Inhibition of human gastric lipase by intraduodenal fat involves glucagon-like peptide-1 and cholecystokinin

Seven healthy volunteers were intubated with two double lumen nasogastric t ubes, one in the stomach, the other in the duodenum. This system allows sim ultaneous sampling of gastric juice and separate intraduodenal perfusion wi th a dietary fat (fish oil, 1269 kJ). Gastrin-17 was infused i.v. at a rate of 40 pmol/kg/h throughout the study. Gastric lipase was measured at 15-mi n intervals as activity (tributyrin) and as immunoreactivity (ELISA). Infus ion of gastrin-17 resulted in a stable increase in the plasma concentration from a basal concentration of 8.3+/-0.8 pmol/l to 41.4+/-4.2 pmol/l. Perfu sion with fat reduced gastric lipase activity from 24.2+/-5.3 to 7.2+/-2.5 kU/l (P < 0.05), and immunoreactivity from 0.7+/-0.1 to 0.42+/-0.1 mg/l (P < 0.05). After termination of fat perfusion, gastric lipase secretion incre ased again, though not reaching preinhibitory concentrations. During the in traduodenal perfusion with fat the plasma concentrations of glucagon-like p eptide-1 (GLP-1) and cholecystokinin (CCK) increased from 6.9+/-0.5 to 15.1 +/-1.5 pmol/l (P < 0.05) and from 1.2+/-0.4 to 3.8+/-0.9 pmol/l (P < 0.05). This study reveals a negative effect of fat in the duodenum on gastric lip ase secretion. This effect may be mediated by GLP-1 and/or CCK, (C) 1999 El sevier Science B.V. All rights reserved.