The influence of phosphatidyl serine on the release of histamine from isolated rat mast cells induced by different agents.

The influence of phosphatidyl serine (PS) on histamine release from isolated rat mast cells induced by antigen, compound 48/80, adenosine-5'-triphosphate (ATP), the ionophore A23187, and decylamine was studied. PS enhanced antigen-induced release but inhibited the release caused by compound 48/80, A23187, and decylamine. PS did not influence the release induced by ATP. The different effects of PS on the action of the various histamine releasing agents do not conform to a unifying model for the action of PS on the release process. Possible interactions between PS and the agents in the incubation medium as well as at specific reactive sites on the plasma membrane might explain some of the effects of PS. Consequently, the results cannot be used as evidence for the existence of basic differences in the release process induced by various calcium- and energy-dependent releasing agents.