• The Korean Journal of Physiology and Pharmacology
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• 제14권3호
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• pp.119-125
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• 2010

We investigated the effects of a hot-water extract of Artemisia iwayomogi, a plant belonging to family Compositae, on cardiac ventricular delayed rectifier $K^+$ current ($I_K$) using the patch clamp technique. The carbohydrate fraction AIP1 dose-dependently increased the heart rate with an apparent $EC_{50}$ value of $56.1{\pm}5.5\;{\mu}g/ml$. Application of AIP1 reduced the action potential duration (APD) in concentration-dependent fashion by activating $I_K$ without significantly altering the resting membrane potential ($IC_{50}$ value of $APD_{50}$: $54.80{\pm}2.24$, $IC_{50}$ value of $APD_{90}$: $57.45{\pm}3.47\;{\mu}g/ml$). Based on the results, all experiments were performed with $50\;{\mu}g/ml$ of AIP1. Pre-treatment with the rapidly activating delayed rectifier $K^+$ current ($I_{Kr}$) inhibitor, E-4031 prolonged APD. However, additional application of AIP1 did not reduce APD. The inhibition of slowly activating delayed rectifier $K^+$ current ($I_{Ks}$) by chromanol 293B did not change the effect of AIP1. AIP1 did not significantly affect coronary arterial tone or ion channels, even at the highest concentration of AIP1. In summary, AIP1 reduces APD by activating $I_{Kr}$ but not $I_{Ks}$. These results suggest that the natural product AIP1 may provide an adjunctive therapy of long QT syndrome.

• 동의생리병리학회지
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• 제22권6호
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• pp.1482-1486
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• 2008

The antihypertensive effects of the Wild Mountain Ginseng Cultured Root Extract (WMGCE) were investigated in spontaneously hypertensive rats (SHR). Daily oral administration of the WMGCE (100 and 200 mg/kg) exhibited a significant decrease in blood pressure in SHR rats during for 8 weeks. The systolic blood pressure was dose- and time-dependently decreased significantly from the second weeks (p < 0.05) to the end of WMGCE treatment in SHR. The WMGCE decreased the plasma levels of sodium, potassium, chlorides, urea and osmolarity in SHR rats but no statistically significant change was observed. Furthermore, no significant changes were noted on heart weight, heart rate and diameter of aorta after WMGCE treatment in SHR. Our results suggest that daily oral administration of WMGCE at the dose of 100 and 200 mg/kg for 8 weeks exhibited antihypertensive activities.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.51-65
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• 1990

The purpose of the present study was to examine the hemodynamic responses, especially in arterial and skin blood flows, in conjunction with the changes of plasma catecholamine levels as an indirect marker of adrenergic tone during the early stage of head-down tilt (HDT), and to evaluate the early physiological regulatory mechanism in simulated weightlessness. Ten mongrel dogs, weighing8\;{\sim}\;14\;kg, were intravenously anesthetized with nembutal, and postural changes were performed by using the tilting table. The postural changes were performed in the following order: supine, prone, HDT $(-6^{\circ}C)$ and lastly recovery prone position. The duration of each position was 30 minutes. The measurements were made before, during and after each postural change. The arterial blood flow $({\.{Q}})$ at the left common carotid and right brachial arteries was measured by the electromagnetic flowmeter. Blood pressure (BP) was directly measured by pressure transducer in the left brachial artery. To evaluate the peripheral blood flow, skin blood flow $({\.{Q}})$ was calculated by the percent changes of photoelectric pulse amplitude on the forepaw, and skin temperature was recorded. The peripheral vascular resistance (PR) was calculated by dividing respective mean BP values by ${\.{Q}}$ of both sides of common carotid and brachial arteries. Heart rate (HR), respiratory rate (f) and PH, $Po_{2},\;Pco_{2}$ and hematocrit of arterial and venous blood were also measured. The concentration of plasma epinephrine and norepinephrine was measured by radioenzymatic method. The results are summarized as follows: Tilting to head-down position from prone position, HR was initially increased (p<0.05) and BP was not significantly changed. While ${\.{Q}}$ of the common carotid artery was decreased (p<0.05) and PR through the head was increased, ${\.{Q}}$ of the brachial artery was increased (p<0.05) and PR through forelimbs was decreased. ${\.{Q}}$ of the forepaw was initially increased (p<0.05) and then slightly decreased, on the whole revealing an increasing trend. Plasma norepinephrine was slightly decreased and the epinephrine was slightly increased. f was increased and arterial pH was increased (p<0.05). In conclusion, the central blood pooling during HDT shows an increased HR via Bainbridge reflex and an increased ${\.{Q}}$ of the forepaw and brachial ${\.{Q}}$, due to decreased PR which may be originated from the depressor reflex of cardiopulmonary baroreceptors. It is suggested that the blood flow to the brain was adequately regulated throughout HDT $(-6^{\circ}C)$ in spite of central blood pooling. And it is apparent that the changes of plasma norepinephrine level are inversely proportional to those of ${\.{Q}}$ of the forepaw, and the changes of epinephrine level are paralleled with those of the brachial ${\.{Q}}$.

