Background: The aim was to determine the effect of proximal gastric vagotomy on proximal gastric tone, distal gastric motility, and gastric emptying in seven conscious dogs.
Methods and results: Before vagotomy, insulin (1 unit/kg intravenously) caused a prompt decrease in proximal gastric tone measured with a barostat and a marked increase in distal gastric motility measured with a perfused, pressure-sensitive catheter, both of which were maximal at 30 minutes. Proximal gastric tone then returned to the control level during the ensuing 30 minutes, whereas the increase in distal gastric motility continued. Gastric emptying of an inert marker, polyethylene glycol, was unchanged by insulin. After vagotomy, insulin again caused a prompt decrease in proximal gastric tone, an increase in distal gastric motility, and no change in gastric emptying of marker, but the decrease in proximal gastric tone now persisted for the entire hour after administration of insulin.
Conclusions: Relaxation of the proximal stomach is mediated by pathways not solely dependent on the proximal gastric vagal nerves, but the ability to regain proximal gastric tone is impaired by proximal vagotomy. In contrast, vagal drive to distal gastric motility and gastric antral emptying are preserved after proximal gastric vagotomy.