[The relationship in the diurnal rhythm of electrical and mechanical activity between the stomach and the duodenum in dogs].

Simultaneous 24 hrs' polygraphic recording of the electrical potentials and the contractions of the stomach and duodenum was done in the unanesthetized state of mongrel dogs with chronically implanted electrodes and their interrelationship between these two organs was studied. The results obtained were as follows: In contrast to the diurnal rhythm of gastric activity after feeding, the frequency of the duodenal basic electric rhythm (BER) once increased immediately after feeding and thereafter gradually decreased during the fed state. A negative correlation was found with statistical significance between the frequencies of the gastric and duodenal BERs during the fed state. Tachygastria exhibiting the high frequency BER appeared in the antrum at the silent period of the fasting state, while any similar phenomena were not observed in the duodenum. In the fasting state, the interdigestive migrating contraction (IMC) occurred periodically and synchronously with each other of the two organs. Regarding each contraction, the duodenal contraction was inhibited at a strong contraction of the stomach. These results suggest that the BERs of the stomach and duodenum are not directly propagated to each other and that some reciprocal interaction between the two organs may come out in the fed state probably by reflexes via intramural nerve plexuses.