1) Pyrodifenium bromide, 3μg-5 mg/kg, inhibited the motilities of both the stomach and small intestine of dogs, and the drug, when administered in an amount 3 mg/kg, abolished the excitatory effect of vagal stimulation upon the intestinal motility.
The drug, in the concentration of 10-9-5×10-5 g/ml, depressed the motility of the isolated small intestine of rabbits, guinea pigs and rats, and it in the concentration of 5×10-5 g/ml prevented 10-8-10-5 g/ml of acetylholince from acting excitatorily upon the intestinal motility, while it had no influence upon the inhibitory effect produced by applying 10-7 g/ml of adrenaline or by the stimulation of the mesenteric nerves.
2) After administering the drug, 5-10mg/kg intravenously, the inhibitory effect of the preganglionic splanchnic stimulation was reduced or completely abolished, while its postganglionic stimulation produced the inhibitory effect similar to that observed before administration of the drug.
3) It may, firstly, be concluded that the drug in small to moderate doses prevents acetylcholine released from the intramural nervous elements to act upon the intestinal motility, while the drug has no influence upon the inhibitory effect of the sympathetic nerve and, secondly, that the drug, when given in a large dose, can block the synaptic transmission at the autonomic ganglia.
