Inhalation exposures of rats to aerosolized diesel fuel

The toxicological effects of high concentrations of aerosolized, combusted diesel fuel are being investigated in Sprague-Dawley rats receiving whole-body inhalation exposures. Single exposure for 2 hours to 0.5 to 7 mg/1 resulted in a concentration-related decrease in respiratory frequency during exposure, transiently decreased responsiveness in a startle reflex assay just after exposure, and influx of granulocytes into lungs for several subsequent days. Repeated exposures (a total of 9) with varying aerosol concentration, duration, and frequency have resulted in altered pulmonary free cell number, pulmonary function, responsiveness in startle reflex assay, and histopathology.