Suppression of anaphylactic shock in sensitized guinea pigs by cytochalasin B.

Twenty-three guinea pigs, presensitized with horse serum, were injected intracardially with 1 ml of 1.5 X 10(-4) M cytochalasin B in a 2.5% dimethyl sulfoxide solution, 1.5 h before being challenged with the serum. Eighteen of the guinea pigs (80%) survived. A single intracardiac injection of cytochalasin B to the control group of guinea pigs at 1.5 h before administration of the allergen did not prevent their sensitization and death following challenge.