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Platelet activating factor does not release histamine from human dispersed cutaneous mast cells
Author(s) -
THOMAS G.,
CHURCH M. K.
Publication year - 1990
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.1990.tb02797.x
Subject(s) - histamine , platelet activating factor , mast cell , histamine h4 receptor , chemistry , calcium , endocrinology , liberation , extracellular , platelet , compound 48/80 , medicine , pharmacology , histamine h2 receptor , immunology , degranulation , biology , biochemistry , receptor , antagonist , in vitro
Summary Histamine H 1 ‐antagonists inhibit the weal‐and‐flare responses to the intradermal injection of platelet activating factor (PAF) in humans, and PAF response is reduced in histamine‐depleted skin sites. This indicates that mast cell histamine release is likely to be the mechanism of this response. We have therefore studied the interaction of PAF with cutaneous mast cells by observing whether it releases histamine directly from human dispersed foreskin mast cells, potentiates the activity of known mast cell stimulants or liberates histamine releasing factors (HRFs) from human platelets and leucocytes to release mast cell histamine by an indirect mechanism. At a concentration of 100 μM both PAF C 18 and PAF C 16 caused near maximal release (83·5±4·3% and 88·2 ± 4·5% respectively) of the total histamine content of the cell. This release was not inhibited in the absence of extracellular Ca 2+ , by the lack of metabolic energy or in the presence of the PAF antagonists WEB 2086 (100 nM‐3μM) or BN 52021 (100 nM–10 μM). These results indicate a cytotoxic mechanism of histamine release by PAF 100 μM. PAF (10nM–1 μM) failed to potentiate the mast cell‐stimulating activity of anti‐IgE, calcium ionophore A23187 or substance P and it did not induce the release of HRFs for skin mast cells when incubated with platelets and leucocytes in concentrations up to 1 μM.