ANTIBODIES TO MACROPHAGE INFLAMMATORY PROTEIN-1-BETA IN PREOPTIC AREAOF RATS FAIL TO SUPPRESS PGE(2) HYPERTHERMIA

This study determined whether macrophage inflammatory protein-1 beta ( MIP-1 beta) plays a role in the hyperthermia caused by prostaglandin E (2) (PGE(2)) given intracerebroventricularly (i.c.v.) in the rat. In t hese experiments, anti-murine MIP-1 beta antibody (anti-MLP-1 beta) wa s micro-injected in the anterior hypothalamic, preoptic area (AH/POA) just before i.c.v. PGE(2). The results showed that anti-MIP-1 beta fai led to alter the PGE(2) hyperthermia. However, immunocytochemical stud ies revealed MIP-1 beta immunoreactivity detectable in both the organu m vasculosum laminae terminalis (OVLT) and AH/POA in the febrile rat. These data thus demonstrate that MIP-1 beta is sequestered in dienceph alic structures underlying thermoregulation even though it is not invo lved in PGE, hyperthermia. This dissociation supports the viewpoint th at at least two distinct systems exist in the brain which underlie a f ebrile response: M-1 beta underlies one component whereas PGE(2) compr ises the other.