Effects of hydergine on pancreatic exocrine secretion in the isolated, blood-perfused pancreas of the dog

Abstract

The effects of hydergine on the secretion of pancreatic juice in the dog were investigated in preparations of the isolated, blood-perfused pancreas, and compared with those of secretin and dopamine. Hydergine (30-300 micrograms) injected intra-arterially caused dose-dependent increases in the secretion of pancreatic juice after a delay of a few min. The secretory activity of 300 micrograms of hydergine was approximately equal to that of 0.05 units of secretin and 2 micrograms of dopamine. Secretory responses to hydergine were inhibited by treatment with sulpiride, but not inhibited by phentolamine, propranolol, atropine or metiamide. The concentration of bicarbonate in the pancreatic juice induced by hydergine was increased in a dose-dependent manner. However, the protein concentration was scarcely changed. These secretory actions were analogous to those of dopamine. From these results, it is concluded that hydergine mainly stimulates pancreatic secretion by acting on dopaminergic receptors of the dog pancreas.