TY - JOUR
T1 - Effect of acetazolamide on respiratory muscle fatigue in humans
AU - Gonzales, Joaquin U.
AU - Scheuermann, Barry W.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/1/5
Y1 - 2013/1/5
N2 - Previous studies have demonstrated that carbonic anhydrase inhibition with acetazolamide reduces exercise capacity. The mechanism responsible for this early fatigue is unclear, but may be partly mediated by impaired respiratory muscle function. Inspiratory muscle strength and endurance were assessed in seven healthy men (age 28±5yrs, ±SD) by measuring maximal inspiratory pressure (MIP) and time to task failure during a constant-load breathing test (CLBT), respectively, under control (CON) and acetazolamide (ACZ; 500mg/8h po for 3 days) conditions that were separated by two weeks and randomized between subjects. In addition, MIP was measured before and after moderate-intensity cycling exercise to fatigue while pulmonary gas exchange, plasma pH, and ventilation were measured during exercise. ACZ did not alter pulmonary function (FVC, FEV1, MVV) or MIP measured at rest (CON, -157±47 vs. ACZ, -154±45cmH2O, p>0.05), but decreased time to task failure during the CLBT (CON, 1340±820 vs. ACZ, 698±434s; p=0.01). Exercise duration during cycling exercise was reduced (p=0.003) with ACZ (1090±254s) compared to CON (1944±532s) in the presence of a significantly lower plasma pH and higher ventilation compared to control (p<0.05). Compared to resting values, MIP was reduced (p=0.03) in ACZ but not CON at exhaustion. In conclusion, carbonic anhydrase inhibition with ACZ is associated with impaired respiratory muscle function at rest and following constant load cycling which may contribute to reduced exercise tolerance with carbonic anhydrase inhibition.
AB - Previous studies have demonstrated that carbonic anhydrase inhibition with acetazolamide reduces exercise capacity. The mechanism responsible for this early fatigue is unclear, but may be partly mediated by impaired respiratory muscle function. Inspiratory muscle strength and endurance were assessed in seven healthy men (age 28±5yrs, ±SD) by measuring maximal inspiratory pressure (MIP) and time to task failure during a constant-load breathing test (CLBT), respectively, under control (CON) and acetazolamide (ACZ; 500mg/8h po for 3 days) conditions that were separated by two weeks and randomized between subjects. In addition, MIP was measured before and after moderate-intensity cycling exercise to fatigue while pulmonary gas exchange, plasma pH, and ventilation were measured during exercise. ACZ did not alter pulmonary function (FVC, FEV1, MVV) or MIP measured at rest (CON, -157±47 vs. ACZ, -154±45cmH2O, p>0.05), but decreased time to task failure during the CLBT (CON, 1340±820 vs. ACZ, 698±434s; p=0.01). Exercise duration during cycling exercise was reduced (p=0.003) with ACZ (1090±254s) compared to CON (1944±532s) in the presence of a significantly lower plasma pH and higher ventilation compared to control (p<0.05). Compared to resting values, MIP was reduced (p=0.03) in ACZ but not CON at exhaustion. In conclusion, carbonic anhydrase inhibition with ACZ is associated with impaired respiratory muscle function at rest and following constant load cycling which may contribute to reduced exercise tolerance with carbonic anhydrase inhibition.
KW - Carbonic anhydrase
KW - Diamox
KW - Exercise tolerance
KW - Maximal inspiratory pressure
KW - Respiratory muscle function
UR - http://www.scopus.com/inward/record.url?scp=84871922999&partnerID=8YFLogxK
U2 - 10.1016/j.resp.2012.08.023
DO - 10.1016/j.resp.2012.08.023
M3 - Article
C2 - 23017330
AN - SCOPUS:84871922999
VL - 185
SP - 386
EP - 392
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
SN - 1569-9048
IS - 2
ER -