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Ca 2+ influx, phosphoinositide hydrolysis, and histamine release induced by lysophosphatidylserine in mast cells
Author(s) -
Lloret Sergio,
Moreno Juan Jose
Publication year - 1995
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041650112
Subject(s) - histamine , degranulation , intracellular , mast cell , phospholipase , calcium , pertussis toxin , phospholipase c , chemistry , calcium in biology , phospholipase a2 , biochemistry , phospholipase a , inositol trisphosphate , inositol , biology , enzyme , g protein , endocrinology , receptor , immunology , organic chemistry
We have previously demonstrated that snake venom phospholipases A 2 (PLA 2 s) and mammalian PLA 2 s induced inflammatory processes. This effect was correlated with the activity of the enzymes and the release of lipid mediators. We have now determined the role of lysophosphatidylserine (LysoPS) as an inflammatory lipid mediator. Thus, we have studied the possibility that intracellular calcium concentration, phosphoinositide hydrolysis, and the subsequent histamine release in mast cells is due to the action of lysophosphatidylserine. Lysophosphatidylserine‐stimulated release of histamine was significantly higher than release by other lysophospholipids. The contribution of increased phospholipase C activity and the intracellular Ca 2+ influx were therefore examined. LysoPS increased mast cell calcium concentration, and this increment was associated with phospholipase C activation and release of inositol phosphates. The increase in intracellular calucium and histamine degranulation induced by LysoPS were inhibited by apomorphine. Pretreatment of mast cells with pertussis toxin decreased the secretagogic effect of LysoPS and compound 48/80 without modifying the effect of the ionophore A23187. These results suggest that pertussis toxinsensitive G‐protein might be involved in the mast cell degranulation produced by lysophosphatidylserine and allow the increase in phospholipase C activity, thus enhancing intracellular calcium concentration, which then induces exocytosis of histamine. © 1995 Wiley‐Liss Inc.