Degranulation of rat mast cells in vitro by the fungal cytolysins phallolysin, rubescenslysin and fascicularelysin.

Phallolysin from Amanita phalloides (Vaill. ex Fr.) Secr., rubescenslysin from Amanita rubescens (Pers. ex Fr.) Gray, and fascicularelysin from Hypholoma fasciculare (Huds. ex Fr.) Kummer, in vitro caused disruption of mast cells in rat mesentery. The mast-cell-degranulating potency of rubenscenslysin and fascicularelysin roughly corresponded to their haemolytic potency; the dose-response curves were extremely steep and the cells were either completely destroyed or remained intact. The action of rubescenslysin and fascicularelysin was very fast: at 37 degrees C 95 resp. 90% of the cells were disrupted within 5 min. Phallolysin degranulated mast cells only at 10-50-fold haemolytic concentrations; the concentration-response curve was flatter, and the effect less radical: a high percentage of the cells underwent only incomplete degranulation. 75% of the cells were degranulated within 5 min. Fascicularelysin released marker molecules from both, lecithin and sphingomyelin liposomes.