You are here:
EFFECTS OF EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON INDICES OF CARDIOPULMONARY AND THERMOREGULATORY FUNCTION IN HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS
Citation:
Wichers, L. B., J. P. Nolan, U P. Kodavanti, M. Schladweiler, D. W. Winsett, D L. Costa, AND W P. Watkinson. EFFECTS OF EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON INDICES OF CARDIOPULMONARY AND THERMOREGULATORY FUNCTION IN HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS. Presented at Society of Toxicology 42nd Annual Meeting, Salt Lake City, Utah, March 9-13,2003.
Description:
EFFECTS OF EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON INDICES OF CARDIOPULMONARY AND THERMOREGULATORY FUNCTION IN HEALTHY AND MONOCROTALINE-TREATED SPRAGUE-DAWLEY RATS. LB Wichers1, JP Nolan2, UP Kodavanti2, MCJ Schladweiler2, DW Winsett2, DL Costa2, and WP Watkinson2. 1UNC SPH, Chapel Hill, NC, USA; 2USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, USA.
Numerous epidemiological studies have reported a positive association between levels of ambient particulate matter (PM) and morbidity and mortality, noting higher correlations in persons with cardiopulmonary disease. Supporting data from animal studies are sparse and generally derived from exposures to large doses/concentrations of highly toxic PM surrogates. To investigate this phenomenon using a more environmental PM, we exposed healthy (SAL) and monocrotaline (MCT)-treated Sprague-Dawley rats to Concentrated Ambient Particulates (CAPs); paired groups were exposed to filtered air (AIR). Rats were implanted with radiotelemeters to monitor electrocardiogram (ECG), heart rate (HR), and core temperature (Tco). Animals were divided into four groups (SAL/AIR; MCT/AIR; SAL/CAPs; MCT/CAPs) and exposed (4h/d?3d) to RTP CAPs. Telemetered rats were monitored continuously (4d preexposure?1d postexposure) and ventilatory function was examined daily (10 min; 1d preexposure?1d postexposure). At 24h postexposure, rats underwent bronchoalveolar lavage (BAL) to quantify biochemical indices of pulmonary damage and inflammation. On exposure Day 1, increases in HR ( 50 bpm) and decreases in Tco ( 1.0 C) were observed in all CAPs animals. Similar decreases in Tco occurred on Day 2. These effects do not appear to be associated with concentration per se but may be related to differences in PM composition. Protein and albumin in BAL fluid were elevated for rats receiving CAPs and appear exacerbated in MCT-pretreated animals. The above effects, while mild compared to those of previous studies that exposed MCT-SD to Residual Oil Fly Ash PM, nevertheless demonstrate a small toxic response in compromised rats following 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.)