Effect of acute hyperglycemia on basal and bombesin-stimulated pancreaticobiliary secretion in humans

This study was undertaken to investigate the effect of acute hyperglycemia on basal and bombesin-stimulated pancreaticobiliary secretion. Seven healthy subjects participated in two experiments performed in random order during normoglycemia and hyperglycemic clamping at 15 mM. Duodenal outputs of bilirubin, trypsin, amylase, and bicarbonate were measured by aspiration with a recovery marker under basal conditions for 60 min and during continuous infusion of bombesin (1 ng/kg x min) for 60 min. Plasma cholecystokinin (CCK) and pancreatic polypeptide (PP) levels were determined at regular intervals. Compared to normoglycemia, during hyperglycemia basal outputs of bilirubin (17 +/- 3 vs. 0.9 +/- 0.4 micromol/60 min), trypsin (24 +/- 4 vs. 4 +/- 1 U/60 min), amylase (12 +/- 1 vs. 3 +/- 1 kU/60 min), and bicarbonate (2.9 +/- 0.5 vs. 1.2 +/- 0.2 mmol/60 min) were significantly p < 0.05) reduced. Bombesin significantly (p < 0.05) increased pancreaticobiliary output during both normo- and hyperglycemia. During hyperglycemia bombesin-stimulated 60-min outputs of bilirubin, trypsin, amylase, and bicarbonate were not significantly different compared to those during normoglycemia. Basal and bombesin-stimulated plasma PP concentrations were significantly (p < 0.05) reduced during hyperglycemia, but plasma CCK levels were not significantly different. It is concluded that acute hyperglycemia reduces basal but does not affect bombesin-induced pancreaticobiliary secretion.