집토끼 동방결절의 활동전압에 미치는 Vanadate의 효과

조용문,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.3

In order to investigate the electrphysiological effect of vanadate, a potent inhibitor of Na^+-K^+ pump, on the cardiac muscle, the alteration of transmembrane potential as influenced by the drug was measured in rabbit SA rodes in vitro by means of KCI glass intracellular microelectrodes. The followings were results of findings: 1. The rate of spontaneous firing was decreased in the presence of vanadate and the maximum inhibition which was about 50% of contral level was obtained at drug concentrations of 10^-3 M or higher. 2. The maximum diastolic potential(M.D.P.) was depressed by vanadate in a dose-dependent manner and the maximum inhibitory effect was obtained at the drug concentration of 10^-3 M. However the peripheral pacemaker cells were more resistant to the drug effect than the central pacemaker cells at lower concentrations of the drug. 3. In both central and perepheral pacemaker cells, vanadate had no effect on the M.D.P. in concentrations up to 5×10^-4 M. However on at 5×10^-2 M, the drug depressed the M.D.P. in the peripheral cells. 4. Changes of the action potential induced by vanadate were qualitatively similar to those occuring when the calcium concentration of the bathing medium was raised to 4mM. These results may be interpreted as that vanadate increases the rate of Ca^++ influx info the cell in S-A nodes.

신부전환자에 있어서의 혈청이온화된 칼슘의 측정

박한철,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.1

1. With glass microelectrode technique specific for calcium ion, measurements were made for serum ionized calcium. The calibration curve was linear for pCa(2-4) and the tests were reproducible. 2. For five persons each with normal health and with uremia, serum creatinine above 10㎎/㎗, ionized calcium, total calcium, total protein, albumin, and inorganic phosphate were measured in the sera. The results are as following: 1) There were significant differences in serum phosphate and ionized calcium levels between healthy group and uremic patients. The differences were not significant in total calcium, total protein, and albumin contents. 2) The values of ionized calcium, total calcium, total protein and albumin were scattered, but individually some with uremia had lower values. 3. Preliminary tests for ionized calcium assay gave the experience that the ways of collecting and storing samples would alter the data significantly. 4. It is, therefore, felt that further studies on simplification of the sample handing before the measurement of ionized calcium is desirable.

Oualbain과 Verapamil이 심근칼슘저장고에 미치는 영향

김병국,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1981 中央醫大誌 Vol.6 No.1

The control isometric contraction of rabbit papillary muscle preparations were recorded by the stimulation 'frequency of 1 Hz. and priming stimulation were applied to activate the intracellular calcium by the stimulation frequency of 5 Hz. for 5 seconds. After the resting period, the amplitudes of contraction, were compared with that of control and the ratios were plotted with respect to time in a semi-log paper. The experiments were performed in a control Tyrode solution, high calcium solution, ouabain solution and verapamil solution. The following results were obtained; 1. la a normal Tyrode solution, the fast compartment which is responsible for the fast decay of intracellular calcium within 3-5 seconds after the priming stimuli and the slow compartment, slowly decayed one after 5 seconds, could be identified. 2. Although the fast components showed no significant differences between those in a normal Tyrode solution and in a high calcium (4mM) solution, the slow components showed a rather increasing tendency during the normal initial decay period up to 20 seconds and later on a decreasing tendency. 3. In a ouabain, 2.4 -4.8×10^-7M, treated preparation the amplitude of contraction during the control period was increased up to 1.5 times compared with that in a normal Tyrode solution and the characteristics of calcium pools were qualitatively similar to those in high calcium solution. 4. In a verapamil, 1.1×10^-6M, containing solution the amplitude of control contraction were reduced to two thirds compared with that in normal Tyrode solution and the fast component were markedly influenced, reversed its slope to increase slowly up to 20 seconds and then decayed. 5. The characteristics of intracellular calcium pools la a preparation of verapamil and high calcium conditions at the same time showed rather similar patterns with those in verapamil alone treated preparation. The above results showed that the intracelluar calcium pools were composed of two components which were fast and slow decaying ones, and that ouabain and verapamil would alter the characteristics of the calcium pools to increase and decrease the intracellular calcium respectively.

강축양 심근에서 칼슘저장고에 관한 실험적 연구

조성일,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1981 中央醫大誌 Vol.6 No.2

1. The sequestration of activated intracellular Ca^++ ions in isolated Rabbit's cardiac papillary muscle cells, primed with square waves in normal Tyrode solution, histamine-Tyrode (3μM/L) and lanthanum-Tyrode (50μM/L), was studied by contractile responses to various test pulse interval. 2. In normal Tyrode, the disappearance of activated intracellular Ca^++ ions occurred in two pattern, i.e., the initial one was the fast component in which the contractility decreased rapidly within 5 sec. of test pulse, interval and the next, slow component in which the contractility decreased rather slowly following fast component. 3. In histamine-Tyrode, the contractility increased to 110.3±6.0% as compared with that in normal Tyrode. The fast component of Ca^++ ion disappearance was prolonged up to 10 sec. and a significant increase in contractile responses to test pulse manifested during this component. The slow component, however, was similar to that in normal Tyrode. 4. In lanthanum-Tyrode, the contractility decreased to 65.2±6.7% as compared with that in normal Tyrode. The fast component of Ca^++ ion disappearance was complete within 3 sec. of test pulse intervals and the slow component similar to that in normal Tyrode followed. 5. The data appear to indicate that the initial, rapid disappearance of activated Ca^++ ions, the fast component, was the result of sequestration of intracellular Ca^++ ions influxed across cell membrane from outside, and the next, slow component represented the sequestration of Ca^++ ions freed from intracellular storage site.

집토끼 동방결절부위별 자동능에 대한 CA^(2+)의 효과

방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1985 中央醫大誌 Vol.10 No.1

Effects of external Ca^2+ on the spontaneous firing rates of the isolated rabbit atria, the whole SA node, and the small strips of SA node at constant temperature were observed and analyzed by recording the transmembrane action potentials. The results were as follows: 1. It has been shown that a positive chronotropic effect in the isolated atrium and whole SA node has appeared at elevated Ca^2+ concentration. 2. On the contrary, negative chronotropic effect of Ca^2+ were observed in a small strip of SA node. 3. The each small strip of SA node could be divided into two kinds of cells, i.e., peripheral pacemaker cells and central pacemaker cells. In central pacemaker cells, Ca^2+ has shown positive chronotropy but opposite effect was observed in peripheral pacemaker cells. 4. The central pacemaker cells of the small strip of SA node could be divided into two groups with. configuration and parameters of action potentials. The two groups showed different degree of positive chronotropic effect respectively with elevated Ca^2+ concentration.

동방결절의 전기적특성에 미치는 Higenamine의 효과

이상돈,엄대용,조성일,방효원,윤병만 중앙대학교 의과대학 의과학연구소 1987 中央醫大誌 Vol.12 No.2

The rabbit sinoatrial node was cut into small pieces which wew 0.5×0.5㎜ in sizes, electrically insulated and could be partitioned into central and peripheral areas. Glass microelectrodes were impaled into both areas and transmenbrane potentials were recorded in order to observe the changes in effects of higenamine on the both areas by the addition of TEA, Cs^+ and Ba^2+ or pretreatment of propranolol. 1. Effects of higenamine were more prominent in high K^+ concentration than those in the low K^+ concentration. 2. TEA induced the decrease in the spontaneous firing rate and the prolongation in the action potential duration which could be reversed by higenamine. 3. Ther were prominent decrease of spontaneous firing rate and the prolongation in the action potential duration in peripheral area with the uncrease of Cs^+ concentration. Higenamine reversed the decrease of spontaneous firing rate in some degree. 4. There were significant decreases of spontaneous firing rate, amplitude of action potential and maximum diastolic potential by the Ba^2+ in peripheral area. Effects of Ba^2+ were reversed by higenamine in central area. 5. The effects of higenamine were completely blocked by the pre-treatment of propranolol. 6. There was no effect of higenamine of the Na-K pump activities. The above results could be interpreted as effects of higenamine were mediated by the chamge of calcium ion current rether than those of the potassium ion current in sinoatrial nodes.

나트륨 없는 용액이 세포내 �숨이온 활동도에 미치는 효과

조성일,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1982 中央醫大誌 Vol.7 No.4

The intracellular calcium ion activities were measured in the isolated papillary muscle empolying the microelectrode which was made selectively sensitive to Ca^++ by filling with ETH-1001, calcium selective neutral carrier. Changes of intracellular calcium ion activities in resting state superfused with normal Tyrode solution and during the development of centracture induced by superfusion with sodium-free Tyrode were investigated. REsults were summarized as follows; 1. Selectivity characteristics of Ca^++ selective electrodes to calcium were maintained for considerably longer period when 14wt.% PVC was added to ETH-1001 solution than ETH-1001 alone. 2. When calcium-selective electrode was inserted to miscle tissues at the resting period, mean value of intracellular calcium ion activity was pCa 7.1. This corresponds to 247 nM in terms of concentration,assuming the activity coefficient of intracellular calcium ion was same as that of extracellular Ca^++. 3. During superfusion with sodium-free Tyrode, the initial change of resting membrane potential was hyperpolarization which was returned to normal values before contracture was fully developed. In the initial periods, amplitides of twitch increased and the duration of action potertials was shortened. these changes are in agreement with those which are seen when the intracellular calcium selevated. 4. Contracture was induced by superfusing with, sodium-free Throde for 30∼60 min, and resting tension was restored to the control level, the muscle responded to stimulation. 5. The intracellular calcium ion activities were around pCa 4.7. in contractured state which corresponded to 104∼205% of control twitch tension. In terms of caclium ion activity, it was about 250 times greater than of resting state.

