Enhanced phospholipid metabolism in rat mast cells stimulated to release histamine.

Incorporation of 32PO4 into the major phospholipids was examined in purified rat peritoneal mast cells stimulated to secrete histamine. Dog anti-rat IgE, concanavalin A, compound 48/80 and the calcium ionophore A23187 all caused significant increases of incorporation of 32PO4 into phosphatidic acid (PA), phosphatidylinositol (PI) and phosphatidylcholine (PC) at concentrations inducing non-cytotoxic release of histamine. The degree of 32PO4 incorporation into these phospholipids paralleled the dose-response curves for histamine release. For anti-IgE and Con A stimulation, histamine release and 32PO4 incorporation into PA, PI and PC were potentiated by passively sensitizing the mast cells with rat IgE or by the addition of phosphatidylserine (PS). These results suggest that enhanced phospholipid metabolism may be an important step in the biochemical sequence of events leading to release of histamine.