EFFECT OF CHOLECYSTOKININ-OCTAPEPTIDE AND ATROPINE ON HUMAN COLONIC MOTILITY, TONE, AND TRANSIT

The role of cholecystokinin (CCK) in postprandial control of colonic m otility is controversial. To test the hypothesis that CCK stimulates c olonic tone, motility, and transit we measured these colonic functions in 16 healthy subjects using intraluminal manometry, barostatic ballo on measurements, and radioscintigraphy. This was a randomized-order, d ouble-blind, sequential study design in each subject of saline and eit her atropine (0.01 mg/kg stat and 0.01 mg/kg/hr by infusion) or CCK-oc tapeptide (OP, 30 ng/kg stat and 60 ng/kg/hr by infusion). Atropine wa s used as control to demonstrate responsiveness of selected parameters of colonic motility. Atropine significantly reduced whole colon (chan ge from fasting = 52 +/- 11%) and left colon (change from fasting 61 /- 8%) phasic pressure activity and transverse colon tone (change from fasting 159 +/- 40%); CCK-OP had no significant effects on phasic con tractility, tone or transit. Thus, a CCK-OP infusion that maximally st imulates pancreatic exocrine secretion and gallbladder contraction has no effect on motor function or transit in prepared colon of healthy s ubjects.