Antipyretic effect of centrally administered CRF

CRF injected into the third cerebral ventricle (0.5-2.5 micrograms) caused dose-related reductions in fever induced in rabbits by IV administration of leukocytic pyrogen. Control injections of CRF when the same animals were afebrile did not alter normal body temperature. Intravenous injections of 5 and 20 micrograms CRF, doses known to release ACTH and corticosteroids into the bloodstream in other species, did not reduce fever. CRF injected into the cerebral ventricles may be antipyretic per se, or it may reduce fever by virtue of central release of the antipyretic peptides ACTH and alpha-MSH.