Endo - Insulin/Glucagon Flashcards
C-peptide
released in 1:1
half life 3 - 4x longer than insulin
used as a measure of insulin secretory capacity
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
basal insulin levels
down lipolysis down proteolysis down glycogenolysis (want to hold onto stores)
amylin actions
down appetite
down rate of gastric emptying
insulin secretion (early phase)
early: initial burst of insulin in the first 10 min after a meal due to fusion of docked granules
insulin secretion (late phase)
slower rise of insulin release (mobilize from reserve pool)
insulin stim
Hyperglycemia
AAs, FAs
Incretins (GIP,GLP-1, Gastrin, Secretin)
Ach (Parasympathetic)
insulin inhibition
SS
NE
E
insulin: oral vs injection
greater response by oral due to incretins that stim insulin secretion (GIP, gastrin, secretin, GLP-1)
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
when does ketosis occur
when virtually no effective insulin available
present –> FFA –> VLDL + TG
absent –> FFA –> ketones
diabetes mellitus mech
absolute or relative deficiency of insulin
absolute or relative excess of glucagon
diabetes mellitus Sx
hyperglycemia
polyuria
polydipsia
polyphagia
obesity and insulin resistance
TNF-alpha (from adipose) and IL-6 (macs)
angry fat - release inflammatory - interfere w/ IRS-associated insulin signaling
insulin response for normal vs diabetic
normal: peak around 60 min
diabetes: peak around 120 min - wider