• Safety and Health at Work
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• 제9권4호
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• pp.468-472
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• 2018

Background: Firefighters are required to use self-contained breathing apparatus (SCBA), which impairs ventilatory mechanics. We hypothesized that firefighters have elevated arterial $CO_2$ when using SCBA. Methods: Firefighters and controls performed a maximal exercise test on a cycle ergometer and two graded exercise tests (GXTs) at 25%, 50%, and 70% of their maximal aerobic power, once with a SCBA facemask and once with protective clothing and full SCBA. Results: Respiratory rate increased more in controls than firefighters. Heart rate increased as a function of oxygen consumption ($V_{O_2}$) more in controls than firefighters. End-tidal $CO_2$ ($ETCO_2$) during the GXTs was not affected by work rate in either group for either condition but was higher in firefighters at all work rates in both GXTs. SCBA increased $ETCO_2$ in controls but not firefighters. Conclusions: The present study showed that when compared to controls, firefighters' hypoventilate during a maximal test and GXT. The hypoventilation resulted in increased $ETCO_2$, and presumably increased arterial $CO_2$, during exertion. It is proposed that firefighters have altered $CO_2$ sensitivity due to voluntary hypoventilation during training and work. Confirmation of low $CO_2$ sensitivity and the consequence of this on performance and long-term health remain to be determined.

• 대한의생명과학회지
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• 제23권3호
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• pp.286-289
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• 2017

This study was designed to clarify the effect of juniper essential oil on the autonomic nervous system. Blood pressure and heart rate variability (HRV) reflecting autonomic nervous system activity were measured. The systolic and diastolic blood pressure were decreased by inhalation of juniper essential oil. High frequency (HF) power level, an indicator of parasympathetic nervous system activity was increased in the stimulation of juniper essential oil. High frequency/low frequency (HF/LF) ratio, an indicator of sympathetic nervous system activity was decreased by the juniper essential oil. These results suggest that juniper essential oil has a modulatory effect on the autonomic nervous system activity.

• The Korean Journal of Physiology
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• 제1권1호
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• pp.103-120
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• 1967

