CHRONIC SOCIAL STRESS AND CARDIOVASCULAR RESPONSE TO CONCENTRATED PARTICULATE AIR POLLUTION (CAPS) IN RATS

Background and Aims: Epidemiologic evidence suggests that chronic stress may alter susceptibility to air pollution. Persistent spatial confounding between these exposures, however, limits the utility of epidemiologic methods alone to disentangle these effects, and it can not identify physiologic mechanisms. Methods: Using a rat model of social stress, we examine continuous respiratory and cardiovascular responses to concentrated fine ambient particles (CAPs). Twenty-four 12-week old male Sprague-Dawley rats are randomly assigned to four groups (Stress/CAPs; Stress/Filtered Air (FA); Non-stress/CAPs; Non-stress/FA). Stress group animals are individually introduced into a dominant male’s home cage twice weekly. Blood drawn at sacrifice is analyzed for immune and inflammatory markers. CAPs are generated using the Harvard fine particle concentrator, which enriches real-time urban ambient fine particles by approximately a factor of 30. CAPs/FA exposures are delivered in single-animal plethysmographs, 5 hours/d...