The concentration-effect curves were established for the action of isoproterenol on the tracheal muscle of guinea pigs pretreated with such beta-adrenergic blocking agents as H 56/28 (1-(ο-allylphenoxy)-3-iso-propylamino-2-propanol), propranolol, pronethalol, and methoxamine. Then analysis was made of the antagonistic effect of beta-adrenergic blocking agents against isoproterenol and of the mode of action of isoproterenol and beta-adrenergic blocking agents at the adrenergic receptor.
1) The ratio of the intensity of the antagonistic effect of propranolol, H 56/28, pronethalol, and methoxamine was found to be 1: 1.5: 1/18: 1/1000; H 56/28 exerted the most intense antagonistic action.
2) When analysis was made of the concentration-effect curves established for the antagonistic action of beta-adrenergic blocking agents against isoproterenol in two different way of plotting, it could be said that the agonist competes with the antagonist for the receptor of the tracheal muscle.
3) Isoptoterenol showed a strong beta-adrenergic receptor activity on the trachea of guinea pigs. And yet it can not be said that the drug has no alpha-adrenergic receptor activity.

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The responses of the chicken gizzard to stimulation of the vagus, splanch-nic nerves and medulla oblongata were examined.
1. Both excitatory and inhibitory responses of gizzard were obtained to stimulation of the vagus and splanchnic nerves in each. The excitatory response was abolished after the application of atropine, and the inhibitory response was abolished after the application of propranolol and C₆.
2. The stimulation of medulla oblongata caused both excitatory and inhibitory effects to the stomach movements. The stimulated areas were examined histologically. The excitatory areas (vagal & splanchnic) were found in the dorsal nucleus of vagus and dorsal region of reticular formation. The inhibitory areas (vagal & splanchnic) were also found in the dorsal nucleus of vagus, reticular formation and solitary tracts.

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The responses of movements of the distal colon to stimulating dog's medulla oblongata were examined.
1. The excitatory response of movements of the distal colon was demonstrated to stimulating medulla oblongata. The excitatory pathways to the colon from the spinal cord were not only the pelvic nerves, but also the sympathetic nerves such as the hypogastric and lumbar colonic nerves.
2. The inhibitory response of movements of the distal colon was also demonstrated to stimulating medulla oblongata through the hypogastric and lumbar colonic nerves. The inhibitory response through the pelvic nerves was not observed.
3. The excitatory and inhibitory areas in the medulla oblongata were examined histologically (see Fig. 4). The excitatory areas were found in the dorsal and medial region of reticular formation, solitary tract and its nucleus and dorsal nucleus of vagus. These regions also responsible for the inhibitory areas.

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The responses of the movements of distal colon to stimulating dog's lumbar cord were examined. The stimulated areas in the lumbar cord which were responsible for the changes of colon motility were investigated histologically.
1. The inhibitory and excitatory responses of movements of the distal colon were observed by the stimulation of lumbar cord. The inhibitory response was obtained through the ventral roots of the hypogastric and lumbar colonic nerves. The excitatory response was obtained through the dorsal roots of the hypogastric and lumbar colonic nerves. The excitatory response was abolished after application of atropine.
2. The inhibitory areas were almost located in the ventral column, i.e. Cellulae mediales ventrales, Cellulae latero-ventrales, Cellulae latero-dorsales externae. The inhibitory areas were also found in the lateral and median regions of intermediate substance.
The excitatory areas were located in the intermediate substance and dorsal column, i.e. Cellulae cornu-commissurales posteriores, Cellulae dorsomedialis, Cervix cornu dorsalis spinalis, and Cellulae intercornuales laterales.

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Peristaltic movements of dog intestine (Thiry-Vella loop), and rabbit stomach and duodenum were inhibited by the intravenous administration with higher dosage (5-25 mg/kg) of thiamine (B₁-HCl) or 0, 5-dicarbethoxythiamine (DCET), a derivative of S-Alkoxycarbonylthiamine (S-CAT). Inhibitory effects of B₁-HCI on the peristaltic movements were superior to those of POET, while propulsion of charcoal meal both in the small intestine and large intestine of mice was not affected by B₁-HCI or POET.
In the isolated intestine of rabbits, its pendular movements were inhibited by thiamine derivatives with the following order of potency; DCET≥ Scarbobutoxythiamine (CBT) > S-carbethoxythiamine (CET) =B₁-HCI. Inhibitory effect of B₁-HCl on the peristaltic reflex in the guinea-pig isolated intestine was similar to that of hexamethonium, while that of POET was atropine-like. In the guinea-pig isolated intestine, B₁-HCl specifically antagnized to the nicotine contracture but S-CAT did to not only nicotine but also other spasmogens such as acetylcholine, histamine, barium. Anti-barium effects of thiole derivatives (CET, POET) were also observed in the isolated circular muscle strips of dog intestine, but no effects were observed by the administration of thiazole derivatives (B₁-HCl, O-carbethoxythiamine).
These findings suggest that inhibitory effects of B₁-HCI on the gastrointestinal motility were due to the depression of parasympathetic ganglion in the Auerbach's nerve plexus, but those of S-CAT were not so specific as B₁-HCl.

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A “work hypertrophy” due to spasm of the pyloric portion is widely accepted as basic cause of infantile hypertrophic pyloric stenosis. From the view of above hypothesis, electromyographical investigation has been performed on the pylorus of 12 ill infants and 5 control patients. Prior to Ramstedt's operation, electrical activities were recorded for the purpose of detecting changes between the tumor and the unhypertrophied antrum.
Results are as follows:
1) Electrical activities were classified to two different types, regular and irregular discharge patterns. However, there existed any pecuriarity of pattern in neither tumor nor unhypertrophied antrum.
2) Synchronization of the regular patterns of the two sites was demonstrated in half of the infants, and suggests propagation of excitation from one to another site. On the other hand, desynchronization of the patterns of the two sites occured in the residual infants. This latter phenomenon is possibly ascribed to abnormal excitation of the gastric wall muscle or disturbance of propagation in the pyloric portion.
3) Mean values of the discharge intervals of the regular patterns at the tumor were calculated in 9 infants and ranged from 22.6 sec. to 29.7 sec. with an average of 25.4 sec. It is apparent that the discharge intervals were markedly prolonged in comparison with an average of 18.1 sec. of the control patients. The prolongation of the discharge intervals was also revealed in the unhypertrophied antrum. The prolonged discharge intervals are probably referred to excited state of the pyloric portion.
4) From the unusual electrical activities mentioned above, the dysfunction of the whole pylorus is considered to be present, indicating that the stomach of these infants tends to lose the ability to propel its contents into the distal region.

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