It is the purpose of this project to study the biological effects of substances from Bordetella pertussis with special emphasis on those substances which induce physiological and immunological responses in experimental animals. Areas of current investigation are: 1) the induction of hyperacute experimental allergic encephalomyelitis by pertussigen and its effect on vascular permeability in the rat's central nervous system utilizing radiolabeled human serum albumin, and 2) characterizing the differences between histamine hypersensitivities produced in mice by endotoxin and pertussigen.