Postpranial Glucose Metabolism Flashcards Preview

Jonathan's Metabolism > Postpranial Glucose Metabolism > Flashcards

Flashcards in Postpranial Glucose Metabolism Deck (18):
1

How much of the pancreas is for endocrine function?

1-2 %, from the islets of Langerhans

2

What are the major exocrine products of the pancreas?

bicarbonate, amylase, trypsin, chymotrypsin, carboxypeptidase

3

What are the four types of cells in islets of Langerhans

beta-cells for insulin/amylin
alpha-cells for glucagon
delta-cells for somatostatin
theta (phi)-cells for pancreatic polypeptide

4

Insulin preprohormone is cut into peptides by _____?

endopeptidase
prohormone converter 2 - between pre and pro
prohormone converter 1 between pro and insulin

5

T/F Insulin gene has a lot of mutations associated during evolution

False, the gene is highly conserved

6

What are the two distinct phases of insulin secretion?

1st sharpe rise in secretion
2nd prolonged secretion phase

7

Describe the cellular event leading to insulin secertion

Glut 2 channel allowing glucose entry, leading to production of ATP and shuts ATP-gated K+ channels, allowing the opening of Ca2+ channels, and downstream enzymic action

8

T/F amino acids trigger the insulin pathway in similar fashion as glucose

True, except amino acids directly enter the TCA cycle

9

T/F More insulin gets released when glucose is administered intravenously

False, more is released with oral intake of glucose

10

Where is incretin secreted? What is the trigger of its release?

in the gut
triggered by nutrients: glucose, fatty acids, amino acids

11

T/F Proglucagon gives rise to glucagon is the gut

False, it gives rise to glucagon in the pancreas, an GLP-1 in the gut

12

Where is glucagon-like peptide secreted?

form the L-cells of small intestine

13

What is the function of GLP?

binding to beta cells to stimulate proinsulin production
also blocks gastric emptying
inhibit glucagon secretion
promote beta-cell growth

14

GLP has great therapeutic use for diabetes. Why isn't it used?

It has a very short half life

15

What is Exenatide?

it's a GLP-1 mimetic for treating diabetes

16

What is the function of GIP

stimulate insulin release and lipoprotein lipase activity for fat clearance

17

Amylin is co-secreted with insulin. What is its function?

inhibit glucagon secretion
delay gastic emptying
inhibit food intake

18

What is the amylin replacement drug?

Pramlintide