title: Formation of slow-reacting substance of anaphylaxis in human lung tissue and cells before release.
abstract: The capacity to extract slow-reacting substance of anaphylaxis (SRS-A) from human lung tissue or cells after immunologic activation, together with the measurement of SRS-A in both the extract and the surrounding fluid, permits study of total SRS-A generation. That the material extracted is SRS-A was established by both differential bioassay and purification. SRS-A accumulation was entirely intracellular after limited IgE-dependent direct or reversed anaphylactic activation. Intracellular accumulation also generally preceded release, with generation of SRS-A continuing well beyond a plateau in the cellular SRS-A level and the release of preformed mediators. The quantity of SRS-A generated after immunologic activation was modulated by the introduction of exogenous cyclic nucleotides, revealing a site of cyclic nucleotide action distinct from that on mediator release. The capacity to determine not only the release of preformed mediators but also the generation of a newly formed mediator, the sum of SRS-A in cells and supernate, adds an additional dimension to the analysis of the cellular events of immediate hypersensitivity.
mesh_terms: D000707:Anaphylaxis / Q000276:immunology; D000818:Animals; D000941:Antigens; D001681:Biological Assay; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E; D007074:Immunoglobulin G; D008168:Lung / Q000276:immunology*; D051381:Rats; D013189:SRS-A / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D014020:Tissue Extracts
chemical_list: D000941:Antigens; D007074:Immunoglobulin G; D013189:SRS-A; D014020:Tissue Extracts; D007073:Immunoglobulin E; D003994:Bucladesine; D000242:Cyclic AMP; D006152:Cyclic GMP