減少된 Na^+과 Cl^-濃度가 心房筋의 活動電壓과 收縮力에 미치는 影響

김만재,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1977 中央醫大誌 Vol.2 No.1

To investigate the effects of decreased extracellular Na and Ci ion concentration on atrial muscle of frog, changing patterns of single cell action potential by means of glass ultramicroelectrode and tension curves of isometric contraction in atrial muscle strips were recorded simultaneously. The results were as follows: 1. Decreased Na^+ and Cl^- concentration had little effects on resting transmembrane potential but amplitude of action potential and size of the overshoot were decreased along with the decrease of the concentration. The peak of the action potential had not reached "O" potential difference after 25 minutes bathing 1/2, 1/4 of the normal Na^+ and Cl^- concentration. 2. -dV/dt in plateau phase were tended to increase according to the decrease of Na^+ and Cl^- concentration and significantly increased in less than 1/4 of the normal concentration. -dV/dt in repolarization phase were scarcely affected to Na^+ & Cl^-. 3. Duration of action potential were significantly decreased in low concentration such as 1/2 of the normal Na^+ and Cl^- concentration. 4. Atrial muscle contractility were increased in decreased Na^+ & Cl^- concentration but the degree of increment were relatively decreased with time. 5. Frequency of the contraction were dominantly affected by decreased Na^+ & Cl^- than any other parameters and decreased. Above results were considered as that Na^+ played a important role in maintaining upstroke phase and slow inward current of plateau phase in atrial muscle action potential and Na^+ also had influence on the flux of Ca^++ across the membrane or the control of available intracellular Ca^++ concentration.

토끼 동방결절의 부위에 따른 전기생리학적 특성의 차이에 관한 연구

김덕호,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.2

By a 3M KCI glass microelectrode, transmembrane potentials were recorded in the compact and transitional areas bounded by superior, inferior vena cava and left, right, atria. The results were as followings: 1. In 35℃, normal Tyrode solution, the beating frequency, maximum diastolic potential (M.D.P.) and overshoot potential (O.P.) in the compact and transitional areas were 180±17/min. and 210±19/min., -76±3.7㎷ and -73±2.4㎷, 15±2.9㎷ and 19±2.8㎷ respectively which showed the transitional area was faster, and showed more positive M.D.P., more positive O.P. 2. Adrenaline made the transitional area more sensitively the frequency faster, more steeper the pacemaker potential, more positive the overshoot potential. 3. Tetrototoxin (TTX) has been found to be more sensitive on the transitional area to be less steeper the slope of pacemaker potential and the frequency slower. 4. Blocking the calcium current by 2mM Mn^2+ made the compact area, more sensitively and sometimes irreversible to reduce the beating frequency, overshoot potential and M.D.P.

한국산 뱀독이 개구리 심실근육세포의 수축력과 활동전압에 미치는 영향

한형일,방효원,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.3

In order to observe the effects of freeze-dried saliva of Agkistrodon caliginosus and Agkistrodon saxatilis, the Korean poisonous snakes, on the contractility and action potential of frog ventricular muscle cells, the isometric tension in a vertical chamber and the action potential in horizontal chamber were recorded and analyzed. The following results were obtained; 1. ED_50, to reduce the contractility was 4-8ug/ml in the case of A. saxatilis and 8-16ug/ml in the case of A. caliginosus which all were higher than that of A. brevicaudus and the inhibitory effect on the contractility was greater in the case of A. saxatilis than that of A. caliginosus. 2. In the case of A. saxatilis, APD_50(time to repolarize 50% of action potential amplitude) decreased from 820±80 ms to 710±60 ms, the overshoot and the V max(Maximum depolarization rate) decreased from 34±8 mV to 18±4 mV, from 98±8 V/s to 89±4 V/s respectively. 3. In the case of A. caliginosus, ADP_50 decreased from 880±70 ms to 720±40 ms, the overshoot and the V max decreased from 28±6 mV to 20±4 mV, from 89±8V/s to 77±12V/s, respectively. 4. Inhibition of contractility and overshoot potential were more prominent in A. saxatilis and APD_50 was more decreased in A. caliginosus. The above result showed that Korean snake venoms would decrease the ionic current underlying the rapid upstroke phase and slow inward currents by calcium ions simultaneously in a frog ventricular muscle cells.