On the Effects of Several Drugs upon the Action Currents of the Small Intestine

Abstract

Berkson7) and others observed that when nicotine was applied, the intestinal activity became vigorous, but its action currents disappeared. In my experiments the disappearance of action currents could not be recognized, but the electrical records showed the changes with very small waves a few minutes after the application. And they described that when epinephrine was used the activity of intestine stopped at once, but the electrical wave was hardly influenced. In my experiments it was in-fluenced clearly in both cases of an intact intestine and excised one. They stated moreover that the effects obtained with atropine were similar to those by adrenaline reported above. In my case this fact was observed in an intact intestine, but when the excised one was used, the electrical records showed the peculiar wave, which was described above already. Further, it has been recognized that when the intestinal movements are more vigorous by the effects of some drugs e.g. pilocarpine, vagostigmin, acetylcholine or histamine, the electrical wave becomes greater in its period and amplitude and when the movements are inhibitted, it becomes smaller. It was true in case of adrenaline, as was mentioned above. Namely in my experiments it has been shown that two responses, which are potential changes and mechanical ones, react with some drugs differently, and at the physiological conditions or by means of some drugs the period and the amplitude of the electrical curve change generally in parallel with the variation of the intestinal activity. However, the degree of variations which two responses demonstrate differs from each other. So there is probably included in the electrical curve an important factor which may be distinguished from the action currents made by musclar activity. Accordingly it will be assumed that the intestinal action currents contain two elements; that is, the action currents which have their origin in the intrinsic nervous system or in the chemical changes in the muscle, and which are made by the intestinal activity.