THE RELATION OF THE ACTION POTENTIALS TO MECHANICAL ACTIVITY IN INTESTINAL MUSCLE

Abstract

In agreement with previous results on other visceral muscles, differential potentials from the small intestine show R and T waves. The monophasic potentials derived from these potentials have a long plateau like that of cardiac muscle, but spikes are usually superimposed on it. Each potential is followed by a contraction but there is no close relation between the height of contraction and the magnitude of the slow phase of the potential. However, with increasing strength of contraction, the size and number of the spikes increases. Adrenaline stops electric activity only in unphysiologic concris. although mechanical activity is almost completely abolished by small amts. of the drug. In the guinea pig, the potentials consist only of brief spikes.