超微小電極法による生体内平滑筋細胞内電位の研究

抄録

1. With applying flexiblly mounted urtramicroelectrodes, the intracellular electric potentials in ginea-pig's tenia coli and haustra coli in situ were successfully recorded and the following results were obtained.
2. The resting potentials of the tenia coli are ranging in 30 mV to 60 mV and the action potentials are recorded up to 30 mV without overshoot usually 4 mV to 10 mV (average 7.9±0.7 mV). The spike duration is 241±29 msec. repeating 0.5-2.5 sec in periods. Haustra coli presents a grouping of the spikes 1-8 pieces with 2 to 30 sec. intervals.
3. Two kinds of slow potentials are observed. The formar type of them is local potentials which are resulted from spontaneous excitation of its cell or of the adjacent cells, then behave as generator prior to the spike activity. The second type of the slow potentials is consisted with slow movoments of the resting level appearing in about 5 seconds periods, which are corresponding to fluctuation on the electromechanogram. Usually the spike potentials are appeared in equal intervals on the slow potentials II, and are predominant on their rising phase and are disminished on the declining phase as if having a closed relation between the spike potentiall and the slow potentials II.
4. There are some distinguishable differences of the results obtaining in situ from those in isolated tenia coli as follow;
1) In situ the periods of the spike potentials are distributed in 0.5 sec. up to 2.5 sec. with variable.
2) Spontaneous alteration of the spike configulation and arresting of the spike activity are observed not infrequently.
3) The slow potentials II is prominent.
5. With administration af Acetylcholine or Neostigmine i. m. or i. v., it appeares a decreasing of the resting potentials and a prolongation of the repolarizing phase. These facts seem to due to accentuation of nonspecific ion permiability of the protoplasmic membrane.
6. With Adrenaline i. m. a rising resting potentials decreasing of the spike frequency, a steeping of the spike configuration, and isolation of the prepotentials are observed. These phenomena seem to be caused by a rising threshold of the spike depolarization and due to vascular effects as well as to neurogenic effects directly by Adrenaline in some extends.
7. Atropine, Chloropromazine and Buscopan make the resting potential increased, also result in sharp gradient in the spike configuration, distinuished multiple spikes, grouping of the spikes. So that these drugs seem to be responsible to lowering of the electric activity of the cells and disjunction of the cells.
8. In experimental ileus, the spike discharge is observed in group corresponding to the phasic contraction. The both depolarizing and repolarizing phase are prolomged and are associated by various spike configuration, also the arresting intervals are prominent. The above facts are resulted from direct effects of an obstructive toxin as well as edema and circulatory disturbance of the local area.
9. Experimentally interrupted blood circulation result in both depolarizing and repolarizing phases prolonged marKedly as time is passed on. These phenomena are recovered with recirculation of the blood, local response to A. T. P., or rising local temperature in some extends. In these facts, temporal anoxia cause a disturbance of ionic pump mechanism accompanied by an impairment of intracellular oxygeration and ATP mechanism. It is very interested in clinical aspects.
10. The above esperimental evidences are concluded as the action potentials are myogenic and each cells have a syncytial continuity in their function.