Dose-response relationship of ozone-induced airway hyperresponsiveness in unanesthetized guinea pigs

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Journal of Toxicology and Environmental Health; (USA)

DOI:https://doi.org/10.1080/15287399009531416· OSTI ID:6703569

Nishikawa, M; Suzuki, S; Ikeda, H; Fukuda, T; Suzuki, J; Okubo, T ^[1]

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1. Yokohama City Univ. School of Medicine (Japan)

The effect of ozone dose (the product of ozone concentration and exposure time) on airway responsiveness was examined in unanesthetized, spontaneously breathing guinea pigs. Airway responsiveness was assessed by measuring specific airway resistance (sRaw) as a function of increasing concentration of inhaled methacholine (Mch) aerosol (the concentration of Mch required in order to double the baseline sRaw: PC200Mch). The airway responsiveness was measured before and at 5 min, 5 h, and 24 h after exposure. A 30-min exposure to 1 ppm ozone (dose 30 ppm.min) did not change PC200Mch at any time after exposure. Both a 90-min exposure to 1 ppm ozone and a 30-min exposure to 3 ppm ozone, which are identical in terms of ozone dose (90 ppm.min), decreased PC200Mch to a similar degree. A 120-min exposure to 3 ppm ozone (360 ppm.min) produced a much greater decrease of PC200Mch at 5 min and 5 h after exposure, compared with low-dose exposure. There was a significant correlation between ozone dose and the change in airway responsiveness. In all groups, the baseline sRaw was increased by approximately 50% at 5 min after exposure, but there was no correlation between the changes in PC200Mch and the baseline sRaw. This study suggests that ozone-induced airway hyperresponsiveness in guinea pigs is closely related to ozone dose.

• OSTI ID: 6703569
• Journal Information: Journal of Toxicology and Environmental Health; (USA), Journal Name: Journal of Toxicology and Environmental Health; (USA) Vol. 30:2; ISSN JTEHD; ISSN 0098-4108
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROSOLS
AIR POLLUTION
ANIMALS
COLLOIDS
DISPERSIONS
DOSE-RESPONSE RELATIONSHIPS
GUINEA PIGS
MAMMALS
OZONE
POLLUTION
RESPIRATORY SYSTEM
RODENTS
SENSITIVITY
SOLS
TOXICITY
VERTEBRATES