PLASMA CHOLECYSTOKININ LEVELS AND GALLBLADDER VOLUMES AFTER PROCTOCOLECTOMY WITH ILEAL POUCH-ANAL ANASTOMOSIS

Background. The colon and rectum contain regulatory peptides in mucosa l endocrine cells, which suggests a hormonal role. In animal studies c olectomy leads to increased plasma levels of cholecystokinin. Little i s known about the effects of proctocolectomy with ileal pouch-anal ana stomosis on the release of cholecystokinin in human beings. Therefore we studied the effects of this procedure on fasting, postpranadial, an d bombesin-stimulated plasma cholecystokinin levels and gallbladder vo lumes. Methods. Ten patients who had undergone protocolectomy with ile al pouch-anal anastomosis and 12 healthy volunteers participated in th e study. Fasting and postprandial plasma cholecystokinin levels and ga llbladder volumes were studied for 3 hours at 15-minute intervals. In a second experiment plasma cholecystokinin levels were measured before and during intravenous. administration of bombesin in six patients wi th ileal pouch and five healthy volunteers. Results. Fasting plasma ch olecystokinin levels were higher (p < 0.05) in patients with ileal pou ch-anal anastomosis (2.6 +/- 0.3 pmol/L) compared with controls (1.7 /- 0.2 pmol/L. Integrated postprandial plasma cholecystokinin levels w ere also distinctly higher (p < 0.01) in patients (978 +/- 126 pmol/L . 180 min) than in controls (588 +/- 60 pmol/L . 180 min). Mean fastin g gallbladder volume was significantly (p < 0.01) decreased in patient s with ileal pouch-anal anastomosis (18 +/- 2 ml) compared with contro ls (28 +/- 2 ml). Postprandial gallbladder emptying as measured by per centage change was similar in both groups. After infusion of bombesin, integrated plasma cholecystokinin responses were higher (p < 0.05) in patients (161 +/- 20 pmol/L . 20 min) than in controls (90 +/- 12 pmo l/L . 20 min). Conclusions. Fasting, postprandial, and bombesin-stimul ated plasma cholecystokinin levels are elevated in patients with ileal pouch-anal anastomosis compared with controls. Fasting gallbladder vo lume is decreased after ileal pouch-anal anastomosis. These findings s uggest that the colon contains a factor that inhibits the release of c holecystokinin.