Endocrine Pancreas Pathology Flashcards
What are the features of islets of langerhans?
Discrete cell clusters consisting of endocrine cells with specific functions; vascular (reflecting endocrine function); predominate in the pancreas neck and tail
What is glucose homeostasis regulated by?
Hepatic release of glucose, tissue utilization of glucose, hormonal control of glucose by insulin and glucagon (amongst others)
What is the regulation of insulin release?
- GLUT2 takes glucose into beta cells;
- Glucose metabolism generates ATP;
- ATP inhibits the membrane K channel;
- Depolarization results in Ca influx;
- Ca influx results in insulin release
How is insulin processed?
Pro-insulin is cleaved in the beta cell to form insulin and C-peptide; C peptide is a marker of endogenous insulin (can differentiate from insulin administered as a pharm agent)
What effect does insulin have on adipose tissue?
Increases glucose uptake and lipogenesis; decreases lipolysis
What effect does insulin on skeletal M?
Increased glucose uptake, glycogen synthesis, and protein synthesis
What effect does insulin have on the liver?
Decreased gluconeogenesis; increased glycogen synthesis and lipogenesis
What are the incretins?
Includes GLP1 and glucose-dependent insulin releasing polypeptide (GIP)
What is the MOA of incretins?
Stimulate insulin release and inhibit glucagon release resulting in lower blood glucose
What are incretins inactivated by?
DPP4
What A1C value is considered pre-DM?
5.7-6.4
What A1C value is considered diabetic?
> 6.5
What FPG value indicates DM?
> 126
What OGTT (2 hour) and RPG value indicates diabetes?
> 200
An A1c value of 5 is equivalent to what estimated average glucose value?
97 mg/dL
