Beta-adrenergic blockade and metabo-chemoreflex contributions to exercise capacity
| Autor: | Agnieszka Ciarka, Robert Naeije, Georges Niset, Jean-François Argacha, Philippe van de Borne, Gaël Deboeck, Sofia Beloka, Dionysios Adamopoulos, Marko Gujic |
|---|---|
| Přispěvatelé: | Cardiology, Clinical sciences, Cardio-vascular diseases |
| Rok vydání: | 2008 |
| Předmět: |
Adult
Male Sympathetic nervous system medicine.medical_specialty Sympathetic Nervous System Adolescent Adrenergic beta-Antagonists Physical Therapy Sports Therapy and Rehabilitation Physical exercise Placebos Young Adult Oxygen Consumption Double-Blind Method Internal medicine Exercise/physiology medicine Aerobic exercise Humans Orthopedics and Sports Medicine Muscle Skeletal Exercise Cardiopulmonary disease Cross-Over Studies Sympathetic Nervous System/drug effects business.industry Hemodynamics Autonomic nervous system medicine.anatomical_structure Hemodynamics/drug effects Bisoprolol Anesthesia Breathing Cardiology Muscle Skeletal/drug effects medicine.symptom Adrenergic beta-Antagonists/pharmacology business Cardiology and Cardiovascular Medicine Hypercapnia medicine.drug |
| Zdroj: | Medicine and science in sports and exercise. 40(11) |
| ISSN: | 1530-0315 |
| Popis: | Purpose: Exercise-induced dyspnea in patients with cardiopulmonary diseases may be related to sympathetic nervous system activation, with increased metabo- and/or chemosensitivities. Whether this mechanism plays a role in exercising normal subjects remains unclear. Methods: Muscle sympathetic nerve activity (MSNA), HR, ventilation (V[spacing dot above]E), O2 saturation (SpO2), and end-tidal PCO2 (PetCO2) were measured in 14 healthy young adults after 1 wk of [beta]1-receptor blockade with bisoprolol 5 mg[middle dot]d-1 versus placebo after a double-blind, placebo-controlled, randomized crossover design. The MSNA and the ventilatory responses to hyperoxic hypercapnia (7% CO2 in O2), [DELTA]V[spacing dot above]E/[DELTA]PetCO2, and isocapnic hypoxia (10% O2 in N2), [DELTA]V[spacing dot above]E/[DELTA]SpO2, and to an isometric muscle contraction followed by a local circulatory arrest (metaboreflex) were determined at rest followed by an incremental cardiopulmonary exercise test. Results: Bisoprolol did not change the V[spacing dot above]E and MSNA responses to hypercapnia, hyperoxia, or isometric muscle contraction or ischemia. Bisoprolol decreased maximum O2 uptake (P < 0.05), workload (P < 0.05), and HR (P < 0.0001) andboth V[spacing dot above]E/V[spacing dot above]O2 and V[spacing dot above]E/V[spacing dot above]CO2 slopes (P < 0.05). Conclusions: These results suggest that decreased aerobic exercise capacity after intake of [beta]-blockers is accompanied by decreased ventilation at any metabolic rate. However, this occurs without detectable change in the sympathetic nervous system tone or in metabo- or chemosensitivity and is therefore probably of hemodynamic origin. |
| Databáze: | OpenAIRE |
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