Secretion of gastric inhibitory polypeptide in patients with bile duct obstruction.

BACKGROUND

The direct contribution of bile to gastric inhibitory polypeptide (GIP) release and the role of bile in regulating GIP secretion in response to fat ingestion are still obscure. The present study was aimed to clarify the influence of bile on GIP release.

METHODS

Seven patients with obstruction of the common bile duct and nine volunteers participated in the study. Fifty milliliters of Lipomul was ingested, and GIP was measured serially for 180 min. After intraduodenal instillation of pooled autologous bile for 2 days, the same study was carried out.

RESULTS

The fat-stimulated GIP response was significantly lower in the patients than in the controls. The basal GIP level did not change on bile instillation, but the GIP response to fat ingestion was significantly increased on bile instillation compared with that in the absence of bile.

CONCLUSIONS

Intraluminal bile alone does not stimulate the secretion of GIP, but it promotes GIP secretion in response to fat ingestion.