| Abstract: | Comparative in vivo and in vitro studies were made on bacterial lipopolysaccharide (LPS) and the chemotactic peptide NF-Met-Leu-Phe with a view toward studying their possible role in the pathophysiology of byssinosis. In contrast to LPS, chemotactic peptides did not cause Limulus amebocyte lysate gelation, nor did they induce the release of endogenous pyrogen. Inhalation of LPS caused a peripheral leukocytosis in rabbits 30 min after aerosol administration, whereas peptide inhalation caused a significant leukopenia in the same period. Cellular analysis of guinea pig bronchial lavages after LPS aerosol challenge revealed immediate decreases in all cell types, with subsequent, large increases of macrophages and granulocytes 4-24 h after aerosolization. Inhalation challenge with NF-Met-Leu-Phe induced no significant cellular changes. It was concluded that it is unlikely that these microbial products could be confused with each other when administered in pure form by the inhalation route. |
