Effect of acetazolamide on gas exchange and acid-base control after maximal exercise
Autor: | Norman L. Jones, J. M. Kowalchuk, George J. F. Heigenhauser, J. R. Sutton |
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Rok vydání: | 1992 |
Předmět: |
Adult
Male medicine.medical_specialty Physiology Acid–base homeostasis pCO2 chemistry.chemical_compound Lanthanum Physiology (medical) Internal medicine Carbonic anhydrase Respiration medicine Humans Exercise physiology Plasma Volume Exercise Acid-Base Equilibrium biology Pulmonary Gas Exchange Sodium Carbon Dioxide Hydrogen-Ion Concentration Acetazolamide Bicarbonates Endocrinology chemistry Biochemistry Carbon dioxide biology.protein Potassium Homeostasis medicine.drug |
Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 72(1) |
ISSN: | 8750-7587 |
Popis: | To investigate the interactions between the systems that contribute to acid-base homeostasis after severe exercise, we studied the effects of carbonic anhydrase inhibition on exchange of strong ions and CO2 in six subjects after 30 s of maximal isokinetic cycling exercise. Each subject exercised on two randomly assigned occasions, a control (CON) condition and 30 min after intravenous injection of 1,000 mg acetazolamide (ACZ) to inhibit blood carbonic anhydrase activity. Leg muscle power output was similar in the two conditions; peak O2 uptake (VO2) after exercise was lower in ACZ (2,119 +/- 274 ml/min) than in CON (2,687 +/- 113, P less than 0.05); peak CO2 production (VCO2) was also lower (2,197 +/- 241 in ACZ vs. 3,237 +/- 87 in CON, P less than 0.05) and was accompanied by an increase in the recovery half-time from 1.7 min in CON to 2.3 min in ACZ. Whereas end-tidal PCO2 was lower in ACZ than in CON, arterial PCO2 (PaCO2) was higher, and a large negative end-tidal-to-arterial difference (less than or equal to 20 Torr) was present in ACZ on recovery. In ACZ, postexercise increases in arterial plasma [Na+] and [K+] were greater but [La-] was lower. Arteriovenous differences across the forearm showed a greater uptake of La- and Cl- in CON than in ACZ. Carbonic anhydrase inhibition with ACZ, in addition to impairing equilibration of the CO2 system to the acid-base challenge of exercise, was accompanied by changes in equilibration of strong inorganic ions. A lowered plasma [La-] was not accompanied by greater uptake of La- by inactive muscle. |
Databáze: | OpenAIRE |
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