Demonstration of Endogenous Pyrogen in Serum during Systemic Tuberculin Reaction in Rabbits

SUBSTANCES capable of producing fever in normal recipients (the so-called endogenous pyrogens) appear in the serum of experimental animals during fever due to bacterial endotoxin, influenza virus and streptococcal and pneumococcal infections 1 . Systemic tuberculin reaction is very similar to the effect of bacterial endotoxins 2 . An attempt has therefore been made to demonstrate the presence of substances with an effect corresponding to that of endogenous pyrogen in the serum of experimental rabbits during systemic tuberculin reaction.