title: Generation and metabolism of leukotrienes and release of histamine from human dispersed tonsillar cells.
abstract: We studied the generation and metabolism of leukotrienes (LT) and the release of histamine by human tonsillar cell suspensions. Human tonsils were dissected and mechanically dispersed. This procedure yielded a single cell suspension with 1.6 +/- 0.5 X 10(8) cells/g tissue consisting of 97.3 +/- 0.4% lymphocytes, 1.4 +/- 0.3% granulocytes, 1.3 +/- 0.3% macrophages/monocytes, and 0.03 +/- 0.02% mast cells/basophils. The cells were stimulated either with Ca-ionophore A 23187, melittin, or anti-human IgE. Determination of the 5-lipoxygenase products LTB4 and LTC4 was performed with specific radioimmunoassays (RIA), and histamine release was measured by the fluorophotometric technique. A time- and dose-dependent release of the mediators was monitored. LTB4 exceeded the amount of LTC4 in the supernatants. The concentration of leukotrienes ranged between 0.8 and 5.4 ng LTB4/1 X 10(8) cells or 0.5 and 1.5 ng LTC4/1 X 10(8) cells, depending on the stimulus. Histamine release after stimulation ranged between 25 and 35% of the total histamine content, whereas buffer controls amounted to 17%. The incubation of the cells (1 X 10(8) with exogenously added LTB4 resulted in the formation of omega-oxidated products (20-OH and 20-COOH-LTB4) and a novel unpolar metabolite, as identified by thin layer chromatography. This metabolite was not immunoreactive in the LTB4-RIA used. LTC4 and LTD4 were converted into LTE4 when added either to sonicated cells or to the cell-free supernatants of prestimulated tonsillar cells, indicating the release of gamma-glutamyltranspeptidase and dipeptidase, respectively. Our data clearly demonstrate the generation and metabolism of the 5-lipoxygenase products LTB4 and LTC4 as well as the release of histamine from human dispersed tonsillar cells, suggesting that they have a modulatory function with respect to the inflammatory potential at local sites.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000001:Calcimycin / Q000494:pharmacology; D006636:Histamine Release; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D066298:In Vitro Techniques; D007962:Leukocytes / Q000276:immunology* / Q000378:metabolism; D007975:Leukotriene B4 / Q000096:biosynthesis*; D008555:Melitten / Q000494:pharmacology; D014066:Palatine Tonsil / Q000166:cytology / Q000378:metabolism*; D013189:SRS-A / Q000096:biosynthesis*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D013189:SRS-A; D007975:Leukotriene B4; D008555:Melitten; D007073:Immunoglobulin E; D000001:Calcimycin