Isoprenaline and the pancreas in dogs.

1. In conscious dogs basal pancreatic secretion per 100 min was significantly reduced by 0.75 microgram kg-1h-1 of isoprenaline. The expected spontaneous peaking was seen only after stopping the drug. 2. Following propranolol, the 100-min pancreatic secretion was less than control but greater than secretion after isoprenaline. The interpeak interval was increased, and the perigee levels (interpeak) were higher than in the controls. Peak protein secretion was unaltered but volume was reduced. 3. Guanethidine did not abolish periodicity but it prolonged the interpeak interval. Protein peaks and 100-min totals were lower than control and volume perigees higher. 4. It is concluded that beta-adrenoreceptor stimulation inhibits pancreatic secretion. Adrenergic antagonists exert similar inhibitory effects indicating a complex role for the sympathetic nervous system in the control of pancreatic secretion.