Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

To investigate how the ventilatory response to isocapnic hypoxia is modified by steady-state exercise, five subjects were studied at rest and performing 70 W bicycle exercise. At rest, isocapnic hypoxia (end-tidal PO2 50 Torr) for 25 min resulted in a biphasic response: an initial increase in ventilation was followed by a subsequent decline (HVD). During exercise, an end-tidal PO2 of 55-60 Torr was used. The magnitude of the initial ventilatory response to isocapnic hypoxia was increased from a mean +/ SE of 1.43 +/- 0.323 L/min per % arterial desaturation at rest to 2.41 +/- 0.424 L/min per % during exercise (P less than 0.05), but the magnitude of the HVD was reduced from 0.851 +/- 0.149 L/min per % at rest to 0.497 +/- 0.082 L/min per % during exercise (P less than 0.05). The ratio of HVD to the acute hypoxia response was reduced from 0.696 +/- 0.124 at rest to 0.202 +/- 0.029 during exercise (P less than 0.01). We conclude that while exercise augments the ventilatory sensitivity to hypoxia, it also has a direct effect on the mechanisms by which sustained hypoxia depresses peripheral chemosensitivity.

Original publication

DOI

10.1016/0034-5687(91)90109-v

Type

Journal article

Journal

Respir Physiol

Publication Date

12/1991

Volume

86

Pages

393 - 404

Keywords

Adult, Carbon Dioxide, Chemoreceptor Cells, Exercise, Humans, Hypoxia, Male, Oxygen, Respiration