Activation of histamine secretion from rat mast cells by phosphatidylserine analogues resistant to phospholipase A action.

In order to elucidate how phosphatidylserine enhances histamine release induced by concanavalin A from rat mast cells, two phosphatidylserine analogues were synthesized and their effects were examined. A dialkyl analogue of phosphatidylserine, both ester bonds of which are replaced by ether bonds, potentiated histamine secretion from mast cells stimulated by concanavalin A, although it was much less active than natural phosphatidylserine. An alkyl analogue of phosphatidylserine, in which an ether bond is present at the 1 position, showed almost the same low activity as the dialkyl analogue. It is suggested that deacylation of the incorporated phosphatidylserine by phospholipase A is not required for potentiation by phosphatidylserine and the existence of an ester bond at position 1 is important for phosphatidylserine to enhance concanavalin A-induced histamine secretion from mast cells.