As pointed out by many previous investigators, the cardio-pulmonary system of well trained athletes is so adapted that they can perform a given physical exercise more efficiently as compared to non-trained persons. However, the time course of the development of these cardio-pulmonary adaptations has not been extensively studied in the past. Although the development of these training effects is undoubtedly related to the magnitude of an exercise load which is repeatedly given, it would be practical if one could maintain a good physical fitness with a minimal daily exercise. Hence, the present investigation was undertaken to study the time course of the development of cardio-pulmonary adaptations while a group of non-athletes was subjected to a daily 6 to 10 minutes running exercise for a period of 4 weeks. Six healthy male medical students (22 to 24 years old) were randomly selected as experimental subjects, and were equally divided into two groups (A and B). Both groups were subjected to the same daily running exercise (approximately 1,000 kg-m). 6 days a week for 4 weeks, but the rate of exercise was such that the group A ran on treadmill with 8.6% grade for 10 min daily at a speed of 127 m/min while the group B ran for 6 min at a speed of 200 m/min. In order to assess the effects of these physical trainings on the cardio-pulmonary system, the minute volume, the $O_2$ consumption, the $CO_2$ output and the heart rate were determined weekly while the subject was engaged in a given running exercise on treadmill (8.6% grade and 127 m/min) for a period of 5 min. In addition, the arterial blood pressure, the cardiac output, the acid-base state of arterial blood and the gas composition of arterial blood were also determined every other week in 4 subjects (2 from each group) while they were engaged in exercise on a bicycle ergometer at a rate of approximately 900 kg m/min until exhaustion. The maximal work capacity was also determined by asking the subject to engage in exercise on treadmill and ergometer until exhaustion. For the measurement of minute volume, the expired gas was collected in a Douglas bag. The $O_2$ consumption and the $CO_2$ output were subsequently computed by analysing the expired gas with a Scholander micro gas analyzer. The heart rate was calculated from the R-R interval of ECG tracings recorded by an Offner RS Dynograph. A 19 gauge Cournand needle was inserted into a brachial artery, through which arterial blood samples were taken. A Statham $P_{23}AA$ pressure transducer and a PR-7 Research Recorder were used for recording instantaneous arterial pressure. The cardiac output was measured by indicator (Cardiogreen) dilution method. The results may be summarized as follows: (1) The maximal running time on treadmill increased linearly during the 4 week training period at the end of which it increased by 2.8 to 4.6 times. In general, an increase in the maximal running time was greater when the speed was fixed at a level at which the subject was trained. The mammal exercise time on bicycle ergometer also increased linearly during the training period. (2) In carrying out a given running exercise on treadmill (8.6%grade, 127 m/min), the following changes in cardio·pulmonary functions were observed during the training period: (a) The minute volume as well as the $O_2$ consumption during steady state exercise tended to decrease progressively and showed significant reductions after 3 weeks of training. (b) The $CO_2$ production during steady state exercise showed a significant reduction within 1 week of training. (c) The heart rate during steady state exercise tended to decrease progressively and showed a significant reduction after 2 weeks of training. The reduction of heart rate following a given exercise tended to become faster by training and showed a significant change after 3 weeks. Although the resting heart rate also tended to decrease by training, no significant change was observed. (3) In rallying out a given exercise (900 kg-m/min) on a bicycle ergometer, the following change in cardio-vascular functions were observed during the training period: (3) The systolic blood pressure during steady state exercise was not affected while the diastolic blood Pressure was significantly lowered after 4 weeks of training. The resting diastolic pressure was also significantly lowered by the end of 4 weeks. (b) The cardiac output and the stroke volume during steady state exercise increased maximally within 2 weeks of training. However, the resting cardiac output was not altered while the resting stroke volume tended to increase somewhat by training. (c) The total peripheral resistance during steady state exercise was greatly lowered within 2 weeks of training. The mean circulation time during exorcise was also considerably shortened while the left heart work output during exercise increased significantly within 2 weeks. However, these functions_at rest were not altered by training. (d) Although both pH, $P_{co2}\;and\;(HCO_3-)$ of arterial plasma decreased during exercise, the magnitude of reductions became less by training. On the other hand, the $O_2$ content of arterial blood decreased during exercise before training while it tended to increase slightly after training. There was no significant alteration in these values at rest. These results indicate that cardio-pulmonary adaptations to physical training can be acquired by subjecting non-athletes to brief daily exercise routine for certain period of time. Although the time of appearance of various adaptive phenomena is not identical, it may be stated that one has to engage in daily exercise routine for at least 2 weeks for the development of significant adaptive changes.

• Journal of Nutrition and Health
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• 제33권7호
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• pp.725-732
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• 2000

The purpose of this study was to investigate the effects of green tea catechin on renal dysfunction and blood presure change in chronic cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal group and three cadmium poisoned groups. Cadmium groups were classified to catechin free diet(Cd-0C group) 0.25% catechin diet(Cd-0.25C group) and 0.5% catechin diet(Cd-0.5C group) according to the levels of catechin supplement. Animals were raids for 20weeks. Cadmium were supplied as drinking water of 50ppm Cd2+ Morphological changes shown through a light microscope and an electro-microscope revealed the mitochondria and tubule epithelial cell edema in Cd -0C group but they were alleviated in catechin supplementation. The urinary $\beta$2-microglobulin that measured to observe the glomerular injury were higher in Cd-poisoned groups than in normal group but they was lowered by catechin supplementation. Glomerular filtration ratios(GFR) in Cd-poisoned groups were significantly lower than in normal group but that of catechin supplementation group was similar to normal group. This suggested that catechin protected the kidney from the functional damage. Angiotensin converting enzyme(ACE) activity and blood pressure(BP) in Cd-poisoned groups were significantly higher than in normal group. Heart rate was tended to increase in Cd-poisoned groups. The results indicate that green tea catechin supplementation on chronic cadmium-poisoned rats normalized the renal dysfunction and blood pressure system.

• Toxicological Research
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• 제16권3호
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• pp.211-219
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• 2000

