In-vitro effects of Clostridium welchii type-D epsilon toxin on guinea-pig, mouse, rabbit and sheep cells.

Epsilon toxin, at relatively low concentrations, killed guinea-pig peritoneal macrophages in vitro. The cells became swollen, the nuclear and cytoplasmic membranes "blistered" and discontinuous, and the cytoplasm appeared structureless. Formalinised epsilon prototoxin was shown to bind closely to the outer surface of the cells and it is concluded that this site represents the location of the receptors for epsilon toxin. In addition the toxin at higher concentrations killed rabbit peritoneal macrophages after increased periods of incubation, but had no demonstrable effect on other cells from guinea-pigs, rabbits, mice and sheep.