Ultrastructural changes in the lung following exposure to perfluoroisobutylene (PFIB) and potentiation of PFIB-induced lung injury by post-exposure exercise

摘要

The authors investigated the kinetics of development of the injurious effects of perfluoroisobutylene (PFIB) in the lower respiratory tract of the rat as a function of inhaled mass concentration. We additionally examined if exercise performed after exposure to PFIB can potentiate the severity of expression of PFIB-induced lung injury, while also assessing how PFIB exposure may result in reductions in work performance capacity. The severity of PFIB-induced lung injury was found to be directly proportional to inhaled PFIB mass concentration whereas the post-exposure kinetics of development of the injurious response was inversely proportional to the mass concentration of PFIB, with post-exposure latency periods prior to the onset of detectable injury increasing with decreasing inhaled mass concentration. Exercise was found to potentiate PFIB-induced lung injury only after pulmonary edema was demonstrably present using lung gravimetric and light histopathologic criteria, even though ultrastructural observations indicated significant cellular changes occur during the latency period. Our collective findings suggest that pre-existing permeability changes in the lung are a necessary prerequisite for post-exposure exercise to exert a potentiating effect. Reductions in work performance capacity occurred only after the latency period, and such reductions proportionately scaled with the severity of pulmonary edema. 9 refs., 5 figs.