Suppression of fever in rabbits by a protein synthesis inhibitor, anisomycin

1. The protein synthesis inhibitor, anisomycin, was given into the cerebral ventricles of rabbits as a priming dose followed by a continuous infusion. Doses of 100, 200 and 300 microgram followed by infusions at 100, 200 and 300 microgram/hr inhibited the incorporation of [14C] leucine into hypothalamic protein by over 90%. 2. Injection and infusion of anisomycin (300 microgram) suppressed the febrile response to leucocyte (endogenous) pyrogen given into the ventricles (I.C.V.) or I.V. 3. Dialysis experiments showed that anisomycin did not combine irreversibly with leucocyte pyrogen. 4. Anisomycin did not interfere with thermoregulation in a cold environment. 5. It is concluded that pyrogenesis may involve a step which is dependent on synthesis of hypothalamic protein with a rapid turnover.