Studies on the pathogenesis of fever. VIII. Further observations on the role of endogenous pyrogen in endotoxin fever.

Rabbits made granulocytopenic with nitrogen mustard have been shown to generate serum endogenous pyrogen when given a fever-producing dose of bacterial endotoxin. This finding is in accord with the hypothesis that endogenous pyrogen plays a central role in the pathogenesis of endotoxin fever. The fact that leucopenic animals produce less serum-endogenous pyrogen than normal animals given the same dose of endotoxin has also been confirmed and suggests that polymorphonuclear leucocytes constitute a major source of the endogenous pyrogen which is demonstrable in the circulation during endotoxin fever.