OBSERVATIONS ON THE PYROGENIC RESPONSE AND ITS APPLICATION TO THE BIOASSAY OF ENDOTOXIN

Abstract

The febrile response of the rabbit has been studied with respect to its use as an assay for endotoxin. Dose-response relationships have been established for a single endotoxin. The mean pyrogenic response of four or more animals, as measured by the fever index, was shown to be highly consistent and to afford a wide range of dose-related measurements. A standard method for comparing the pyrogenic potency of endotoxin preparations is suggested. Man, cat, horse and the rabbit were found to have the same approximate threshold to pyrogenic stimulation by endotoxin. However, larger doses may be more pyrogenic and more toxic for man than for the rabbit. Both dog and chimpanzee were notably less susceptible to the pyrogenicity of endotoxin than the other species studied.