MICROINJECTION OF A CYCLOOXYGENASE INHIBITOR INTO THE ANTEROVENTRAL PREOPTIC REGION ATTENUATES LPS FEVER

Considerable evidence supports the role of prostaglandins in fever pro duction, but the neuroanatomic sites of prostaglandin synthesis that p roduce fever remain unknown. With the use of a novel microinjection te chnique, we injected the cyclooxygenase inhibitor ketorolac into the p reoptic area (POA) to determine which preoptic regions produce the pro staglandins required for fever. Initial experiments demonstrated that intravenous ketorolac blocked the fever normally produced by lipopolys accharide (LPS) 5 mu g/kg iv. Microinjection of ketorolac into the POA had no effect on body temperature, and injection of artificial cerebr ospinal fluid into the POA did not alter LPS fever. Injection of ketor olac into the anteroventral POA markedly decreased the fever produced by LPS, compared with injections into more rostral, caudal, or dorsal locations. These observations indicate that prostaglandin synthesis in the anteroventral preoptic region is necessary for the production of fever.