28 Gastrointestinal hormones Flashcards
Gastrin - source?
G-cells in antrum of stomach
Gastrin - stimulated by?
Amino acids Vagal input (acetylcholine) Calcium ETOH Antral distention pH > 3.0
Gastrin - inhibited by?
pH <3.0
Somatostatin
Secretin
CCK
Gastrin - target cells?
Parietal cells
Chief cells
Gastrin - effect?
Increased HCL
Increased intrinsic factor
Increased pepsinogen secretion
Omeprazole - MOA
Blocks H/K ATPase of parietal cells
Causes decreased H+ release
Somatostatin - source?
D cells in antrum of stomach
Somatostatin - Stimulation?
Acid in duodenum
Somatostatin - Target?
Everything - the great inhibitor
Somatostatin - response?
Inhibits gastrin release
Inhibits HCl release
Inhibits release of insulin glucagon, secretin and motilin
Increases pancreatic and biliary output
CKK - source?
I cells of duodenum
CKK - stimulation?
AA and Fatty acid chains
CKK - effect?
Gallbladder contraction
Relaxation of sphincter of Oddi
Increased pancreatic enzyme secretion
Secretin - source?
S cells of duodenum
Secretin - stimulation?
Fat, bile, pH <4.0
Secretin - inhibition?
pH >4.0, gastrin
Secretin - response?
Increased pancreatic HCO3 release
Inhibits gastrin release
Inhibits HCl release
How does the gastrin-response to Secretin change in a gastrinoma?
Secretin causes increased gastrin release (normal is inhibition)