The therapeutic effect of AS2-006A, a derivative of asiaticoside, has been studied and is being developed as a new wound-healing agent. In the present study, the general pharmacological effects on 1) central nervous system, 2) autonomic nervous system, 3) respiratory system, 4) gastrointestinal system. 5) cardiovascular system. and 6) urinary system were assessed in experimental animals and in in vitro models. 1. In vivo animal study: External applications of the 1 % gel ointment of AS2-006A to rats at the doses of 200. 600 or 2000 mg/kg body weight showed no observable pharmacological effects. The effects on the central nervous system were assessed by observation of behavior, hexobarbital-induced sleeping time, pentetrazole-induced convulsion assay, body temperature measurements, and observations on spontaneous activity and catalepsy. The gel ointment exhibited no effects on the cardiovascular system (i.e. blood pressure and heart rate), renal physiology (i.e. urine volume and electrolytes excretion) and gas-trointestinal physiology (i.e. intestinal charcoal propulsion and gastric mucosal irritation). 2. In vitro experiments: The effects of AS2-006A on the physiology of smooth and cardiac muscles were assessed. Muscle contractions were isotonically and isometrically measured in organ chambers using a physiograph. Cumulative additions of AS2-006A (10$^{-9}$ -10$^{-5}$ M) induced no changes in the tension of isolated guinea pig ileum and tracheal muscles. AS2-006A only slightly increased contractility of rat atrial and papillary muscles at 10$^{-2}$ M, which was not statistically different from control. These data showed that the gel ointment of AS2-006A could be externally applied as a wound-healing agent with no potential side effects.

• 대한의용생체공학회:의공학회지
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• 제23권1호
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• pp.73-79
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• 2002

최근 들어 컴퓨터와 디스플레이 기술의 발달로 실제 공포 상황에서의 자극과 거의 유사한 자극을 유발할 수 있는 가상환경의 창조가 가능하게 되었으며 이러한 실제 상황에서의 노출치료 대안으로 가상현실을 이용한 공포증의 치료방법이 사용되어져 왔다. 하지만 가상환경이 공포증 환자 에게 심리적이나 생리적으로 어떠한 영향을 미치는지에 대한 연구는 거의 전무한 실정이다. 따라서 본 논문에서는 가상환경 하에서 공포증환자와 정상인의 생리적 반응에 대한 평가를 함으로써 가상환경이 미치는 영향에 대하여 분석하고. 또한 가상현실 치료 시에 공포증환자의 생리적 반응의 변화를 측정함으로써 치료의 성공유무를 판단할 수 있는 지표를 제시하고자 한다. 본 실험은 스물 두 명의 정상인 (평균 32.74세)과 서른여섯 명의 비행공포증 환자를 대상으로 두 그룹으로 나누어 진행되었다. 생리적 반응으로는 심박동수, 피부저항. 그리고 피부 온도를 측정하였다. 실험결과. 두 그룹에서의 피부저항은 유의한 차이(T(56)=2.978, p〈0.01)를 보였으며, 공포증 환자 그룹 중 가상현실로 공포증이 치료가 된 서른세 명의 피부저항은 치료가 진행됨에 따라 점차 정상인의 특성 쪽으로 가까워짐을 보였다. 본 연구를 통해 생리적 반응. 특히 피부저항은 가상환경에서 피험자의 상태를 이해하거나, 가상환경을 이용한 치료의 결과를 검증하는데 유용하게 사용될 수 있을 것이라 사려된다.

• The Korean Journal of Physiology
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• 제2권2호
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• pp.45-52
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• 1968

Maximal oxygen uptake was measured in twenty-eight middle-aged men aged 45.0 (range: 40.3-50.7) years and fourteen middle-aged women aged 40.5 (range: 34.3-47.5) years by means of a treadmill test. The physique of subjects were:mean skinfold thickness at 4 sites, namely, back, arm, waist and abdomen was 7.59 mm in men and 14.5 mm in women; total body fat estimated from the mean skinfold thickness, 11.9% fat in men and 25.5% fat in women. The detailed observations are as follows: 1. Maximal oxygen uptake expressed on any reference unit in men was greater than that of women. The values of men to women were: 2.61 to 1.92l/min., 45.1 to 37.0 ml/min./kg, 51.8 to 46.5 ml/min./kg lean body mass (LBM), 15.7 to 12.6 ml/min./cm body height. 2. Maximal pulmonary ventilation in men was 80.2 l/min. and 63.5 l/min. in women. 3. There was a correlation of fairly high degree between maximal oxygen uptake and body weight, namely, r=0.56 in men and r=0.79 in women. The correlation between maximal oxygen uptake and lean body mass also was fairly high, namely, r=0.58 in men and r=0.69 in women. 4. The correlation between maximal pulmonary ventilation and body weight or lean body mass was r=0.51 and r=0.25 in middle-aged men and r=0.41 and r=0.19 in middle-aged women, respectively. 5. Maximal heart rate in men was 176.4 beat/min. and it was 183.9 beat/min. in women. 6. Maximal oxygen pulse in men was 14.6 ml/beat and 9.5 ml/beat in women. 7. Aerobic work capacity of korean middle-aged men and women maintained the same level as that of young men and women, respectively, as shown by maximal oxygen uptake expressed ml/min./kg or ml/min./kg lean body mass.