Plasma Glucose: Insulin (lec 26)

Question 1

Primary regulatory hormones for plasma glucose?

Answer 1

insulin and glucagon

Question 2

Secretion of insulin determined by?

Goal of insulin?

Answer 2

abundance of nutrients (fed state) ->

insulin stores the excess as fuel (↓ plasma glu):
↑ glu oxyidation
↑ glycogen synth
↑ fat synth
↑ protein synth

Question 3

Secretion of glucagon determined by?

Goal of glucagon?

Answer 3

starvation (fast state) ->

mobilizes fuel (↑ plasma glu):
↑ glycogenolysis
↑ gluconeogenesis
↑ ketogenesis

Question 4

Insulin/Glucagon released from?

Answer 4

pancreas:
alpha cell -> glucagon
beta cells -> insulin

Question 5

Islet of Langerhans is?

Types of cells?

Answer 5

cluster of endocrine cells in pancreas

alpha -> glucagon
beta -> insulin
delta -> somatostatin

Question 6

Insulin synth?

Answer 6

Similar to peptide hormones:
preproinsulin ->
proinsulin ->
stored in granules

Question 7

Insulin secretory granules?

Answer 7

proinsulin cleaved into insulin/C-peptide

Question 8

Insulin route of secretion?

Answer 8

Glucose -> beta cells ->
ATP prdxn -> ↑ Ca2+ ->
insulin exocytosed

Question 9

Incretin Effect is?

Answer 9

ingested glucose ↑↑ insulin due to gut hormones

vs IV glu

Question 10

Insulin feedback regulation?

Answer 10

nutrients that stim insulin secretion are also disposed by insulin

Question 11

Insulin action on cell receptors?

Answer 11

insulin binds ⍺-recpt -> autophos β subunit -> activate tyrosine kinase/insulin receptor substrates (IRS)

Question 12

Gluconeogenesis is?

Answer 12

synth of new glucose (AA -> glucose)

Question 13

Glycogen synth is?

Answer 13

Δ glucose to glycogen for storage

Question 14

Glucose uptake is?

Answer 14

transport of glucose to tissues

Question 15

Oxidation is?

Answer 15

use of something for fuel (Δ glu to ATP)

Question 16

Glycogenolysis is?

Answer 16

breakdown of glycogen to glucose

Question 17

Tissue uptake of glu and AA stim by?

Answer 17

insulin

Question 18

Tissue release of glu, AA, FFA inhibited by?

Answer 18

insulin

Question 19

Insulin effect on liver: Carbs?

Answer 19

↑ glucose storage via:

↑ Δ glu to glycogen and fat
↓ gluconeogenesis

Question 20

Insulin effect on liver: Lipids?

Answer 20

1) ↑ syth/store fat and↓ fat oxydation

2) Release fats for store or use by skelet mm/adipose tissue

Question 21

Insulin effect on liver: Protein?

Answer 21

↑ prot synth

↓ prot degradation

Question 22

Insulin effect on skeletal mm?

Answer 22

principal site of glu disposal

↑ glu uptake (GLUT 4)
↑ glycogen synth
↑ glu oxy -> trigly formation
↑ protein synth
↓ protein degrad

Question 23

Insulin effect on adipose tissue?

Answer 23

↑ glu uptake (GLUT 4)
↑ glu -> FA
↑ trigly formation

Question 24

Insulin Receptor Substrates activate enzymes that do what?

Answer 24

GLUT 4 to membrane -> change glu to glycogen/lipids

upreg of protein synth in nucleus

Pull AA in -> protein synth