100 ml at 90 minutes of aortic cross-clamping in unoxygenated group. 5. On electron microscopic study, the ultrastructural integrity of myocardial cells in oxygenated group was well preserved within 90 minutes. Slight swelling and deformity of mitochondria, interfibrillar widening, and disarrangement of myofibrils were observed at 90 minutes after aortic cross-clamping in unoxygenated group. From these results, the use of hypothermic oxygenated cardioplegic solution seemed to be effective and better method for the preservation of ischemic myocardium during the prolonged aortic cross-clamping.

• Journal of Chest Surgery
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• v.2 no.1
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• pp.105-114
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• 1969

This experiment was carried out to study the responses of cellular component of blood and bone marrow to cold and also the changes of coagulation during cooling. Forty-two mongrel dogs were subjected to hypothermia by ice-water surface cooling technique. Lowest body temperature ranged from 21-23 degree. Dogs were divided into 3 groups,Group I, 12 dogs: pentothal anesthesia for 3 hours, Group II, 20 dogs;hypothermic group and Group III,10 dogs;postsplenectomy hypothermic group. Results were summarized as follows: 1. Hemoglobin, hematocrit and red blood cell count significantly increased when animals were cooled, and increase was noted in similar magnitude among the animals of Group I. 2. White blood cell count extremely decreased after cooling and effect of splenectomy on white blood cell count was not apparent. No significant changes were seen among Group I. 3. Differential count of white blood cell when cooled showed relative increase of polymorphonuclear neutrophil and decrease of lymphocyte. 4. There was marked decrease of platelets when body temperature reached to 21-23degree and essentially. no changes was noted in Group I. 5. Clotting time, bleeding time, plasma prothrombin time, recalcification time, and fibrinolysis showed no significant changes when dogs were cooled. Clot retration and prothrombin consumption during hypothermia appeared to be poor. In Group II, bleeding time decreased after splenctomy and when body temperature was lowered, plasma prothrombin time, clot retraction, and prothrombin consumption decreased. Decreased bleeding time and poor clot retraction were noted in Group I. 6. It was found that megacaryocyte count decreased even though platelet count of peripheral blood markedly diminsished when animals were cooled. There was some tendency of erythroid hyperplasia noted during hypothermia.

• Journal of Chest Surgery
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• v.7 no.2
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• pp.145-152
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• 1974

The effect of reticuloendothelial hyperfunction on hypothermic preservation of lung was studied in dogs. In order to evaluate the viability after hemodynamic_ load in preserved isolated lung, observations were made on the rate of increase in weight, degree of edema,compliance and surface activity of lung. The results obtained as follows: l. In the group of activating of the reticuloendothelial system by injection of sodium thiosulfate intravenously before pneumonectomy and infusion of naphthionine through the pulmonary artery before hypothermic preservation of isolated lung the limit of preservation was eight hours whereas four hours in non-treated control group. 2.Therefore the method of activating of the reticuloendothelial system before and after pulmonary resection seems effective in preserving for prolonging the period of preservation of lung by means of inhibition of pulmonary edema. 3. Pulmonary surface activity is expected to be valuable as a method in evaluation of the viability of preserved lung along with compliance and rate of increase in weight of lung.