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Generation and Metabolism of Leukotrienes and Release of Histamine from Human Dispersed Tonsillar Cells
Author(s) -
SCHLÜTER B.,
SCHÖNFELD W.,
KÖNIG W.
Publication year - 1988
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1988.tb02371.x
Subject(s) - histamine , melittin , metabolite , chemistry , radioimmunoassay , leukotriene , incubation , cell culture , stimulation , ionophore , metabolism , mast cell , biochemistry , endocrinology , microbiology and biotechnology , biology , immunology , membrane , genetics , asthma
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±0.5×10 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 LTB 4 and LTC 4 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 LTB 4 exceeded the amount of LTC 4 in the supernatants. The concentration of leukotrienes ranged between 0.8 and 5.4 ng LTB 4 /1×10 8 cells or 0.5 and 1.5 ng LTC 4 /1×10 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 (1×10 8 ) with exogenously added LTB 4 resulted in the formation of ω‐oxidated products (20‐OH and 20‐COOH‐LTB 4 ) and a novel unpolar metabolite, as identified by thin layer chromatography. This metabolite was not immunoreactive in the LTB 4 ‐RIA used. LTC 4 and LTD 4 were converted into LTE 4 when added either to sonicated cells or to the cell‐free supernatants of prestimulated tonsillar cells, indicating the release of γ‐glutamytranspeptidase and dipeptidase, respectively. Our data clearly demonstrate the generation and metabolism of the 54‐lipoxygenase products LTB 4 and LTC 4 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.