Pyruvate dehydrogenase activation in inactive muscle during and after maximal exercise in men

Pyruvate dehydrogenase activity (PDHa) and acetyl-group accumulation were examined in the inactive deltoid muscle in response to maximal leg exercise in men. Seven subjects completed three consecutive 30-s bouts of maximal isokinetic cycling, with 4-min rest intervals between bouts. Biopsies of the deltoid were obtained before exercise, after bouts 1 and 3, and after 15 min of rest recovery. Inactive muscle lactate (LA) and pyruvate (PYR) contents increased more than twofold ( P < 0.05) after exercise ( bout 3) and remained elevated after 15 min of recovery ( P < 0.05). Increased PYR accumulation secondary to LA uptake by the inactive deltoid was associated with greater PDHa, which progressively increased from 0.71 ± 0.23 mmol ⋅ min−1⋅ kg wet wt−1at rest to a maximum of 1.83 ± 0.30 mmol ⋅ min−1⋅ kg wet wt−1after bout 3( P < 0.05) and remained elevated after 15 min of recovery (1.63 ± 0.24 mmol ⋅ min−1⋅ kg wet wt−1; P < 0.05). Acetyl-CoA and acetylcarnitine accumulations were unaltered. Increased PDHaallowed and did not limit the oxidation of LA and PYR in inactive human skeletal muscle after maximal exercise.

Pyruvate dehydrogenase activation in inactive muscle during and after maximal exercise in men Journal Articles