Comparative study of plasma pancreatic polypeptide responses to food, secretin, and bombesin in normal subjects and in patients with chronic pancreatitis.

Plasma pancreatic polypeptide (PP) responses to food, secretin (1 CU/kg, intravenous) and bombesin (60 pmol/kg/20 min intravenous) were compared in 14 normal subjects and in 17 patients with chronic pancreatitis and pancreatic insufficiency. Basal plasma PP concentrations were significantly higher in normal subjects than in patients with chronic pancreatitis, but there was considerable overlap between the groups. Ingestion of food induced significant increases in plasma PP both in normal subjects and in patients with chronic pancreatitis, whereas secretin and bombesin significantly increased plasma PP levels in normal subjects only. The PP responses to the three stimuli were significantly larger in normal subjects than in patients with chronic pancreatitis, but there was marked overlap. Calculation of the peak to basal plasma PP ratio did not result in better discrimination between the two groups. In normal subjects there were no significant correlations between the PP responses to the three stimuli, whereas in patients with chronic pancreatitis these responses were significantly correlated. Furthermore, in patients with chronic pancreatitis the PP responses to the various stimuli were significantly correlated with the basal plasma PP level.