Pancreas Flashcards
What is the function of Sulfonylurea (Tolbutamide & Glyburide) drugs?
They promote the closing of ATP -dependent K+ channels –> increasing insulin release. used in the treatment of typeII diabetes
A linear increase in insulin secretion begins at what concentration of plasma glucose?
85 mg/dL
In diabetic patients what is the first phase to dissapear?
The acute phase of insulin release
What enzymes are upregulated via insulin release? In the liver and B-cells?
1) Hexokinase (phosphorylating glucose), PFK, Pyruvate dehydrogenase {Glycolysis} 1B) Glycogen synthase (increasing glycogen stores) 2) Glucokinase
Insulin stimulates the uptake of TGs via what?
Lipoprotein lipase
Insulin is an inhibitor of what enzyme, in regards to TG breakdown?
Hormone Sensitive Lipase
What effect does insulin have on K+ uptake into the cells?
It increases the uptake K+ into the cells
What effect does a-adrenergic agonists have on insulin release?
Inhibits insulin release
What is seen in regards to protein breakdown in patients w/ T1D?
Increased breakdown of proteins; including increased levels of Urea formed
What are the levels of total body and plasma K+ in patients w/ T1D?
1A) Total Body: K+, decreased (D/t polyuria) 1B) Plasma K+, increased. (D/t lack of insulin’s affect on the Na+/K+ ATPase, not being able to pump K+ into the cell)
What are the three causes for obesity induced insulin resistance?
1) Decreased GLUT-4 uptake of glucose in response to insulin release 2) Decreased ability of insulin to repress hepatic glucose production 3) Inability of insulin to repress hormone-sensitive lipase (HSL) or increase lipoprotein lipase (LPL) in adipose tissue
Via what mechanism can Type II DM occur in non obese patients?
Via decreased release of insulin from the pancreas; varying degrees of insulin resistance can also occur
When insulin binds to its receptor it initiates a process of autophosphyrlation. This activates ____ which can activate the downstream products of ___ & ______ for initiation of metabolic effects and _____ for growth effects
1) Activates: IRS 1-4
2) Metabolic Effects: PI3K & PKB/AKT
3) Growth Effects: MAPK
What are two main metabolic effects mediated via insulin binding to an insulin receptor?
1) Translocation of GLUT 4 receptors
2) Activatoin of Protein Phosphatases (activating more enzymes)
GLUT 4 translocation to the cell membrane via insulin binding to its receptor and upregulation of what downstream product?
PI3K
Glucagon promotes gluconeogenesis via inhibiting the production of what two products?
1) Fructose 2-6 diphosphate
2) Conversion of Phenolpyruvate to Pyruvate
