Chronic exposure of rats to ozone and sulfuric acid aerosol: Biochemical and structural responses

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Groups of rats were exposed to either 0.12 or 0.20 ppm of ozone, 20, 100, or 150 ppm of sulfuric acid aerosol (04-0.8 pm diameter), or their mixtures in whole body exposure chambers for up to 90 days. Matched control animals were exposed to filtered air in comparable chambers. The rats were examined biochemically and morphometrically for centriacinar fibrosis or other indicators of pollutant-induced changes in the terminal bronchiole-alveolar duct junction region of the lung at the end of the exposures. By evaluating different markers of lung injury, we had previously demonstrated a synergistic interaction between ozone and sulfuric acid aerosol after acute exposures to these same concentrations of the pollutants. The present experiments were designed to answer the question of whether there was any interaction between ozone and respirable sized aerosols of sulfuric acid, synergistic or antagonistic, after chronic exposures. Exposure of rats to 0.12 or 0.20 ppm of ozone elicited tissue and cellular changes at the bronchiole-alveolar duct junction. Concurrent exposure to sulfuric acid aerosol did pot affect the extent or magnitude of these changes. Intermittent exposure (12 h per day) to ozone, with or without the acid aerosol, elicited a greater response than did continuous exposure (24 h per day). No consistent effects of exposure to sulfuric acid aerosol alone were observed, either morphometrically or biochemically. The biochemical data were consistent with the morphometric analyses, showing trends towards or significantly increased lung 4-hydroxyproline content in the rats exposed to ozone, with or without sulfuric acid aerosol, in the intermittent exposure experiment, but not after continuous exposure. No interactive effects between ozone and sulfuric acid aerosol were observed with any of the biochemical parameters examined. We conclude that ozone and sulfuric acid aerosols do not exhibit synergistic interactions after chronic exposures (90 days) of rats to the concentrations tested in this study, which correspond to concentrations showing synergistic interactions in previously performed acute studies. We also observed that exposure of rats to ozone for 12 h per day elicited greater lung changes, which we interpret to indicate a mild fibrotic response, than did exposure of rats for 24 h per day, whether or not there was accompanying exposure to the acid aerosol.

Original languageEnglish (US)
Pages (from-to)133-146
Number of pages14
JournalToxicology
Volume116
Issue number1-3
DOIs
StatePublished - Jan 15 1997

Fingerprint

Ozone
Aerosols
Rats
Bronchioles
Lung
Ducts
sulfuric acid
Acids
Hydroxyproline
Lung Injury
Animals
Fibrosis
Experiments
Air
Tissue

Keywords

  • Acid aerosols
  • Air pollution
  • Collagen
  • Lung
  • Morphometry
  • Ozone

ASJC Scopus subject areas

  • Toxicology

Cite this

Chronic exposure of rats to ozone and sulfuric acid aerosol : Biochemical and structural responses. / Last, Jerold A; Pinkerton, Kent E.

In: Toxicology, Vol. 116, No. 1-3, 15.01.1997, p. 133-146.

Research output: Contribution to journalArticle

@article{872835469dc14f24bdc13f780fc71b84,
title = "Chronic exposure of rats to ozone and sulfuric acid aerosol: Biochemical and structural responses",
abstract = "Groups of rats were exposed to either 0.12 or 0.20 ppm of ozone, 20, 100, or 150 ppm of sulfuric acid aerosol (04-0.8 pm diameter), or their mixtures in whole body exposure chambers for up to 90 days. Matched control animals were exposed to filtered air in comparable chambers. The rats were examined biochemically and morphometrically for centriacinar fibrosis or other indicators of pollutant-induced changes in the terminal bronchiole-alveolar duct junction region of the lung at the end of the exposures. By evaluating different markers of lung injury, we had previously demonstrated a synergistic interaction between ozone and sulfuric acid aerosol after acute exposures to these same concentrations of the pollutants. The present experiments were designed to answer the question of whether there was any interaction between ozone and respirable sized aerosols of sulfuric acid, synergistic or antagonistic, after chronic exposures. Exposure of rats to 0.12 or 0.20 ppm of ozone elicited tissue and cellular changes at the bronchiole-alveolar duct junction. Concurrent exposure to sulfuric acid aerosol did pot affect the extent or magnitude of these changes. Intermittent exposure (12 h per day) to ozone, with or without the acid aerosol, elicited a greater response than did continuous exposure (24 h per day). No consistent effects of exposure to sulfuric acid aerosol alone were observed, either morphometrically or biochemically. The biochemical data were consistent with the morphometric analyses, showing trends towards or significantly increased lung 4-hydroxyproline content in the rats exposed to ozone, with or without sulfuric acid aerosol, in the intermittent exposure experiment, but not after continuous exposure. No interactive effects between ozone and sulfuric acid aerosol were observed with any of the biochemical parameters examined. We conclude that ozone and sulfuric acid aerosols do not exhibit synergistic interactions after chronic exposures (90 days) of rats to the concentrations tested in this study, which correspond to concentrations showing synergistic interactions in previously performed acute studies. We also observed that exposure of rats to ozone for 12 h per day elicited greater lung changes, which we interpret to indicate a mild fibrotic response, than did exposure of rats for 24 h per day, whether or not there was accompanying exposure to the acid aerosol.",
keywords = "Acid aerosols, Air pollution, Collagen, Lung, Morphometry, Ozone",
author = "Last, {Jerold A} and Pinkerton, {Kent E}",
year = "1997",
month = "1",
day = "15",
doi = "10.1016/S0300-483X(96)03535-4",
language = "English (US)",
volume = "116",
pages = "133--146",
journal = "Toxicology",
issn = "0300-483X",
publisher = "Elsevier Ireland Ltd",
number = "1-3",

