Ethanol이 고양이 회장 종주근의 수축에 미치는 영향을 관찰한 결과 정상 Tyrode용액에서는 0.5±4% 범위내에서 자발적 수축 및 기초장력을 억제하였으나 Na+이 surcose로 대치된 용액에서는 수축을 유발시켰다. 이러한 수축은 ethanol의 농도에 비례하여 증가하였으며 용액내의 Na-free 용액으로 처리한 기간이 길수록 증가하였다. 용액내 Ca2+이 없는 경우에도 ethanol에 의한 수축은 La3+에 의해 억제되었으나 verapamil을 전처치한 후 Na-free액을 처리했을 때는 수축이 나타나지를 않았다. Ethanol은 45Ca의 유출에는 어떤 영향을 나타내지는 못하였다. 이상의 결과로 보아 Na-free용액에서 ethanol은 세포막에 결합하고 있는 Ca2+이나 세포내부에 결합하고 있는 Ca2+의 세포내로 유리를 증가시켜 수축을 유발시키는 것으로 사료된다.
The effect of ethanol on the contraction of intestinal smooth muscle in Na-free solution was studied using cat ileal longitudinal muscle strips. Ethanol (0.5±4%) inhibited both the spontaneous mechanical activity and base-line tension in normal physiological salt solution. However, in Na-free solution it induced a reversible contraction. The excitatory effect by ethanol in Na-free solution was increased with increasing the concentrations of ethanol and the time incubated in Na-free solution. The excitatory response by ethanol was reduced by increasing the concentrations of Na in incubated medium . Ethanol-induced contractile response was not affected by Ca2+ removal in bathing medium. In Na-free solution, the contraction by ethanol was inhibited by La3+ but was not affected by verapamil. The contraction induced by Na removal in solution was inhibited by the pretreatment of ethanol. These results suggest that ethanol may induce the contraction by increasing the release of superficially membrane-bound Ca2+ and/or intracellular Ca2+ in Na-free physiological salt solution.
