Postpranial Glucose Metabolism Flashcards Preview

Jonathan's Metabolism > Postpranial Glucose Metabolism > Flashcards

Flashcards in Postpranial Glucose Metabolism Deck (18)
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1
Q

How much of the pancreas is for endocrine function?

A

1-2 %, from the islets of Langerhans

2
Q

What are the major exocrine products of the pancreas?

A

bicarbonate, amylase, trypsin, chymotrypsin, carboxypeptidase

3
Q

What are the four types of cells in islets of Langerhans

A

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

4
Q

Insulin preprohormone is cut into peptides by _____?

A

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

5
Q

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

A

False, the gene is highly conserved

6
Q

What are the two distinct phases of insulin secretion?

A

1st sharpe rise in secretion

2nd prolonged secretion phase

7
Q

Describe the cellular event leading to insulin secertion

A

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
Q

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

A

True, except amino acids directly enter the TCA cycle

9
Q

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

A

False, more is released with oral intake of glucose

10
Q

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

A

in the gut

triggered by nutrients: glucose, fatty acids, amino acids

11
Q

T/F Proglucagon gives rise to glucagon is the gut

A

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

12
Q

Where is glucagon-like peptide secreted?

A

form the L-cells of small intestine

13
Q

What is the function of GLP?

A

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

14
Q

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

A

It has a very short half life

15
Q

What is Exenatide?

A

it’s a GLP-1 mimetic for treating diabetes

16
Q

What is the function of GIP

A

stimulate insulin release and lipoprotein lipase activity for fat clearance

17
Q

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

A

inhibit glucagon secretion
delay gastic emptying
inhibit food intake

18
Q

What is the amylin replacement drug?

A

Pramlintide