산·염기 변화가 개구리 심방근 활동전압에 미치는 효과 = Effects of Acid-Base on Action Potential of Frog Atrial Muscle

다국어 초록 (Multilingual Abstract)

Frog atrial muscle preparations were used to investigate effects of acid-base disturbances on the resting membrane potential and action potential on a cellular basis.
To record the action potential of atrial muscle cells, 3M KCL-filled glass microelectrodes were directly introduced into the muscle cells in acidic(pH 6.0) and alkali(pH 8.0) conditions which were induced by addition of HCl and NaOH respectively into media.
The following results were obtained :
1. In acidic condition, the resting membrane potential hyperpolarized from -(80±4.1)mV(P<0.05) and the overshoot potential was decreased significantly from 26±2.4mV of the control to 18±1.7mV(p<0.001). The time needed to repolarize 90% of the action potential duration, (repol 90%) shortened from 460~560 msec of the control to 400~520 msec in acidic intervention.
2. Little effect on resting membrane potential and action potential amplitude was observed in the alkali condition but Repol 90% shortened from 420~520 msec of the control 380~460 msec. (p<0.001) above results may be interpreted as that hydrogen ion affects the surface charge density at atrial muscle cells in such a way to inhibit ionic currents, especially slow inward and delayed outward currents.