Hormonal regulation of intermediary metabolism Flashcards
1
Q
five hormones that oppose insulin
A
- glucagon
- catecholamines
- glucocorticoids
- GH
- hormones of the gut
2
Q
cleavage of proinsuline yields?
A
insulin and C-peptide
3
Q
Things that stimulate insulin
A
- high glucose
- glucagon, cortisol
- FAs and ketones
- gut peptide hormones
- K+
- obesity
- catecholamines
4
Q
mechanism of insulin action
A
- binds to a transmembrane cell surface receptor
- receptor functions as tyrosine kinase
- phosphorylation of key docking proteins (IRS and Shc)
5
Q
where is GLUT4 expressed?
A
muscle and adipose
6
Q
insulin actions on muscle?
A
- stimulation of glucose transport into cell
- glycogen synthesis
- amino acid uptake
- protein synthesis
- inhibition of proteolysis
7
Q
insulin actions on adipose?
A
- glucose uptake
- fat synth
- LPL activation
- inhibition of HSL
- AA uptake
8
Q
insulin action on liver?
A
- does not affect glucose uptake because of GLUT2
- glucokinase and glycogen synthase activity
- glycolysis
- inhibition of gluconeogenesis
- FA synth
9
Q
FAs and AAs in relation to insulin and glucagon
A
- both stimulate insulin
- on the other hand, AAs stimulate glucagon while FAs inhibit glucagon
10
Q
major stimulus of insulin
A
high blood glucose
11
Q
major stimulus of glucagon
A
low blood glucose
12
Q
glucagon works on the….
A
liver only
13
Q
glucagon rapid actions on liver
A
- glycogenolysis
- inhibits glycogen synthetase
14
Q
glucagon slow actions on liver
A
- gluconeogenesis
- lipolysis
- inhibits FA synth
- hepatic ketogenesis
15
Q
two catecholamines
A
epinephrin and norepinephrin
