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CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST
Citation:
GORDON, C. J., M. SCHLADWEILER, Q. T. KRANTZ, C. KING, AND U. P. KODAVANTI. CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST. INHALATION TOXICOLOGY. Informa Healthcare USA, New York, NY, 24(5):296-309, (2012).
Impact/Purpose:
Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood.
Description:
Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood. We exposed WKY rats with or without implanted radiotransmitters to air or DE that was either filtered (F) or unfiltered (DE) containing ~1.9 mg/m3 of PM for 5 hr/d; 5 d/wk; for 4 consecutive wks. Blood pressure (BP), core temperature (Tc), heart rate (HR), and cardiac contractility (CC) were monitored by radiotelemetry during exposure as well as during a 2-wk period of recovery. Pulmonary injury and inflammation markers were analyzed after termination of exposure. Exposure to F or DE was associated with a trend for a reduction in BP during wks 1, 2 and 4. A reduction in HR in the DE group was apparent during wk 4. Exposure to DE but not F was associated with significant reduction in CC over wks 1-4. There was also a slight elevation in Tc during several wks of DE exposure. All telemetry parameters were normal during recovery at night. Neutrophilic inflammation in bronchoalveolar lavage fluid was evident after 2-day and 4-wks of exposure to F and DE; however, there were no signs of inflammation after 2 wks recovery. We found a significant decrease in CC and slight reduction in BP that was independent of Ta. Exposure to DE and F is associated with pulmonary inflammation, and mild effects on HR, BP, and Tc but there is a marked effect of DE on CC.
