Desensitization to PAF-induced bronchoconstriction and to activation of alveolar macrophages by repeated inhalations of PAF in the guinea pig.
Guinea-pig alveolar macrophages are activated in the presence of PAF-acether (PAF), as shown by O2.- production, suggesting that these cells, abundant in the lungs, are involved in PAF-induced bronchoconstriction. Alveolar macrophages collected after in vivo desensitization to the bronchoconstrictor effect of PAF became refractory to it in vitro, whereas the O2.- production in response to f-met-leu-phe persisted, although it was diminished suggesting a partial cross-desensitization. A similar desensitization to PAF was also observed in alveolar macrophages in vitro, demonstrating a stimulus-specific process. This study suggests that alveolar macrophages may be involved in bronchoconstriction induced by aerosol of PAF.
D000336:Aerosols; D000818:Animals; D001982:Bronchial Diseases / Q000209:etiology*; D003251:Constriction, Pathologic / Q000209:etiology; D004361:Drug Tolerance; D006168:Guinea Pigs; D007700:Kinetics; D008262:Macrophage Activation; D008264:Macrophages / Q000502:physiology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000502:physiology*; D011650:Pulmonary Alveoli / Q000166:cytology*; D013481:Superoxides / Q000378:metabolism
D000336:Aerosols; D010972:Platelet Activating Factor; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine