Inflammatory effects of inhaled endotoxin-contaminated metal working fluid aerosols in rats.

Exposure to aerosols generated from water-soluble metal-working fluids (MWF) is associated with numerous respiratory symptoms consistent with an acute pulmonary inflammatory event. Previous studies in mice and guinea pigs have implicated endotoxin contamination of MWF as the causative agent responsible for inducing pulmonary neutrophilia and decrements in airway conductance. However, little information is known about the relationship between endotoxin-contaminated MWF exposure and changes in airway physiology. The present study, utilizing a rat model, has demonstrated that exposure to 10 mg/m 3 with endotoxin (0 to 3.2 w g/m 3 ) resulted in a time- and concentration-dependent migration of neutrophils in the lung tissue's interstitial spaces as well as the lavageable airways. In contrast to other airborne toxicants, where neutrophil infiltration of the lung has been associated with hyperresponsive airways, the endotoxin-induced neutrophilia observed in the present study was not associated with airway hyper...