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EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS
Citation:
Wichers, L. B., J. P. Nolan, D. W. Winsett, U P. Kodavanti, M. Schladweiler, D L. Costa, AND W P. Watkinson. EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS. Presented at American Thoracic Society, Seattle, WA, May 16-21, 2003.
Description:
EFFECTS OF ACUTE EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON CARDIOPULMONARY, THERMOREGULATORY, AND BIOCHEMICAL PARAMETERS IN HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS. LB Wichers1, JP Nolan2, DW Winsett2, UP Kodavanti2, MCJ Schladweiler2, DL Costa2, and WP Watkinson2 1UNC SPH, Chapel Hill, NC, USA; 2USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, USA.
A consensus of epidemiological studies has shown a direct association between exposure to ambient particulate matter (PM) and morbidity and mortality, with the highest correlations seen in persons with cardiopulmonary disease. Supporting data from animal studies are sparse and generally derived from exposures to high doses of fairly toxic PM surrogates. To investigate this phenomenon using a more environmental PM model, we exposed healthy (SAL) and monocrotaline (MCT)-treated Sprague-Dawley rats to Concentrated Ambient Particulates (CAPs) from Research Triangle Park, NC; paired groups were exposed to filtered air (AIR). Rats (n=16) were implanted with radiotelemeters to monitor electrocardiogram, heart rate (HR), and core temperature (Tco). Animals were divided into four equal groups (SAL/AIR; MCT/AIR; SAL/CAPs; MCT/CAPs) and exposed (4h/d?3d) via nose-only inhalation to CAPs (220?1400 g/m3). Telemetered rats were monitored throughout the experimental time period (5-min intervals) and ventilatory function was examined daily (10-min duration). At 24h postexposure, rats underwent bronchoalveolar lavage (BAL) and the BAL fluid was examined for biochemical indices of pulmonary injury and inflammation. CAPs animals showed increases in HR ( 50 bpm) on Exposure Day 1 and decreases in Tco ( 1 C) on Days 1?2. BAL protein and albumin were elevated in CAPs rats (MCT>SAL). The above effects, while mild compared to those of previous studies that exposed MCT-rats to residual oil fly ash, nevertheless demonstrate a small toxic response in compromised rats following nose-only exposure to CAPs that, when projected over larger subject numbers, may help explain some of the reported epidemiological findings. (Abstract does not represent USEPA policy. This research was supported in part by EPA CT826513.)