[Effect of physiological stimuli on Oddi's sphincter motility].

The myoelectric activity of the sphincter of Oddi was studied both in the fasted and fed states and following administration of gastrointestinal hormones. Electromyographic recordings were obtained from 21 opossums in the fasted state and following administration of 20 Cal/kg of fat, protein, carbohydrate or isocaloric mixture of these three aliments. The proximal segment of the sphincter of Oddi generated spontaneous spike potentials that migrated to the distal segment of the sphincter. The frequency of spike potentials correlated with the migrating myoelectric complex in the duodenum. Following feeding, the migrating myoelectric complex was abolished and substituted by a fed pattern. The duration of the fed pattern and the frequency of spike potentials depended on the kind of aliment. Cholecystokinin and pentagastrin increased and glucagon and secretion decreased the frequency of spike potentials in the sphincter of Oddi. It is concluded from these studies that the sphincter of Oddi may play an important role in controlling the time and rate of biliary drainage into the duodenum.