RISS 검색 - 국내학술지논문 상세보기

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다국어 초록 (Multilingual Abstract)

In order to investigate the effects of magnesium ion on intracellular potaential of cardiac muscle, a guinea-pig papillary muscle preparation was excised out to a in vitro contraction chamber and the isometric contraction of the preparation was recorded in normal Tyrode's solution by a control stimuli(0.5Hz) and then intracellualr potenital was depolarized by potassimu 19mM/L Tyrode's solution,
After partially depolarization to-55-60mV with potassium ion, magnesium ion were applied from normal(1mM/L) to 16 mM/L.
The following results were obtained;
1. In normal Tyrode's solution, addition of magnessium ion had no significant effect on the action potential paramenters except upstroke veolcities and contractility.
2. In potassium 19mM/L Tyrode's solution, upstroke velocities and duration of action potential of papillary muscle were changed by addition of magnesium ion. And upstroke velocities separated with an initial first peak that manifect as a sharp and blunt second peak.
3. By increase of concentration of magnesium, first peak of upstroke velocities increased but second peak decreased.
4. With 14mM/L magnesium ion in partially depolarized preparation, second peak was disappeared by change of calcium ion concentration from normal(2mM/L) to 0.4mM/L.
5. According to change of concentration of calcium ion from 0.4mM/L to 2mM/L by 0.4mM/L step, first peak of upstroke velocities changed 14.3+1.8V/Sec (mean±1.9V/Sec, 19.5±l.5V/Sec, 22.0±1.3V/Sec, 24.4±1.5V/Sec, and second peak changed 0V/Sec, 1.3±0.1V/Sec, 2.5±0.1V/Sec, 3.4±0.1V/Sec, and 4.2±0.1V/Sec.
6. With treatment of TTX(tetrodotxin: 0.1mg/L), first peak changed with concentration of calcium ion, but upstroke velocities were declined to values of 5.7±2.0V/Sec., 9.7±2.0V/Sec, 10.8±1.2V/Sec, 13.6±1.8V/Sec., and 16.7±2.0V/Sec. But second peak had no significant change.
Above result suggest that magnesium ion induced first peak was affected by sodium ion in partially depolarized cardiac muscle.