Retrograde electrical pacing and its influence on the migrating motor complex of the canine jejunum

A STUDY was undertaken to evaluate the effect of retrograde electrical pacing on the mechanical component of the migrating myoelectrical complex. Jejunal transections and reanastomoses were performed on five dogs at 20 cms and 60 cms from the Ligament of Treitz. Electrical and motor activity were recorded using stainless steel electrodes and serosal strain gauges placed within the segment. Retrograde electrical pacing was achieved by electrical stimuli using electrodes just proximal to the distal transection. Each fasting dog was studied on four occasions with and without retrograde electrical pacing for two hours following the appearance of a migrating motor complex. In a separate study of fed dogs the times of reappearance of migrating motor complexes with or without pacing were compared. Results showed that retrograde pacing does not alter the migrating motor complex except in its frequency of contractions which were significantly increased (13.6 ± 0.3 versus 17.8 ± 0.4 per min, p<0.01 ). Retrograde electrical pacing did not significantly delay the reappearance of migrating motor complexes after feeding. These findings are consistent with the hypothesis that migrating motor complex propagation is controlled by extrinsic nerves and suggests that retrograde pacing will have little effect on transit during fasting.