Abstract
1. The effects of morphine upon the motility of the aganglionic, denervated and normal THIRY-je j unal loops of unanesthetized dogs were studied.
a) The intravenous administration of the amount of morphine ranging from 0.001 to 1.2mg/kg always produced an abrupt rise of tone accompanied with the decrease in superimposed rhythmic contractions in their amplitude. The tone was then gradually decreased accompanied with the increase in rhythmic contractions in their amplitude.At this stage the undulation of both tone and rhythmic contractions almost entirely disappeared.
b) It may be concluded that morphine acts as an excitant to the intestinal muscle itself, since the drug can raise the motility of the aganglionic loop.
2. Morphine could raise the intestinal motility which was previously depressed by atropine as well as by hexarnethonium.
3. The intravenous administration of morphine produced a transitory retardation followed by acceleration in the flow of fluid through the intestinal segment.
