title: Complement-induced histamine release from human basophils. I. Generation of activity in human serum.
abstract: The incubation of zymosan, endotoxin, or immune aggregates with normal human serum activates a factor which induces release of histamine from autologous basophils. The reaction can be divided into two steps: in the first, complement must be activated and in the second, the histamine-releasing factor interacts with basophils. The generation of histamine-releasing activity in serum occurs at 17 to 37 degrees C but not at 0 degrees C, is inhibited by heating the serum at 56 degrees C for 30 min, or by the addition of EDTA to the serum. Once generated, the histamine-liberating activity is stable to heating at 56 degrees C for 30 min. Gel filtration of the activated serum demonstrated that this factor eluted in the same region as a factor with chemotactic activity. Both factors have a molecular weight of about 16,000 daltons and their activities were inhibited by antibody to human C5. This is therefore a pathway for histamine release by C5a where the activation of the basophil is unrelated to the membrane bound IgE.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D001491:Basophils / Q000276:immunology*; D002633:Chemotaxis; D002850:Chromatography, Gel; D003165:Complement System Proteins; D004140:Dinitrophenols / Q000276:immunology; D004731:Endotoxins; D005293:Ferritins; D006632:Histamine / Q000032:analysis; D006636:Histamine Release; D006736:Horses / Q000276:immunology; D006801:Humans; D007962:Leukocytes / Q000276:immunology; D010047:Ovalbumin; D012486:Salmonella typhimurium / Q000276:immunology; D013696:Temperature; D013997:Time Factors; D015054:Zymosan
chemical_list: D000936:Antigen-Antibody Complex; D004140:Dinitrophenols; D004731:Endotoxins; D006632:Histamine; D010047:Ovalbumin; D003165:Complement System Proteins; D005293:Ferritins; D015054:Zymosan