Endotoxin inhalation induces neutrophil chemotaxis by alveolar macrophages.
Guinea-pigs were exposed to an aerosol of bacterial endotoxin (lipopolysaccharide, LPS). The free lung cell response and alveolar macrophage (AM) chemotaxis were studied. Neutrophils from guinea-pig blood gave larger migration responses than those obtained by intraperitoneal glycogen stimulation or human neutrophils. An increase in the number of neutrophils in the airways was found with a peak at 12-24 hours after exposure. In animals pre-treated with LPS inhalation for 4 months, the reaction was of shorter duration and smaller magnitude. AM showed in vitro chemotactic activity up to 4 hours after exposure; no difference was found in pre-treated animals. The results suggest that the neutrophil invasion in the airways after LPS is dependent on two mechanisms, the initial being AM chemotaxis, which is not modified by pre-exposure to LPS, and another unknown factor, which is modified by pre-exposure to LPS.
D000336:Aerosols; D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004731:Endotoxins / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008264:Macrophages / Q000187:drug effects*; D008297:Male; D009504:Neutrophils / Q000187:drug effects*; D011650:Pulmonary Alveoli / Q000473:pathology*; D013997:Time Factors; D015054:Zymosan / Q000494:pharmacology
D000336:Aerosols; D004731:Endotoxins; D015054:Zymosan