Premium
Role of Phospholipase A 2 Activation in Histamine Release from Human Basophils
Author(s) -
Morita Yutaka,
Aida Noriko,
Miyamoto Terumasa
Publication year - 1983
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.1983.tb05084.x
Subject(s) - histamine , histamine n methyltransferase , melittin , histamine h4 receptor , chemistry , basophil , arachidonic acid , liberation , phospholipase a2 , activator (genetics) , phospholipase a , pharmacology , biochemistry , immunoglobulin e , endocrinology , histamine h2 receptor , biology , enzyme , immunology , in vitro , receptor , peptide , antibody , antagonist
The present experiments were undertaken to investigate the role of phospholipase A 2 (PLA 2 ) activation in histamine release from human basophils. A PLA 2 inhibitor, P‐bromophenacyl bromide (BPB), inhibited IgE‐mediated anti‐IgE‐induced histamine release from human basophils with a concentration of drug required to produce 50% inhibition (IC 50 ) of 1.5 × 10 −6 m when leukocytes were preincubated with this agent for 15 min. Histamine release induced by calcium ionophore A23187 and formyl‐l‐methionyl‐l‐leucyl‐l‐phenylalanine was also blocked by BPB with IC 50 of 4.1 × 10 −6 m, and 3.5 × 10 −6 m, respectively. A PLA 2 activator, 12–0‐tetradecanoylphorbol‐13‐acetate (TPA) caused basophil histamine release with a dose‐dependent fashion. BPB inhibited TPA‐induced histamine release (IC 50 : 2.5 × 10 −6 m). However, another PLA 2 activator, melittin, and PLA 2 did not release histamine through non‐cytotoxic mechanisms. Collectively, these results suggest that PLA 2 activation plays a central role in histamine release from human basophils via generation of lysophosphatidylcholine or products of the lipoxygenase pathway of arachidonic acid metabolism.