Flashcards in L76: Pancreas Deck (37)
What's the ""islets of langerhans"
Endocrine pancreas - 3 major cell types. Minority of pancreatic mass.
Majority of cells. Digestive enzymes and secretions.
What do epsilon cells secrete?
What do delta cells secrete?
What do beta cells secrete?
What do PP cells secrete?
What does pancreatic polypeptide do?
inhibits acinar cells via paracrine action
What is amylin?
Synergizes with insulin. Can create plaques if built up in stressed out B-cells
C-peptide half life?
35 min. Good indicator of pancreatic function.
Good indicator of pancreatic function
Why is cleavage of C-peptide critical?
exposes end of insulin chain that interacts with receptor
What glucose transporter is on the Beta-cell?
What is the "glucose sensor" of the beta-cell?
What senses ATP from glucose metabolism in B-cell, promoting closure of K+ channels?
What kind of drugs act on SUR to close the K+ channel, and promote insulin release?
What promotes vesicle (of insulin) release at B-cell?
What inhibits insulin release at B-cell?
What potentiates insulin release at B-cell?
FFA/aa's (increase ATP through oxidation), and GLP1 (Incretin)
Describe the nature of insulin release
Insulin binds what type of receptor?
Which GLUT is insulin dependent
What two pathways does the insulin receptor promote
1. Increase GLUT4 installation
2. Increase growth/mitogenetic actions
What 4 factors does pro-glucagon consist of?
GRPP, glucagon, GLP-1, GLP-2
What happen to GRPP-Glucagon in the pancreatic islet cell?
Cleaved to GRPP + glucagon (Active peptides)
T/F: glucagon phosphorylates the bifunctional enzyme
True, it phosphorylates the enzyme, conferring PHOSPHATASE activity. Dephosphorylation of downstream enzymes promotes gluconeogenesis.
T/F: insulin dephosphorylates the bifunctional enzyme
T: insulin dephosphorylates the bifunctional enzyme, conferring KINASE activity. Phosphorylation of the downstream enzymes promotes glycolysis
What inhibits hepatic ketogenesis
Can insulin inhibit glucagon secretion at the alpha-cell?
Can glucagon inhibit insulin secretion at the b-cell?
What promotes hepatic ketogenesis?
SS14 (delta cells)
suppresses insulin release
Synergistic with insulin regulation of blood glucose
Contributes to amyloid formation in beta-cell
Inverse correlation with ghrelin and
What two hormones have a permissive effect on gluconeogenesis and lipolysis?
GH and cortisol
Ghrelin has what effect on hypothalamus?