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CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS) DURING FALL SEASON IN WISTAR-KYOTO RATS
Kodavanti, U P., M. Schladweiler, A. D. Ledbetter, L. C. Walsh, P. S. Gilmour, M I. Gilmour, W P. Watkinson, J. P. Nolan, J. H. Richards, D L. Andrews, AND D L. Costa. CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS) DURING FALL SEASON IN WISTAR-KYOTO RATS. Presented at Society of Toxicology 42nd Annual Meeting, Salt Lake City, Utah, March 9-13, 2003.
CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPs) DURING FALL SEASON IN WISTAR-KYOTO RATS.
UP Kodavanti, MC Schladweiler, AD Ledbetter, LC Walsh, PS Gilmour, MI Gilmour, WP Watkinson, JP Nolan, JH Richards, D Andrews, DL Costa. US EPA, ORD, NHEERL, ETD, PTB, Research Triangle Park, NC USA
Animal studies involving CAPs exposures have demonstrated variable pulmonary effects due likely, in part, to the animal model employed and the composition of ambient particulate matter (PM). To determine the consistency of CAPs response with repeated studies, we exposed male Wistar-Kyoto (WKY) and Spontaneously Hypertensive (SH) rats to CAPs in Research Triangle Park, NC (4h/d x 2 consecutive days) and measured pulmonary inflammation, cytokine levels, and changes in plasma fibrinogen and white blood cells. Seven replicates were conducted using the same exposure protocol during the period from August 27-October 24, 2001. The CAPS concentrations ranged from 145-2758 mg/m3, with the highest concentration achieved for the August 27-28 exposure period. After the first week of exposure, the atmospheric temperature dropped significantly; the CAPs concentration also dropped significantly and both parameters remained low for the remainder of the study. There were consistent and significant changes in inflammatory cells in bronchoalveolar lavage fluid (BALF). All seven exposures resulted in significant decreases in total lavageable cells, and increases in neutrophils in WKY rats. The smallest increase was noted during the first week of exposure. The biochemical measures of BALF such as protein, albumin, lactate dehydrogenase and cytokines were variable. A small but consistent plasma fibrinogen increase was apparent only in SH rats at all exposures except the first. Plasma fibrinogen increases were not as consistent in WKY rats despite a significant inflammatory response in all replicates. This study demonstrates the potential variability between animal models and indicates that the season, and likely the composition of the atmospheric PM, may have a greater influence on CAPs-induced health effects than previously reported. (This abstract does not reflect US EPA policy).