Affiliation:
1. Faculty of Kinesiology, University of Western Ontario, London, Canada.
Abstract
The interaction between systems regulating acid-base balance (i.e., CO2, strong ions, week acids) was studied in six subjects for 10 min after 30 s of maximal isokinetic cycling during control conditions (CON) and after 3 days of chronic acetazolamide (ChACZ) administration (500 mg/8 h po) to inhibit carbonic anhydrase (CA). Gas exchange was measured; arterial and venous forearm blood was sampled for acid-base variables. Muscle power output was similar in ChACZ and CON, but peak O2 intake was lower in ChACZ; peak CO2 output was also lower in ChACZ (2,207 +/- 220 ml/min) than in CON (3,238 +/- 87 ml/min). Arterial PCO2 was lower at rest, and its fall after exercise was delayed in ChACZ. In ChACZ there was a higher arterial [Na+] and lower arterial [lactate-] ([La-]) accompanied by lower arterial [K+] and higher arterial [Cl-] during the first part of recovery, resulting in a higher arterial plasma strong ion difference (sigma [cations] - sigma [anions]). Venoarterial (v-a) differences across the forearm showed a similar uptake of Na+, K+, Cl-, and La- in ChACZ and CON. Arterial [H+] was higher and [HCO3-] was lower in ChACZ. Compared with CON, v-a [H+] was similar and v-a [HCO3-] was lower in ChACZ. Chronic CA inhibition impaired the efflux of CO2 from inactive muscle and its excretion by the lungs and also influenced the equilibration of strong ions.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Cited by
18 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献