Pharmacology: Incretin Effect and Physiology Flashcards
where does the word incretin come from
INtestinal seRCETion of INsulin
what are the 2 different types of incretin peptides and what are they released by
GIP = from K cells GLP-1 = from L cells
what are GIP and GLP-1 broken down by
DPP-IV
very short half life
what are incretin peptides released in response to
nutrient stimuli
what is the result of incretin peptide secretion
increased insulin secretion when high blood glucose
what pathway of insulin secretion do sulphonylureas act via of insulin secretion
Triggering pathway
what pathway of insulin secretion do incretins act via
Amplifying pathway
what receptor does the Amplifying pathway act via, and what does activation result in
the GLP-1/GIP receptor - G protein coupled receptor
results in increased cAMP
what effect does increased cAMP have on the pancreatic beta cell
close Katp channel, moderate Ca2+ currents, acts directly on insulin secretory mechanism
what needs to be activated in order for the Amplifying pathway to take effect
the Triggering pathway, which is triggered by glucose or sulphonylureas
what is the net result of the Amplifying pathway
primarily augmentation of insulin secretion
describe the Triggering and Amplifying pathway in terms of hypoglycaemia
Triggering = can occur Amplifying = no hypoglycaemia
what is the incretin effect
oral glucose induces greater insulin secretion than parental(non-gut) administration of IV glucose
what are the stimulatory nutrients for incretin hormones
glucose, amino acids, fatty acids
what is the principle incretin hormone and what is it secreted by
GLP-1, secreted by L cells in the gut
