INHALATION EXPOSURE TO JP-8 JET FUEL ALTERS PULMONARY-FUNCTION AND SUBSTANCE-P LEVELS IN FISCHER-344 RATS

In a simulated military flightline exposure protocol, Fischer 344 rats (F344) were used to investigate the pulmonary effects of JP-8 jet fuel inhalation. Exposures were nose only and for 1 h daily. Groups were exposed for 7 days (7D) or 28 days (28D). Each exposure group had a matched longitudinal control group (LC7 and LC28). Exposure concentrations of 520 mg m(-3) caused an increase in dynamic compliance after 7 days of exposure, but compliance changes were not seen with continued exposure (28D, 495 mg m(-3)). Pulmonary resistance was increased in both 7- and 28-day JP-8-exposed groups. Changes in pulmonary function were accompanied by a decrease in substance P concentrations from the bronchoalveolar lavage fluid (BALF). No significant change was observed in BALF levels of 6-keto-PGF(1 alpha), the stable metabolite of prostacyclin, which is a marker of endothelial cell function. The JP-8-exposed rats gained significantly less weight during the study period than the LC7 and LC28 groups, and the lungs of the 7D group were heavier by wet lung/body weight ratio (Wt(L)/Wt(B)). Alveolar clearance of technetium-labelled diethylenetriamine pentaacetate ([Tc-99m]DTPA) was increased in jet fuel-exposed groups. Light microscopy showed no pathological evidence of lung injury. Recovery from the early pulmonary effects of JP-8 inhalation occurred with continued exposure, as seen by recovery of pulmonary compliance and Wt(L)/Wt(B).