The effects of subtotal-gastrectomy (gastrectomy) on the spontaneous motility and caerulein-induced relaxation of the sphincter of Oddi (SO) were investigated in the dog. The spontaneous motility and the response to caerulein ofthe SO were recorded using perfusion method.
The basal perfusion pressure (5.1±0.5 cmH₂O) and the frequency of phasic contractions (6.1±0.5 cycles/min, c/min) of the SO increased to 8.2±0.6 cmH₂0 (p<0.05) and 9.3±0.4c/min (p<0.05) after gastrectomy, respectively. They were observed one month after operation (7.8±0.5 cmH₂O and 9.1±0.9 c/min, p<0.05), but did not change by vagotomy with sympathectomy (vagosympathectomy).
In the spontaneous motility of the SO, the motility index increased to 143.7±18.7% (p<0.05) at 4 hrs and 135.0±9.1% (p<0.05) at one month after gastrectomy, but did not increase after vagosympathectomy.
Caerulein had an inhibitory effect on the SO motility in the normal animal (48.0±4.2%). Gastrectomy reversed to the excitatory effect from theinhibitory effect to caerulein at 4 hrs (127.6±5.3%, p<0.05) and at one month (126.6±5.3%, p<0.05) after operation, but not reversed by vagosympathectomy and sham gastrectomy. The excitatory response to caerulein after gastrectomy was not effected by vagosympathectomy. It is concluded that gastrectomy induced the SO dysfunction, an increase of the perfusion pressure and the frequency of phasic contractions of the SO, and a change of the response to caerulein of the SO. Thesealterations suggests that one of the mechanisms of the regulation of the SO motility exist as the reflex from the stomach and/or uppermost duodenum through intrinsic nervous pathways.

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Dysmotility of lower esophageal sphincter (LES) is common follwing gastric surgery. This may result in gastroesophageal reflux which freqently seen following gastric surgery. The aim of this study was to determine the effect of various surgical procedures on esophagogastric motility in dog and human. Esophago-gastric motillity was investigated by strain gauge transducers during fasted and fed state in conscious dogs. Motility recordings were performed in three groups of dogs, 1) control dogs, 2) with truncal vagotomized dogs (TV), 3) with selective proximal vagotomized dogs (SPV). In human, manometric recordings were performed before and after gastric surgery (SPV or distal partial gastrectomy). In control animals, lower esophagus and LES contracted simultaneously with each contractions of the stomach during interdigesive moter contractions in fasted state. In fed state, LES showed tonic contractions, while gastric body showed receptive relaxation. These motility pattern of LES was considerd to prevent gastroesophageal reflux in both fasted and fed states. These coordinated LES contractions disappeared following SPV or TV. In human, the amplitude and velocity of esophageal propagating contractions deceased after SPV or distal partial gastrectomy. In conclusion, gastric surgeries such as SPV, TV and/or distal partial gastrectomy caused LES dysmotility. These phenomena explain frequent gastroesophageal reflux following gastric surgery. Suplementation of anti-reflux procedure for gastric surgery should be required in the prevention of gastroeso-phageal reflux following gastric surgery.

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Our objective was to study the mechanism of action of gastrin and histamin H2 receptor antagonist on the motility of the gastrointestinal area.
In each of 12 mongrel dogs, eight bipolar electromyograms were obtained from the antrum of the stomach to the ileum on serosal surface, and in nine dogs undergoing that the small intestine was transected 20 cm from the ligament of Treitz.
The effects of tetragastrin (1.0-10.0μg·kg^-1·h^-1) were studied against the presence of atropine, cimetidine and d-chlorpheniramine maleate.
The frequency of electrical control activity (ECA) along the canine small intestine, and changes in ECAs frequency were studied normal and following upper small intestinal transection. In intact, the frequency of ECAs gradient decreased aborally in a stepwise fashion in normal intestine. Although the gradient was markedly reduced or even abolished distal to the level of transection, an intrinsic ECAs frequency gradient was demonstrated, it remained at a low level indefinitely. The normal ECA pattern and its alterations following transection were significantly influenced by tetragastrin.
The act of tetragastrin in a dose of 1.0 to 5.0μg·kg^-1·h^-1 had not statistically effect on ECAs frequency and its dysrhythmias, and it did cause a small increase in the frequency of ECA at the antrum, whereas, with the highest dose (10.0μg·kg^-1·h^-1) of used, the increase of mean frequency of ECA in the distal portion to the line of transection, in particular, was significantly greater compared to the change in the proximal portion.
It was only cimetidine (8.0 mg·kg^-1) that antagonized this action of tetragastin (10.0μg·kg^-1·h^-1). Histamine H2 receptors are suspected of being associated with the action the gastrin has of enhancing ECAs frequency.
The results of this study indicate that histamine H2 receptors regularize gastrointestinal ECAs frequency.

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In order to study the physiological changes in the intestinal movement after total gastrectomy with jejunal interposition, electromyography was taken from different sites of small intestine of the dogs with and without gastrectomy.
Both 6 and 12 months after surgery, the frequency of the basic electric rhythm (BER) of interposed jejunum was lower and that of distal jejunum was much lower than that of duodenum. Most of the interdigestive migrating electric complexes (IMEC) was originated in the oral side of the interposed jejunum; the rate of occurence increased after the operation further and reached to 91.5% one year after the operation. Most of the dogs showed the propagation pattern from interposed jejunumto duodenum and to distal jejunum; this tendency increased afer the operation and 80.8% of the dogs showed this pattern one year after the operation.
Thus, the IMEC, conducted usual intestinal order disappeared after the operation and those originated from oral to anal side, regardless of their original order. These results suggest that the order of the propagation of IMEC were determined bythe order of the portion of intestine after operation and the parietal continuity, rather than extrinsic nerves, is involved in the propagation. It is also suggested that the propagation of IMEC is not always correlated with the gradient in the difference of the BER between the replaced jejunum and duodenum.

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