Induction of transient airway hyperresponsiveness by exposure to 4 ppm nitrogen dioxide in guinea pigs

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of Toxicology and Environmental Health; (United States)

DOI:https://doi.org/10.1080/15287399209531683· OSTI ID:7120295

Kobayashi, T; Shinozaki, Y ^[1]

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1. National Inst. for Environmental Studies, Ibaraki (Japan)

In the present study, we investigated (1) whether airway responsiveness to inhaled histamine-aerosol could be induced during 7-d exposure of guinea pigs to 4 ppm NO[sub 2] and, if so, (2) whether thromboxane A2 may be involved in such increase. Female Hartley guinea pigs were divided into 6 groups (n = 15/group). Three groups were exposed to filtered air and the other 3 groups were exposed to NO[sub 2] for 1, 3, or 7 d (24 h/d). Baseline specific airway resistance (SRaw) did not change significantly after exposure to 4 ppm NO[sub 2] or air. Airway responsiveness was determined 1 wk before the beginning of exposure and on the day of termination of the exposure. Prior to exposure to NO[sub 2], the EC200His, the concentrations of inhaled histamine necessary to double SRawNaCl (SRaw after inhalation of 0.9% NaCl), were 1.07 [plus minus] 0.20, 1.30 [plus minus] 0.20, and 1.01 [plus minus] 0.18 mM for the 3 groups later given NO[sub 2] for 1, 3, and 7 d, respectively. Following exposure to NO[sub 2] for 1, 3, or 7 d, EC200His values were 1.42 [plus minus] 0.25, 0.66 [plus minus] 0.10 (p < .05), and 1.05 [plus minus] 0.22 mM, respectively. These results show that 7-d exposure to 4 ppm NO[sub 2] induced a significant increase in airway responsiveness on d 3. Exposure to air had no significant effect on the airway responsiveness. This transient hyperresponsiveness was inhibited by a specific inhibitor of thromboxane synthetase, OKY 046. These results indicated that (1) a lower concentration (4 ppm) of NO[sub 2] than that previously reported can induce transient hyperresponsiveness in guinea pigs during appropriate long-term exposure, and (2) thromboxane A2 may play an important role in this transient airway hyperresponsiveness.

• OSTI ID: 7120295
• Journal Information: Journal of Toxicology and Environmental Health; (United States), Journal Name: Journal of Toxicology and Environmental Health; (United States) Vol. 37:3; ISSN 0098-4108; ISSN JTEHD6
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism &amp; Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR POLLUTION
AMINES
ANIMALS
ASTHMA
AZOLES
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BODY
BRONCHI
CARBOXYLIC ACID SALTS
CHALCOGENIDES
CHRONIC EXPOSURE
COMPARATIVE EVALUATIONS
DISEASES
EVALUATION
GUINEA PIGS
HETEROCYCLIC COMPOUNDS
HISTAMINE
IMIDAZOLES
INHALATION
INTAKE
INTRATRACHEAL ADMINISTRATION
LUNGS
MAMMALS
METHACRYLATES
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
POLLUTION
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
RODENTS
SENSITIVITY
VERTEBRATES