Effects of training status on PDH regulation in human skeletal muscle during exercise

TY - JOUR

T1 - Effects of training status on PDH regulation in human skeletal muscle during exercise

AU - Gudiksen, Anders

AU - Bertholdt, Lærke

AU - Stankiewicz, Tomasz

AU - Tybirk, Jonas

AU - Plomgaard, Peter Stendahl

AU - Bangsbo, Jens

AU - Pilegaard, Henriette

N1 - CURIS 2017 NEXS 213

PY - 2017/12/1

Y1 - 2017/12/1

N2 - Pyruvate dehydrogenase (PDH) is the gateway enzyme for carbohydrate-derived pyruvate feeding into the TCA cycle. PDH may play a central role in regulating substrate shifts during exercise, but the influence of training state on PDH regulation during exercise is not fully elucidated. The purpose of this study was to investigate the impact of training state on post-translational regulation of PDHa activity during submaximal and exhaustive exercise. Eight untrained and nine endurance exercise-trained healthy male subjects performed incremental exercise on a cycle ergometer: 40 min at 50% incremental peak power output (IPPO), 10 min at 65% (IPPO), followed by 80% (IPPO) until exhaustion. Trained subjects had higher (P < 0.05) PDH-E1α, PDK1, PDK2, PDK4, and PDP1 protein content as well as PDH phosphorylation and PDH acetylation. Exercising at the same relative intensity led to similar muscle PDH activation in untrained and trained subjects, whereas PDHa activity at exhaustion was higher (P < 0.05) in trained than untrained. Furthermore, exercise induced similar PDH dephosphorylation in untrained and trained subjects, while PDH acetylation was increased (P < 0.05) only in trained subjects. In conclusion, PDHa activity and PDH dephosphorylation were well adjusted to the relative exercise intensity during submaximal exercise. In addition, higher PDHa activity in trained than untrained at exhaustion seemed related to differences in glycogen utilization rather than differences in PDH phosphorylation and acetylation state, although site-specific contributions cannot be ruled out.

AB - Pyruvate dehydrogenase (PDH) is the gateway enzyme for carbohydrate-derived pyruvate feeding into the TCA cycle. PDH may play a central role in regulating substrate shifts during exercise, but the influence of training state on PDH regulation during exercise is not fully elucidated. The purpose of this study was to investigate the impact of training state on post-translational regulation of PDHa activity during submaximal and exhaustive exercise. Eight untrained and nine endurance exercise-trained healthy male subjects performed incremental exercise on a cycle ergometer: 40 min at 50% incremental peak power output (IPPO), 10 min at 65% (IPPO), followed by 80% (IPPO) until exhaustion. Trained subjects had higher (P < 0.05) PDH-E1α, PDK1, PDK2, PDK4, and PDP1 protein content as well as PDH phosphorylation and PDH acetylation. Exercising at the same relative intensity led to similar muscle PDH activation in untrained and trained subjects, whereas PDHa activity at exhaustion was higher (P < 0.05) in trained than untrained. Furthermore, exercise induced similar PDH dephosphorylation in untrained and trained subjects, while PDH acetylation was increased (P < 0.05) only in trained subjects. In conclusion, PDHa activity and PDH dephosphorylation were well adjusted to the relative exercise intensity during submaximal exercise. In addition, higher PDHa activity in trained than untrained at exhaustion seemed related to differences in glycogen utilization rather than differences in PDH phosphorylation and acetylation state, although site-specific contributions cannot be ruled out.

KW - Pyruvate dehydrogenase

KW - Skeletal muscle

KW - Acetylation

KW - Phosphorylation

KW - Exercise training

KW - Exercise

U2 - 10.1007/s00424-017-2019-6

DO - 10.1007/s00424-017-2019-6

M3 - Journal article

C2 - 28801776

SN - 0031-6768

VL - 469

SP - 1615

EP - 1630

JO - Pflügers Archiv - European Journal of Physiology

JF - Pflügers Archiv - European Journal of Physiology

IS - 12

ER -