Differential response to various stimulants in the body and antrum of the canine stomach

Abstract

This study was initiated to evaluate gastric motility with the use of extraluminal force transducers in unanesthetized dogs. The contractile activity of the circular and longitudinal muscle in both antrum and body of the canine stomach was monitored in the interdigestive state and under the influence of food, acetylcholine, and 5-hydroxytryptophane. The latter two chemicals were infused for a 30-min. period. Each of the two muscle layers in antrum and body had a maximum frequency of 5 contractions per minute. This activity was continuous during 30 min. only under the influence of food and 5-hydroxytryptophane. Acetylcholine stimulant effects did not persist beyond the initial 10 min. of infusion. Amplitude of contractions under spontaneous or induced activity varied. The height of these contractions were circular antrum > longitudinal antrum > circular body > longitudinal body. This method of recording muscle contractility is believed to be useful for quantitatively assaying gastric activity without compromise of physiologic environment.