Plasma cholecystokinin levels and gallbladder volumes after proctocolectomy with ileal pouch-anal anastomosis.

BACKGROUND The colon and rectum contain regulatory peptides in mucosal endocrine cells, which suggests a hormonal role. In animal studies colectomy leads to increased plasma levels of cholecystokinin. Little is known about the effects of proctocolectomy with ileal pouch-anal anastomosis on the release of cholecystokinin in human beings. Therefore we studied the effects of this procedure on fasting, postprandial, and bombesin-stimulated plasma cholecystokinin levels and gallbladder volumes. METHODS Ten patients who had undergone proctocolectomy with ileal pouch-anal anastomosis and 12 healthy volunteers participated in the study. Fasting and postprandial plasma cholecystokinin levels and gallbladder 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 with ileal pouch and five healthy volunteers. RESULTS Fasting plasma cholecystokinin levels were higher (p < 0.05) in patients with ileal pouch-anal anastomosis (2.6 +/- 0.3 pmol/L) compared with controls (1.7 +/- 0.2 pmol/L). Integrated postprandial plasma cholecystokinin levels were also distinctly higher (p < 0.01) in patients (978 +/- 126 pmol/L.180 min) than in controls (588 +/- 60 pmol/L.180 min). Mean fasting gallbladder volume was significantly (p < 0.01) decreased in patients with ileal pouch-anal anastomosis (18 +/- 2 ml) compared with controls (28 +/- 2 ml). Postprandial gallbladder emptying as measured by percentage 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 pmol/L.20 min). CONCLUSIONS Fasting, postprandial, and bombesin-stimulated plasma cholecystokinin levels are elevated in patients with ileal pouch-anal anastomosis compared with controls. Fasting gallbladder volume is decreased after ileal pouch-anal anastomosis. These findings suggest that the colon contains a factor that inhibits the release of cholecystokinin.