Influence of food on plasma cholecystokinin and gastrin in patients with partial gastric resections and Roux-en-Y anastomosis.

: Cholecystokinin (CCK) is a polypeptid released postprandially by the upper intestinal mucosa. There are several biological active forms of CCK. Radioimmunological measurements of CCK may not detect all biological active forms or may have the disadvantage of crossreacting with gastrin. In the following we describe a modification of a bioassay for CCK which was first developed by Liddle et al. (J Clin Invest 1985). By means of this bioassay pre- and postprandial plasma CCK-levels of healthy male volunteers are compared with CCK-levels of patients with partial gastric resections and excluded duodenum. Both groups showed similar basal CCK-values (about 1 pM) and a food induced increase of this hormone by reaching maximal values after 15 to 30 min (control: 4.30 +/- 0.65 vs. operated: 13.37 +/- 2.83 pM). Patients with gastric resections, however, had about three times more CCK released over the 60 min time period studied as compared to controls. Thus exclusion of the duodenum, the supposed main place of CCK production, does not cause a lower but rather higher increase of postprandial CCK release.