Modulation of ozone toxicity with changes in ambient temperature in the unanesthetized, unrestrained rat

Conference · Fri Mar 15 00:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5172702

Watkinson, W P; Wiester, M J ^[1]

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1. Environmental Protection Agency, Research Triangle Park, NC (United States)

Previous studies from this laboratory have demonstrated an attenuating effect of moderate decreases in body core temperature (T{sub co}) on the toxic response to xenobiotic agents. This study examined an additional modulating effect induced by changes in ambient temperature (T{sub a}). Male Fischer 344 rats were implanted with radiometry transmitters that permitted continuous monitoring of T{sub co}, activity, and electrocardiogram (ECG); heart rate (HR) was derived from the ECG signal. Animals were divided into nine treatment groups and continuously exposed to one of three concentrations of O{sub 3} for 48 hrs while maintained at one of three T{sub a}'s. O{sub 3} exposure led to hypothermia and bradycardia at all three T{sub a}'s. Decreases in T{sub co} and HR ranged from 1.5C and 75 bpm in the high T{sub a} group to 6.1C and 250 bpm in the low T{sub a} group. The only lethalities occurred in the high O{sub 3}-low T{sub a} group. Following O{sub 3} exposure, rats were anesthetized with urethane, intubated, and their lungs were lavaged with warm saline. The number of cells/ml in lavage fluid increased proportionally with decreases in T{sub a} and increases in O{sub 3} concentration. Cellular debris and the ratio of white cells/alveolar macrophages increased with increases in O{sub 3}. These results demonstrate the profound impact of T{sub a} on T{sub co} and the subsequent toxic response in the conscious, unrestrained rat exposed to O{sub 3}.

• OSTI ID: 5172702
• Report Number(s): CONF-9104107-; CODEN: FAJOE
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 5:5; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

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LUNGS
SENSITIVITY
OZONE
TOXICITY
AMBIENT TEMPERATURE
ELECTROCARDIOGRAMS
LAVAGE
MACROPHAGES
RATS
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ANIMAL CELLS
ANIMALS
BODY
CONNECTIVE TISSUE CELLS
DIAGRAMS
MAMMALS
ORGANS
PHAGOCYTES
RESPIRATORY SYSTEM
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560300* - Chemicals Metabolism & Toxicology