Effect of octapeptide of cholecystokinin on canine pyloric pressure.

ISENBERG, JON I., AND ATTILA CSENDES. Efect of octapeptide of cholecystokinin on canine pyloric pressure. Am. J. Physiol. 222(2) : 42843 1. 1972.-Intraluminal pressure was measured in five dogs with gastric and duodenal cannulas. Open-tipped perfused tubes were used as pressure sensors. To localize the pylorus (i.e., gastroduodenal junction), transluminal potential difference was recorded. The sensors were moved in l-cm increments, at 15-set intervals, back and forth across the pylorus. On separate days the C-terminal octapeptide of cholecystokinin (0.25, 0.5, and 1.0 pg/ kg-hr) was infused intravenously. NaCl, 0.15 M, infused alone served as the control. Mean (&SE) resting pyloric pressure when the sensors were moved from stomach to duodenum was 14.8 =t 1 .O cm HzO. When they were moved from duodenum to stomach, it was 8.9 & 0.9 cm HZO. The higher doses of the octapeptide of cholecystokinin (0.5 and 1.0 pg/kg-hr) produced an increase in p yloric pressure. Mean sphincter length was 1.8 cm. It is concluded that the dog pylorus was tonic and that the resting tone was increased by intravenous infusion of the C-terminal octapeptide of cholecystokinin.