Effects of Dopaminergic Blocking Agents on Distal Colon Motility

Abstract
Four different dopaminergic blocking agents modified the motility of the distal colon: haloperidol, sulpiride, pimozide and thioridazine. Haloperidol and sulpiride induced different and frequently antagonistic responses but the effects induced by these drugs changed depending on the preexisting pattern of motility. Intestinal tone and sigmoidal or rectal phasic activity predominance are the main factors that influence responses. Biperiden, a centrally acting anticholinergic drug, and dihydroergotamine, an antinoradrenergic drug, annulled the rebound of motility induced by sulpiride in high intestinal-tone and low intestinal-tone subjects, respectively. Apparently the dopaminergic system is important in the distal colon motility in humans.