MANSOOR, J. K., M. W. ELDRIDGE, K. Y. YONEDA, E. S. SCHELEGLE, and S. C. WOOD. Role of airway receptors in altitude-induced dyspnea. Med. Sci. Sports Sci., Vol. 33, No. 9, 2001, pp. 1449–1455.
Purpose: The purpose of this study was to examine the role of airway receptors in respiratory-related sensations after ascent to altitude.
Methods: Ratings of respiratory-related sensations, perceived exertion and acute mountain sickness, heart rate, and peripheral oxygen saturation were recorded at rest and exercise in male and female subjects who had inhaled either aerosolized saline or saline with tetracaine after acute ascent to an altitude of 3500 m and after prolonged acclimatization of 18 d at altitudes between 4000 and 5000 m.
Results: Tetracaine had no effect on respiratory-related sensations at altitude either at rest or during exercise, and male and female subjects experienced similar respiratory-related sensations. Sensations of rapid breathing were experienced at rest after acute exposure to 3500 m as compared with sea level, but not after acclimatization to 5000 m. Sensations of rapid breathing, air hunger, and heavy breathing were experienced during exercise after acute and prolonged altitude exposure as compared with sea level, with a sensation of chest tightness experienced at 3500 m and a sensation of gasping experienced at 5000 m.
Conclusion: These results suggest that airway afferents play no role in the respiratory-related sensations experienced by male and female subjects either during acute ascent to altitude or after prolonged acclimatization at altitude.
Physical Therapy Department, School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA; National Institute of Environmental Health Sciences, Research Triangle Park, NC; Center for Environmental Medicine and Lung Biology, University of North Carolina, Chapel Hill, NC; Department of Medicine, Division of Pulmonary and Critical Care Medicine, School of Medicine, University of California, Davis, Davis, CA; Department of Veterans Affairs, VA Northern California Health Care System, Martinez, CA; Department of Anatomy, Cell Biology and Physiology, School of Veterinary Medicine, University of California, Davis, Davis, CA; and Summa Health System Foundation, Akron, OH.