Absorptive & Postabsorptive Nutrient Utilization II Flashcards
define post-absorptive phase
NO current nutrient supply
what happens regarding glc during post-absorptive phase?
glc absorption stops
blood glc decreases to stim glucagon and inhibit insulin secretion
during post-absorptive phase, liver switches from glc ___ to glc ___
utilization to production
what’s the main brain fuel during post-absorptive phase?
glc
decreasing levels of glc will stim ___ secretion from liver
glucagon
glucagon stim ___ in the liver
glycogenolysis
how long does glycogen depot last?
8-12 hours at rest/moderate exercise
30 min at high demand/major exercise
glucagon stim ___ in adipose tissue
lipolysis
what do epinephrine and norepinephrine do in adipose tissue during post-absorptive phase?
stim lipolysis and FA release through beta-adrenoreceptors
what (from the heart) stim lipolysis during post-absorptive, specifically exercise?
natriuretic peptide
what stim lipolysis after and during prolonged exercise?
growth hormone
cortisol
how are FA mobilized and released from adipose tissue?
hormone sensitive lipase (HSL)
what does hormone sensitive lipase do?
activated by norepi and glucagon
helps mobilize FA for release from adipose
what’s used for ketone body and VLDL synthesis?
NEFA
NEFA circulates as ____, bound to ___, and packaged in VLDL
free FA
bound to albumin
why are there multiple different FA transport mechanisms?
albumin can saturate during rapid adipose tissue mobilization
albumin can decrease during long phases of nutrient deficiency
VLDL are independent from AA availability
what does CD36 do regarding FA transport?
translocates NEFA into cells
what is CD36?
membrane protein found on cell surfaces
fatty acid translocase
___ is translocated during absorptive phase following glc and FA uptake, whereas ___ is translocated during post-absorptive
absorptive - GLUT4
post-absorptive - CD36
what does LOW serum insulin do regarding muscles/protein during post-absorptive?
diminished aa entry into muscle pool
glc entry declines, net protein degradation and use of aa pool for energy
the insulin/glucagon ratio in the ___ determines action of antagonistic enzyme pairs
liver
during post-absorptive phase, glucagon ___ (deactivates) glycogensynthase and phosphofructokinase
phsophorylates