Muscle metabolism during heavy-intensity exercise after acute acetazolamide administration

Barry W. Scheuermann, John M. Kowalchuk, Donald H. Paterson, Albert W. Taylor, Howard J. Green

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7 Citations (Scopus)

Abstract

Carbonic anhydrase (CA) inhibition is associated with a lower plasma lactate concentration ([La-](pl)), but the mechanism for this association is not known. The effect of CA inhibition on muscle high-energy phosphates [ATP and phosphocreatine (PCr)], lactate ([La-](m)), and glycogen was examined in seven men [28 ± 3 (SE) yr] during cycling exercise under control (Con) and acute CA inhibition with acetazolamide (Acz; 10 mg/kg body wt iv). Subjects performed 6-min step transitions in work rate from 0 W to a work rate corresponding to ~50% of the difference between the O2 uptake at the ventilatory threshold and peak O2 uptake. Muscle biopsies were taken from the vastus lateralis at rest, at 30 min postinfusion, at end exercise (EE), and at 5 and 30 min postexercise. Arterialized venous blood was sampled from a dorsal hand vein and analyzed for [La-](pl). ATP was unchanged from rest values; no difference between Con and Acz was observed. The fall in PCr from rest [72 ± 3 and 73 ± 3.6 (SE) mmol/kg dry wt for Con and Acz, respectively] to EE (51 ± 4 and 46 ± 5 mmol/kg dry wt for Con and Acz, respectively) was similar in Con and Acz. At EE, glycogen (mmol glucosyl units/kg dry wt) decreased to similar values in Con and Acz (307 ± 16 and 300 ± 19, respectively). At EE, no difference was observed in [La-](m) between conditions (46 ± 6 and 43 ± 5 mmol/kg dry wt for Con and Acz, respectively). EE [La-](pl) was higher during Con than during Acz (11.4 ± 1.0 vs. 8.2 ± 0.6 mmol/l). The similar [La-](m) but lower [La-](pl) suggests that the uptake of La- by other tissues is enhanced after CA inhibition.

Original languageEnglish
Pages (from-to)722-729
Number of pages8
JournalJournal of Applied Physiology
Volume88
Issue number2
Publication statusPublished - Feb 1 2000

Keywords

  • Carbonic anhydrase
  • High-energy phosphates
  • Muscle lactate
  • Plasma lactate

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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  • Cite this

    Scheuermann, B. W., Kowalchuk, J. M., Paterson, D. H., Taylor, A. W., & Green, H. J. (2000). Muscle metabolism during heavy-intensity exercise after acute acetazolamide administration. Journal of Applied Physiology, 88(2), 722-729.