The role of the cholinergic nervous system in the gastrointestinal response to motilin in vivo

Abstract

The controls over the pattern of motor activity in the interdigestive state of dog and man have not been fully elucidated. Carlson and co-workers¹ postulated that extrinsic nerves were responsible for the initiation and the propagation of the interdigestive migrating myoelectric complex. Their experiments in dogs with Thiry-Vella loops demonstrated that continuity of the jejunal bowel wall was not an important factor in the control of the migrating complex. Carlson’s hypothesis received support from the work of Weisbrodt et al.², which showed that the myoelectric complex did not occur on a denervated Thiry-Vella loop. However, Marik and Code³ and Weisbrodt et al.⁴ demonstrated the presence of interdigestive migrating complexes following truncal vagotomy. Therefore, the vagus nerve may not have a primary role in initiating and maintaining these complexes although it may be involved in the timing of each complex. Other factors, such as circulating levels of gastrin³, also appear to be instrumental in the control of interdigestive motor activity.