Contribution of vagal afferents to respiratory reflexes evoked by acute inhalation of ozone in dogs

Journal Article · Sat May 01 00:00:00 EDT 1993 · Journal of Applied Physiology (1985); (United States)

OSTI ID:6279363

Schelegle, E S; Carl, M L; Coleridge, H M; Coleridge, J C; Green, J F ^[1]

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1. Univ. of California, Davis (United States)

Acute inhalation of ozone induces vagally mediated rapid shallow breathing and bronchoconstriction. In spontaneously breathing anesthetized dogs, we attempted to determine whether afferent vagal C-fibers in the lower airways contributed to these responses. Dogs inhaled 3 ppm ozone for 40-70 min into the lower trachea while cervical vagal temperature was maintained successively at 37, 7, and 0 degrees C. At 37 degrees C, addition of ozone to the inspired air decreased tidal volume and dynamic lung compliance and increased breathing frequency, total lung resistance, and tracheal smooth muscle tension. Ozone still evoked significant effects when conduction in myelinated vagal axons was blocked selectively by cooling the nerves to 7 degrees C. Ozone-induced effects were largely abolished when nonmyelinated vagal axons were blocked by cooling to 0 degree C, breathing during ozone inhalation at 0 degree C being generally similar to that during air breathing at 0 degree C, except that minute volume and inspiratory flow were higher. We conclude that afferent vagal C-fibers in the lower airways make a major contribution to the acute respiratory effects of ozone and that nonvagal afferents contribute to the effects that survive vagal blockade.

• OSTI ID: 6279363
• Journal Information: Journal of Applied Physiology (1985); (United States), Vol. 74:5; ISSN 8750-7587
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
DOGS
BLOOD PRESSURE
RESPIRATION
OZONE
BIOLOGICAL EFFECTS
VAGUS
COOLING
RESPONSE MODIFYING FACTORS
ACUTE EXPOSURE
INHALATION
NERVES
TRACHEA
ANIMALS
AUTONOMIC NERVOUS SYSTEM
INTAKE
MAMMALS
NERVOUS SYSTEM
RESPIRATORY SYSTEM
VERTEBRATES
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