Pseudomonas exotoxin shock. A preliminary report of studies in dogs

A study of shock following infusion of a newly described exotoxin from Pseudomonas aeruginosa (strain P-A-103) in the dog demonstrated two types of reactions: an immediate anaphylactoid reaction from which the dogs usually recovered, and a late hypotensive reaction which persisted and slowly progressed to death in 24 hours in all six of the untreated dogs. The circulatory and certain biochemical changes studied with this exotoxin shock were similar to those observed with endotoxin shock. Pretreatment with saline in five dogs and with nonimmune serum in eight dogs offered no significant protection. Pretreatment with dextran 40 minimized the anaphylactoid reaction but did not provide significant protection against ultimate death. Pretreatment with specific immune serum resulted in survival of all six dogs infused with the exotoxin but did not reduce the severity of transient anaphylactoid reaction.