Insulin physiology

Question 1

Does insulin cross placenta?

Answer 1

No

Question 2

Preproinsulin synthesized where?

Answer 2

RER

Question 2

Name the glucose transporter:

adipose, striated muscle

Insulin dependent?

Answer 2

GLUT-4

Yes

Question 2

Describe the intracellular mechanism by which glucose entry into beta cell stimulates insulin release

Answer 2

Glucose enters through GLUT-4

Glycolysis generates ATP

ATP-sensitive K channel closes

Membrane depolarizes and Ca enters scell

Increase in intracellular Ca stimulates insulin exocytosis

Question 4

Insulin receptor is what kind of receptor

Answer 4

tyrosine kinase

Question 5

Name the glucose transporter:

spermatocytes, GI tract

Insulin dependent?

Answer 5

GLUT-5

No

Question 6

Name the glucose transporter:

beta islet cells, liver, kidney, intestine

Insulin dependent?

Answer 6

GLUT-2

No

Question 7

Name the glucose transporter:

RBC, brain, cornea

Insulin dependent?

Answer 7

GLUT 1

No

Question 9

Pt workup demonstrates elevated insulin and elevated C peptide: organic or factitious?

Answer 9

organic

Question 10

Name the glucose transporter:

brain

Insulin dependent?

Answer 10

GLUT-3

No

Question 11

Effect of growth hormone on insulin release

Answer 11

Increases it