Action of secretin on pancreatic secretion

Abstract
Dogs with chronic duodenal fistulas were used for quantitative collections of pancreatic juice after single rapid injections of secretin and continuous intravenous administration of secretin. Measurement of volume and pH and analysis for bicarbonate and chloride, amylase, lipase, leucine aminopeptidase (LAP), glutamic oxalacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) were performed. Single rapid injections of secretin resulted in consistently reproducible responses on the same day. Apparent maximal stimulatory effect could not be achieved with single rapid injections of secretin even when quantities greater than that reported by others were used. Amylase concentrations were high after single rapid injections but fell off quickly suggesting a "washing out" effect. With continuous secretin stimulation after 120–180 min of collection, a fall in bicarbonate concentration and a rise in chloride concentration were obtained despite the maintenance of high volume. Exhaustion of pancreatic secretion was not achieved even after 12 hr of continuous intense stimulation. In one continuous experiment 23.8 ml pancreatic juice/10 min was obtained. GOT, GPT, and LAP were present sporadically in low variable concentrations.