Postprandial gut peptide plasma levels in women with idiopathic slow- transit constipation

Background: As abnormalities of circulating gut regulatory peptides may have pathogenetic relevance in chronic idiopathic slow-transit constipation, we measured fasting and postprandial levels of plasma pancreatic polypeptide, motilin, cholecystokinin, neurotensin, and somatostatin in women with the disease. Results were compared with those of women with normal bowel habits. Methods: Eight women with slow-transit constipation and 10 healthy women were studied. Blood samples were taken at regular intervals in fasting conditions and for 3 h after a standard solid-liquid meal (550 kcal). Gut peptide plasma levels were measured with a radioimmunoassay. Results: Fasting gut peptide levels and postprandial pancreatic polypeptide responses were normal in constipated patients, in whom, however, motilin levels did not increase after the meal, and postprandial concentration-time curves of cholecystokinin, neurotensin, and somatostatin were delayed. Mean ± standard error of the mean peak times in patients and in controls were, respectively, 99 ± 14.7 and 46 ± 4.1 min (P <0.01, Mann-Whitney test) for cholecystokinin, 135 ± 9.8 and 60 ± 3.9 min (P <0.01) for neurotensin, and 111 ± 17.7 and 51 ± 6.0 min (P <0.05) for somatostatin. Conclusions: Patients with slow-transit constipation have abnormal postprandial patterns of motilin, cholecystokinin, neurotensin, and somatostatin.