Alterations in cardiovascular function by particulate matter in rats using a crossover design

Abstract The objective of this study was to investigate associations between cardiovascular effects and urban ambient particle constituents using an in vivo crossover experimental design. Ambient particles were introduced to an exposure chamber for whole-body exposure of WKY rats, where the particulate matter with an aerodynamic diameter of 2.5 ) mass concentration, particle number concentration, and black carbon (BC) were monitored. Organic carbon (OC), elemental carbon (EC), and soluble ions of PM 2.5 were determined. In a crossover design, rats were exposed to ambient particles or high-efficiency particle arrestance (HEPA)-filtered control air for 7 days following a 7-day washout interval. The crossover exposure between particles and HEPA-filtered air was repeated 4 times. Radiotelemetric data on blood pressure (BP) [systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP)], heart rate (HR), and heart rate viability (HRV) were subsequently obtained during the entire study. Exposure to the PM 2.5 mass concentration was associated with decreases in the SBP, DBP, MAP, and HR ( p 2.5 mass concentration ( p + , Cl − , and NO 3 − . Cl − was associated with the DBP, MAP, HR, SDNN, and RMSSD. NO 3 − was correlated with the SBP, MAP, HR, SDNN, and RMSSD. In conclusion, we observed cardiovascular responses to ambient particles in vivo using a crossover design which can reduce animal use in future environmental studies.