Enhanced release of cholecystokinin by soya-bean trypsin inhibitor in chickens

Whether ingestion of soya-bean trypsin inhibitor (SBTI) alters the release of cholecystokinin (CCK) was investigated in chickens. A meal of an adequate diet supplemented with SBTI (0, 100, or 1000 mg/kg) was given through a stomach tube, followed by CCK determination with specific CCK-8 antibody. The plasma CCK level increased from a basal level (control diet) of 9.6 +/- 0.6 to 13.4 +/- 0.6 and 18.1 +/- 0.8 fmol/ml plasma at 90 min after feeding the diet supplemented with 100 and 1000 mg SBTI, respectively. Since the SBTI supplementation did not affect crop emptying rates significantly, it was concluded that SBTI by itself enhanced CCK release into circulation in a dose-dependent fashion.