AN ELECTROMYOGRAPHIC STUDY ON THE MECHANISM OF DELAYED GASTRIC EMPTYING AFTER VAGOTOMY IN THE DOG.

To clarify the mechanism of delayed gastric emptying after vagotomy, and the related problem whether the vagotomized stomach develops pylorospasm under any condition, the author studied the motor function of the canine stomach with the use of electromyography when warm water was instilled before and after vagotomy.Regardless of whether vagotomy had been performed or not, a marked excitation of the pyloric portion of the stomach occurred, resulting in a spasm-like abnormal excitation and anti-peristalsis as the intra-gastric pressure was risen by instillation of water. However, the vagotomized stomach required much more water than the non -vagotomized stomach to develop the same degree of excitation of the pyloric portion, and this difference was probably due to hypomotility or hypotonicity of the vagotomized stomach. On the other hand, vagotomy did not cause pylorospasm or abnormal excitation of the pyloric portion, although hypomotility of the stomach was present.The above results suggested that the vagotomized stomach developed hypomotility or hypotonicity first, resulting in stasis and retention of the gastric content. And, the higher intra-gastric pressure due to this stasis and retention was followed by the occurrence of spasm-like abnormal excitation of the pyloric portion and anti -peristalsis. Therefore, “pylorospasm” was considered to occur secondarily as a result of gastric stasis and retention, but not primarily because of vagotomy.