Effects of cholecystokinin on the motility of the distal duodenum and the proximal jujunum in man.

Electrical spike potentials and intraluminal pressure variations were recorded in the distal part of the duodenum and proximal part of the jejunum in 5 normal human subjects before and after a bolus injection of cholecystokinin. A considerable increase in activity was observed in the jejunum after the hormone, whereas there was no response in the distal duodenum. Absence of reaction in the proximal duodenum and an increase in the motility in the distal ileum has previously been demonstrated after cholecystokinin administration. It is concluded that the human duodenum differs from the rest of the small intestine in its reaction to cholecystokinin. The change in reaction appears to occur on a level with the ligament of Treitz.