Possible Interaction: Glucagon and Secretin

“Gastrointestinal hormones secretin , CCK-PZ, gastrin, and serotonin) modulate the glucose- and amino acids–induced secretions of insulin and glucagon , respectively.”

“In the small bowel, CCK, gastrin, motilin, VIP, and glucagon stimulate contractions, while secretin inhibits contractions.”

“ Secretin had a faint effect upon the adenylyl cyclase activity and glucagon was completely inefficient at this level.”

“ Secretin was 100-fold less effective as a competitor and glucagon competed poorly even at concentrations 10 000 times greater than that of the tracer molecule.”

“ Secretin , which, in the dog, has been reported to inhibit normal glucagon secretion, provoked a twofold increase in 3,500 dalton plasma glucagon concentration.”

“Caerulein, however, failed to increase inhibition when glucagon and secretin were infused simultaneously.”

“The highest degree of inhibition was obtained by the combination of glucagon and secretin.”

“W. P. Dyck and colleagues5 in 1970 found that, while an intravenous injection of just under 1 mg ofglucagon did not affect the resting output of pancreatic juice in man, it did inhibit the flow of juice stimulated by an infusion of pancreozymin and secretin.”

“However, the addition of glucagon to secretin showed additive effects on glycogenolysis.”

“The inhibitory effect of glucagon on pancreatic exocrine secretion induced by endogenously released secretin was studied in 4 dogs with chronic pancreatic fistulas and open gastric fistulas.”

“ Glucagon is structurally related to secretin but inhibits the effects of secretin and cholecystokinin (CCK) on pancreatic secretion in vivo.”