Airway smooth muscle responsiveness from dogs with airway hyperresponsiveness after O/sub 3/ inhalation

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · J. Appl. Physiol.; (United States)

OSTI ID:6834728

Jones, G L; O'Byrne, P M; Pashley, M; Serio, R; Jury, J; Lane, C G; Daniel, E E

Airway hyperresponsiveness occurs after inhalation of O3 in dogs. The purpose of this study was to examine the responsiveness of trachealis smooth muscle in vitro to electrical field stimulation, exogenous acetylcholine, and potassium chloride from dogs with airway hyperresponsiveness after inhaled O3 in vivo and to compare this with the responsiveness of trachealis muscle from control dogs. In addition, excitatory junction potentials were measured with the use of single and double sucrose gap techniques in both groups of dogs to determine whether inhaled O3 affects the release of acetylcholine from parasympathetic nerves in trachealis muscle. Airway hyperresponsiveness developed in all dogs after inhaled O3 (3 ppm for 30 min). The acetylcholine provocative concentration decreased from 4.11 mg/ml before O3 inhalation to 0.66 mg/ml after O3 (P less than 0.0001). The acetylcholine provocative concentration increased slightly after control inhalation of dry room air. Airway smooth muscle showed increased responses to both electrical field stimulation and exogenous acetylcholine but not to potassium chloride in preparations from dogs with airway hyperresponsiveness in vivo. The increased response to electrical field stimulation was not associated with a change in excitatory junctional potentials. These results suggest that a postjunctional alteration in trachealis muscle function occurs after inhaled O3 in dogs, which may account for airway hyperresponsiveness after O3 in vivo.

• Research Organization: McMaster Univ., Hamilton, Ontario (Canada)
• OSTI ID: 6834728
• Journal Information: J. Appl. Physiol.; (United States), Journal Name: J. Appl. Physiol.; (United States) Vol. 65:1; ISSN JAPYA
• Country of Publication: United States
• Language: English

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560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETYLCHOLINE
ALKALI METAL COMPOUNDS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL EFFECTS
CHLORIDES
CHLORINE COMPOUNDS
CONTRACTION
DOGS
DRUGS
ELECTRIC FIELDS
ESTERS
HALIDES
HALOGEN COMPOUNDS
INHALATION
INTAKE
MAMMALS
MUSCLES
NEUROREGULATORS
ORGANIC COMPOUNDS
OZONE
PARASYMPATHOMIMETICS
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
QUATERNARY COMPOUNDS
RESPIRATORY SYSTEM
TRACHEA
VERTEBRATES