Inhibition of mast cell histamine secretion by N-substituteed derivatives of phosphatidylserine.

The structural basis for the highly specific action of phosphatidylserine in enhancing mast cell histamine secretion induced by concanavalin A was investigated by studying the activities of three N-substituted derivatives: N-acetyl phosphatidylserine, N-1-dimethylaminonaphthalene-5-sulfonly phosphatidylserine, and N-4-nitrobenzo-2-oxa-1,3-diazole phosphatidylserine. None of the derivatives was capable of activating concanavalin A-induced histamine secretion at concentrations two to three times that required for maximal activation by phosphatidylserine. Instead, the derivatives were found to inhibit the secretory response of mast cells to the calcium ionophore A23187 as well as to concanavalin A. The inhibition was noncytotoxic, partially reversible by washing, and associated with binding of N-substituted phosphatidylserine to the mast cell.