Differences in peristalsis and its conduction accordance with various portions of the stomach and duodenum

Abstract

One hundred and thirteen dogs were examined their motilities of the stomachs and dudodenums by means of the electromyograph and mechanical tracing with strain meter additional use of electric stimulation with audio frequency square wave. The results were follows:1) The origin of the action potentials of stomach was situated at the border line between oblique muscle area and fundic muscle area. The peristalsis occured almost the same line.2) After transection or Devine's operation or temporary circular block using clamps, the differences in frequencies of action potentials between body and antrum were recognized. It seems the frequency from the body dominated on the peristalsis in normal condition.3) By longitudinal section and block on lesser or greater curvature, the predominance of greater curvature was evidenced.4) The amplitude of peristalsis stimulated by neostigmin or square wave were higher in the lower portions of stomach or greater curvature side than upper portions or lesser curvature side.5) The thresholds for circular contraction by the electric stimulation were lower in lower portions and greater curvature side of body. But on the antrum, there was no difference between these portions.6) After the electric stimulation artificial action potentials occured and propagated downwards. Only in the antrum the anti-peristaltic potentials were odserveb.7) On the simultaneous recording of electromyography and mechanical tracing, the propagation of action potential and the peristalsis were observed together. The distance of propagation of peristalsis was shorter than that of action potential.8) After the contraction of pylorus by the electric stimulation, the spike bursts of the duodenum occured and the duodenal peristalsis followed them. The mechanism of conduction is still remained unexplained, but the excitation of duodenum synchroniz-ing with gastric excitation are evidently observed.9) On the duodenum, normo-peristalsis was absolutely predominant. And the distances of conduction were 5-10 cms.