S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 21 No.4 (1980)
에타놀이 심근 수축성에 미치는 영향 : Effects of ethanol on the contractility and action potential in isolated rabbit papillary muscles
Cited 0 time in Web of Science Cited 0 time in Scopus
- Issue Date
- 서울대학교 의과대학
- Seoul J Med, Vol.21 No.4, pp. 359-364
- The effects of ethanol on the myocardial contractile
force and action potential were studied in isolated
rabbit papillary muscles. All experiments were performed in HCO-a-buffered Tyrode solution which
was aerated with 3% CO,-97% 0, and kept pH
7.35 at 35°C. Action potentials were measured by
conventional microelectrode technique. Glass microelectrodes
were filled with 3M KCI and had a resistance
of 20~30 megohms.
Ethanol depressed the contractility of the rabbit
papillary muscle at concentrations between 1 and
20gm/1 dose-dependently; Ethanol reduced peak developed
tension by 5% at a concentration of Igm/l,
15~0 at 2gm/I, 30% at 4gm/I, 50% at 6gm/I, and
80% at 12gm/I, respectively. There was no effect on
resting tension. A similar degree of depression was
observed in the maximum rate of tension development
CdP/dt). The effects were reversible in all cases.
Shortening of the action potential duration, especially
50% repolarization time, with the reduction
in contractility. was the most characteristic change
in the electrical properties. The amplitude and duration
of action potential were decreased in a dosedependent
manner by ethanol. The resting membrane
potential, however, was unaffected by ethanol. The
action potential duration in the muscle hypopolarized
by 18mM K-Tyrode was also shortened, but its
height remained almost unchanged.
The results of this experiment suggest that the
depression of the contractility by ethanol can be
attributed to the shortening of action potential duration,
especially to inhibition of Ca·current.
- Files in This Item:
Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.