A model for simultaneous study of pressure and electric events in the rabbit sphincter of Oddi and duodenum

An animal experimental model featuring simultaneous recordings of electromyography and pressure from the sphincter of Oddi (SO) and duodenum is demonstrated. On the basis of data from 10 rabbits, pressure recordings from the SO were shown to have phasic activity with an average basic pressure peak interval of 2.6 to 3.5 sec. Histographic analysis of SO pressure recordings showed a multimodal appearance, suggesting that the activity is paced. A substantial amount of overlap between SO and duodenal contractions was observed. As many as 30% of the pressure peaks recorded from the SO could not be assigned to a spike complex in the corresponding EMG tracings. It is suggested that combined recordings of EMG and pressure activity are needed to characterize fully the motility of the SO and duodenum.