External pancreatic secretion after bombesin infusion in man

The effect of bombesin on external pancreatic secretion was studied in 7 healthy volunteers and in 2 patients with a two thirds gastrectomy and a pancreatic fistula. After bombesin infusion (15 ng/kg/min), gastrin levels were significantly raised in all volunteers, but remained at basal levels in the gastrectomized patients. Bombesin was effective in stimulating pancreatic secretion in all patients. The volume of secretion increased two fold when compared with basal volume. Amylase and trypsin concentrations and outputs in the duodenal juice were greatly augmented (amylase concentration: basal, 70 dye U/ml; post bombesin, 620 dye U/ml. Amylase output: basal, 1000 dye U/15 min; post bombesin, 15,800 dye U/15 min). Secretin, when administered in conjunction with bombesin, partially inhibited its secretory effect. Bicarbonate secretion was slightly stimulated by bombesin, but at a very low level. A similar pattern of results was obtained in the 2 gastrectomized patients. In man, bombesin exerts an effect on pancreatic secretion that mimics the effect of CCK PZ, thus confirming the results obtained in the experimental animal. Gastrin does not play a fundamental role in this phenomenon.