PMID- 16670154
OWN - NLM
STAT- MEDLINE
DCOM- 20060926
LR  - 20211203
IS  - 0193-1849 (Print)
IS  - 0193-1849 (Linking)
VI  - 291
IP  - 3
DP  - 2006 Sep
TI  - Carbohydrate ingestion does not alter skeletal muscle AMPK signaling during 
      exercise in humans.
PG  - E566-73
AB  - There is evidence that increasing carbohydrate (CHO) availability during exercise 
      by raising preexercise muscle glycogen levels attenuates the activation of 
      AMPKalpha2 during exercise in humans. Similarly, increasing glucose levels 
      decreases AMPKalpha2 activity in rat skeletal muscle in vitro. We examined the 
      effect of CHO ingestion on skeletal muscle AMPK signaling during exercise in nine 
      active male subjects who completed two 120-min bouts of cycling exercise at 65 
      +/- 1% V(O2 peak). In a randomized, counterbalanced order, subjects ingested 
      either an 8% CHO solution or a placebo solution during exercise. Compared with 
      the placebo trial, CHO ingestion significantly (P < 0.05) increased plasma 
      glucose levels and tracer-determined glucose disappearance. Exercise-induced 
      increases in muscle-calculated free AMP (17.7- vs. 11.8-fold), muscle lactate 
      (3.3- vs. 1.8-fold), and plasma epinephrine were reduced by CHO ingestion. 
      However, the exercise-induced increases in skeletal muscle AMPKalpha2 activity, 
      AMPKalpha2 Thr(172) phosphorylation and acetyl-CoA Ser(222) phosphorylation, were 
      essentially identical in the two trials. These findings indicate that AMPK 
      activation in skeletal muscle during exercise in humans is not sensitive to 
      changes in plasma glucose levels in the normal range. Furthermore, the rise in 
      plasma epinephrine levels in response to exercise was greatly suppressed by CHO 
      ingestion without altering AMPK signaling, raising the possibility that 
      epinephrine does not directly control AMPK activity during muscle contraction 
      under these conditions in vivo.
FAU - Lee-Young, Robert S
AU  - Lee-Young RS
AD  - Dept. of Physiology, The University of Melbourne, Carlton, Victoria, Australia.
FAU - Palmer, Matthew J
AU  - Palmer MJ
FAU - Linden, Kelly C
AU  - Linden KC
FAU - LePlastrier, Kieran
AU  - LePlastrier K
FAU - Canny, Benedict J
AU  - Canny BJ
FAU - Hargreaves, Mark
AU  - Hargreaves M
FAU - Wadley, Glenn D
AU  - Wadley GD
FAU - Kemp, Bruce E
AU  - Kemp BE
FAU - McConell, Glenn K
AU  - McConell GK
LA  - eng
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
DEP - 20060502
PL  - United States
TA  - Am J Physiol Endocrinol Metab
JT  - American journal of physiology. Endocrinology and metabolism
JID - 100901226
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 0 (Insulin)
RN  - 0 (Multienzyme Complexes)
RN  - 020IUV4N33 (Phosphocreatine)
RN  - 33X04XA5AT (Lactic Acid)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - 9005-79-2 (Glycogen)
RN  - EC 2.7.11.1 (Protein Serine-Threonine Kinases)
RN  - EC 2.7.11.31 (AMP-Activated Protein Kinases)
RN  - EC 6.4.1.2 (Acetyl-CoA Carboxylase)
RN  - X4W3ENH1CV (Norepinephrine)
RN  - YKH834O4BH (Epinephrine)
SB  - IM
MH  - AMP-Activated Protein Kinases
MH  - Acetyl-CoA Carboxylase/metabolism
MH  - Adenosine Triphosphate/metabolism
MH  - Adult
MH  - Blood Glucose/drug effects
MH  - Carbohydrate Metabolism/drug effects
MH  - Dietary Carbohydrates/*pharmacology
MH  - Epinephrine/blood
MH  - Exercise/*physiology
MH  - Glycogen/metabolism
MH  - Humans
MH  - Insulin/blood
MH  - Kinetics
MH  - Lactic Acid/blood/metabolism
MH  - Lipid Metabolism/drug effects
MH  - Male
MH  - Multienzyme Complexes/*metabolism
MH  - Muscle, Skeletal/*metabolism
MH  - Norepinephrine/blood
MH  - Oxidation-Reduction
MH  - Oxygen Consumption/drug effects/physiology
MH  - Phosphocreatine/metabolism
MH  - Phosphorylation/drug effects
MH  - Protein Serine-Threonine Kinases/*metabolism
MH  - Pulmonary Gas Exchange/drug effects/physiology
EDAT- 2006/05/04 09:00
MHDA- 2006/09/27 09:00
CRDT- 2006/05/04 09:00
PHST- 2006/05/04 09:00 [pubmed]
PHST- 2006/09/27 09:00 [medline]
PHST- 2006/05/04 09:00 [entrez]
AID - 00023.2006 [pii]
AID - 10.1152/ajpendo.00023.2006 [doi]
PST - ppublish
SO  - Am J Physiol Endocrinol Metab. 2006 Sep;291(3):E566-73. doi: 
      10.1152/ajpendo.00023.2006. Epub 2006 May 2.