}

TY - JOUR

T1 - Chronic exposure of rats to ozone and sulfuric acid aerosol

T2 - Biochemical and structural responses

AU - Last, Jerold A

AU - Pinkerton, Kent E

PY - 1997/1/15

Y1 - 1997/1/15

N2 - Groups of rats were exposed to either 0.12 or 0.20 ppm of ozone, 20, 100, or 150 ppm of sulfuric acid aerosol (04-0.8 pm diameter), or their mixtures in whole body exposure chambers for up to 90 days. Matched control animals were exposed to filtered air in comparable chambers. The rats were examined biochemically and morphometrically for centriacinar fibrosis or other indicators of pollutant-induced changes in the terminal bronchiole-alveolar duct junction region of the lung at the end of the exposures. By evaluating different markers of lung injury, we had previously demonstrated a synergistic interaction between ozone and sulfuric acid aerosol after acute exposures to these same concentrations of the pollutants. The present experiments were designed to answer the question of whether there was any interaction between ozone and respirable sized aerosols of sulfuric acid, synergistic or antagonistic, after chronic exposures. Exposure of rats to 0.12 or 0.20 ppm of ozone elicited tissue and cellular changes at the bronchiole-alveolar duct junction. Concurrent exposure to sulfuric acid aerosol did pot affect the extent or magnitude of these changes. Intermittent exposure (12 h per day) to ozone, with or without the acid aerosol, elicited a greater response than did continuous exposure (24 h per day). No consistent effects of exposure to sulfuric acid aerosol alone were observed, either morphometrically or biochemically. The biochemical data were consistent with the morphometric analyses, showing trends towards or significantly increased lung 4-hydroxyproline content in the rats exposed to ozone, with or without sulfuric acid aerosol, in the intermittent exposure experiment, but not after continuous exposure. No interactive effects between ozone and sulfuric acid aerosol were observed with any of the biochemical parameters examined. We conclude that ozone and sulfuric acid aerosols do not exhibit synergistic interactions after chronic exposures (90 days) of rats to the concentrations tested in this study, which correspond to concentrations showing synergistic interactions in previously performed acute studies. We also observed that exposure of rats to ozone for 12 h per day elicited greater lung changes, which we interpret to indicate a mild fibrotic response, than did exposure of rats for 24 h per day, whether or not there was accompanying exposure to the acid aerosol.

AB - Groups of rats were exposed to either 0.12 or 0.20 ppm of ozone, 20, 100, or 150 ppm of sulfuric acid aerosol (04-0.8 pm diameter), or their mixtures in whole body exposure chambers for up to 90 days. Matched control animals were exposed to filtered air in comparable chambers. The rats were examined biochemically and morphometrically for centriacinar fibrosis or other indicators of pollutant-induced changes in the terminal bronchiole-alveolar duct junction region of the lung at the end of the exposures. By evaluating different markers of lung injury, we had previously demonstrated a synergistic interaction between ozone and sulfuric acid aerosol after acute exposures to these same concentrations of the pollutants. The present experiments were designed to answer the question of whether there was any interaction between ozone and respirable sized aerosols of sulfuric acid, synergistic or antagonistic, after chronic exposures. Exposure of rats to 0.12 or 0.20 ppm of ozone elicited tissue and cellular changes at the bronchiole-alveolar duct junction. Concurrent exposure to sulfuric acid aerosol did pot affect the extent or magnitude of these changes. Intermittent exposure (12 h per day) to ozone, with or without the acid aerosol, elicited a greater response than did continuous exposure (24 h per day). No consistent effects of exposure to sulfuric acid aerosol alone were observed, either morphometrically or biochemically. The biochemical data were consistent with the morphometric analyses, showing trends towards or significantly increased lung 4-hydroxyproline content in the rats exposed to ozone, with or without sulfuric acid aerosol, in the intermittent exposure experiment, but not after continuous exposure. No interactive effects between ozone and sulfuric acid aerosol were observed with any of the biochemical parameters examined. We conclude that ozone and sulfuric acid aerosols do not exhibit synergistic interactions after chronic exposures (90 days) of rats to the concentrations tested in this study, which correspond to concentrations showing synergistic interactions in previously performed acute studies. We also observed that exposure of rats to ozone for 12 h per day elicited greater lung changes, which we interpret to indicate a mild fibrotic response, than did exposure of rats for 24 h per day, whether or not there was accompanying exposure to the acid aerosol.

KW - Acid aerosols

KW - Air pollution

KW - Collagen

KW - Lung

KW - Morphometry

KW - Ozone

UR - http://www.scopus.com/inward/record.url?scp=0031029039&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031029039&partnerID=8YFLogxK

U2 - 10.1016/S0300-483X(96)03535-4

DO - 10.1016/S0300-483X(96)03535-4

M3 - Article

C2 - 9020514

AN - SCOPUS:0031029039

VL - 116

SP - 133

EP - 146

JO - Toxicology

JF - Toxicology

SN - 0300-483X

IS - 1-3

ER -