title: Inhalation of endotoxin stimulates alveolar macrophage production of platelet-activating factor.
abstract: The production of PAF was studied in alveolar macrophages (AM) and neutrophils recovered by bronchial lavage from guinea pigs exposed to aerosolized bacterial endotoxin (lipopolysaccharide, LPS). The amount of cell-associated PAF was estimated by measuring serotonin release from rabbit platelets. An increased and dose-related production was found in AM for as long as 2 h after a 40-min exposure. No production was detectable after 4 h. Prolonging the exposure did not prolong the response. When a second exposure was given, no PAF could be detected until the time interval between the 2 exposures was 72 h. The amount of neutrophils in lung lavage fluid was elevated about 100 times at 4 h after the exposure, but only a minor PAF production was found in these cells. In view of the role of LPS-contaminated dusts for the development of human lung disease, particularly airway constriction, the role of PAF needs to be further investigated.
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D001792:Blood Platelets / Q000032:analysis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D006168:Guinea Pigs; D007958:Leukocyte Count / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D010972:Platelet Activating Factor / Q000032:analysis / Q000096:biosynthesis*; D011650:Pulmonary Alveoli / Q000166:cytology*; D011817:Rabbits; D012701:Serotonin / Q000097:blood; D013997:Time Factors
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides; D010972:Platelet Activating Factor; D012701:Serotonin