Rat alveolar macrophage production of chemoattractants for neutrophils: response to Escherichia coli endotoxin.

摘要: Endotoxemia in rats is associated with the accumulation of neutrophils (polymorphonuclear leukocytes) within airspaces lung. Polymorphonuclear leukocyte influx appears to be regulated by intrapulmonary chemotactic activity. Since alveolar macrophages (AMS) are prevalent cells airspace and known release a variety factors, we investigated effect endotoxin exposure on AM production We tested hypothesis that endotoxin-exposed AMs have an augmented ability produce chemoattractants. recovered bronchoalveolar lavage from control treated vivo "low dose" (2.5 mg/kg) or "high (5.0 Escherichia coli endotoxin. These were then cultured vitro for 15 h absence presence (15 30 micrograms/ml) stimulate found stimulated normal secrete chemoattractants dose-dependent fashion. spontaneously secreted more than rats. Exposure followed stimulation resulted even greater AMs. significant association between percent polymorphonuclear leukocytes same specimen. The level activity produced predicted degree Partial purification indicated this has two molecular weight peaks, one near 1,000 other 50,000. was stable at 100 degrees C least min degradable trypsinization. conclude can induce prior affects response exposure. By inference, it possible endotoxin-macrophage interaction may serve as biologic amplifier effects role pathogenesis septic lung injury humans.