Thermoregulatory effects following exposure to particulate matter in healthy and cardiopulmonary-compromised rats

Epidemiological studies have correlated human exposure to ambient particula te matter (PM) with increased morbidity and mortality, particularly in card iopulmonary-compromised individuals. We conducted experimental studies usin g radiotelemetry methodology to examine the effects of PM; exposure in heal thy and compromised rats. Examples of ambient, combustion, and natural sour ce particles, along with their primary metallic constituents, were tested i n rodent models chosen to simulate human conditions of systemic hypertensio n, pulmonary hypertension, pulmonary inflammation, and general cardiac stre ss. Results indicate that PM induces a robust hypothermia, along with signi ficant decreases in cardiac function, leading to arrhythmogenesis and letha lity. These results support those of previous epidemiological studies. (C) 2000 Elsevier Science Ltd. All rights reserved.