Endo - Insulin/Glucagon Flashcards Preview

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Flashcards in Endo - Insulin/Glucagon Deck (17):
1

C-peptide

released in 1:1
half life 3 - 4x longer than insulin
used as a measure of insulin secretory capacity

2

insulin receptors

contain tyrosine kinase
2 alpha, 2 beta
autophos (amplify and prolong)
+ phosphorylates cytoplasmic IRS-1 and IRS-2
can be internalized and degraded

3

basal insulin levels

down lipolysis
down proteolysis
down glycogenolysis
(want to hold onto stores)

4

amylin actions

down appetite
down rate of gastric emptying

5

insulin secretion (early phase)

early: initial burst of insulin in the first 10 min after a meal due to fusion of docked granules

6

insulin secretion (late phase)

slower rise of insulin release (mobilize from reserve pool)

7

insulin stim

Hyperglycemia
AAs, FAs
Incretins (GIP,GLP-1, Gastrin, Secretin)
Ach (Parasympathetic)

8

insulin inhibition

SS
NE
E

9

insulin: oral vs injection

greater response by oral due to incretins that stim insulin secretion (GIP, gastrin, secretin, GLP-1)

10

glucose transporters

GLUT-1/3: transport @ low glucose
GLUT-2: transport @ high glucose. Pancreatic beta and hepatic
GLUT-4: sk muscle, heart and adipose (reg by insulin)
GLUT-5: brush border of SI. transport frutctose

11

when does ketosis occur

when virtually no effective insulin available
present --> FFA --> VLDL + TG
absent --> FFA --> ketones

12

diabetes mellitus mech

absolute or relative deficiency of insulin
absolute or relative excess of glucagon

13

diabetes mellitus Sx

hyperglycemia
polyuria
polydipsia
polyphagia

14

obesity and insulin resistance

TNF-alpha (from adipose) and IL-6 (macs)
angry fat - release inflammatory - interfere w/ IRS-associated insulin signaling

15

insulin response for normal vs diabetic

normal: peak around 60 min
diabetes: peak around 120 min - wider

16

causes of insulin resistance

abnormal B-cell secretory product
circulating insulin antagonists
target tissue defects

17

glucagon synthesis

preproglucagon
proglucagon
glucagon (or GLP-1 in intestinal)