Comparison of subcutaneous and intravenous administration of pancreatic stimulants

In conscious dogs with permanent gastric and pancreatic fistulas, the response to single injections of extracts of mucosa of the gastrointestinal tract by intravenous and subcutaneous routes was compared. Both crude and highly purified secretin preparations were weak stimulants of the pancreas by subcutaneous administration, in contrast to the large effect of the same doses given intravenously. An extract containing pancreozymin was effective in causing increased protein secretion by the pancreas by both routes of injection. Gastrin stimulated pancreatic volume flow by subcutaneous administration but not by intravenous administration, in contrast to secretin. This indicates that crude extracts of the mucosa of the pyloric gland area of the hog do not contain enough secretin to be easily detectable. Attempts to show that supramaximal doses of secretin, pancreozymin, and gastrin exhibit self-inhibitory properties when tested on pancreatic secretion were unsuccessful, although self-inhibition of gastrin-stimulated gastric secretion was confirmed.