Mechanism of ozone-induced tachypneic response to hypoxia and hypercapnia in conscious dogs

Journal Article · Tue Jan 01 04:00:00 EST 1980 · J. Appl. Physiol.; (United States)

OSTI ID:6116595

Lea, L Y; Djokic, T D; Dumont, C; Graf, P D; Nadel, J A

In seven studies on three dogs exercising on a treadmill (1.6 km/h), we studied the effect of ozone on ventilatory responses to hypercapnia and to hypoxia. After ozone exposure (0.67 +- 0.02 ppM by vol; 2 h), the responses of minute volume of ventilation (VE) to progressive hypercapnia and hypoxia were not changed, but the breathing pattern in response to these stimuli changed. We analyzed the breathing pattern by plotting the relationship between VE and tidal volume (VT). During progressive hypercapnia, the slope of VE-VT relationship increased from a control value of 36.1 +- 1.6 (mean +- SE) to 93.5 +- 8.9 min-1 after ozone (n = 7, P less than 0.005); during hypoxia, the slope increased from a control value of 46.1 +- 8.6 to 142.7 +- 18.3 min-1 after ozone (n = 6, P less than 0.005). The ozone-induced tachypneic responses to hypercapnia and hypoxia were not affected by inhalation responses to hypercapnia and hypoxia were not affected by inhalation of atropine sulfate or isoproterenol aerosols, but were completely abolished by bilateral vagal blockade. These findings indicate an effect of ozone on the vagal receptors located in the airways and lungs that causes reflex tachypnea during hypercapnia and hypoxia.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 6116595
• Journal Information: J. Appl. Physiol.; (United States), Journal Name: J. Appl. Physiol.; (United States) Vol. 48:1; ISSN JAPYA
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL MODELS
BODY
DOGS
LUNGS
MAMMALS
ORGANS
OZONE
PATHOLOGICAL CHANGES
PHYSIOLOGY
RECEPTORS
RESPIRATION
RESPIRATORY SYSTEM
TOXICITY
VERTEBRATES