Immunoreactivity for matrix metalloproteinase (MMP)-9 protein in polymorphonuclear leukocytes (PMN) and in alveolar macrophages (AM), respectively, in bronchoalveolar lavage (BAL) samples harvested from vehicle (Veh) - and endotoxin (E)-exposed bronchial segments in healthy subjects.

Footnote. Immunoreactivity assessed using immunocytochemistry of BAL cells on cytospin slides. Samples were harvested 24 (n = 6) and 48 (n = 7) hours (h) after exposure. Data presented as median values (range), in percent of respective cell type. Asterisks indicate statistically significant differences between samples from endotoxin- and vehicle-exposed segments (* = p<0.05, paired test).