Abstract
1) The effects of N-(diethylaminoethyl)-2-methoxy-4-amino-5-chlorobenzamide dihydrochloride (metoclopramide) upon the motility of the colon of dogs as well as of rats were studied.
2) When 5 mg/kg of metoclopramide was intravenously administered, there was usually produced an excitatory effect upon the motility of the innervated as well as denervated colon of dogs. The sensitivity of the colon to the drug was increased by severing the extra-colonic nerves, i.e., vagus, pelvic, splanchnic, lumbar sympathetic, hypogastric and colonic nerves.
3) In the concentration ranging from 10-6 to 5×10-5g/ml the drug produced a remarkable augmentation of the motility of the rat colon, in vitro, and the effect remained unchanged after administration of tetrodotoxin, the drug which is regarded as an agent that paralyzes the intramural nervous elements.
4) From the results described in 2) and 3) it may be concluded that metoclopramide exerts the excitatory action upon the colonic muscle.
