title: [Antipyretic action of dexamethasone on egtazic acid-induced fever in rabbits].
abstract: The purpose of the present study was to investigate whether the antipyretic effect of dexamethasone (DEX) delivered by intravenous injection (i.v.) on intracerebroventricularly (icv) administered egtazic acid-induced febrile response is relevant to the changes in cytosolic free calcium concentration of the hypothalamus. The colon temperatures were measured by a thermistor and the cytosolic free calcium concentration ([Ca2+]i) in dissociated brain cells was measured by Fura 2-AM. The results demonstrated that the pyretic action of egtazic acid (0.6 mumol, icv) was markedly inhibited by DEX (5 mg/kg, i.v.), but DEX (60-120 mumol/L) did't affect [Ca2+]i in dissociated hypothalamus cells. Actinomycin D, which interferes with gene transcription (3 nmol, icv), completely abolished the antipyretic action of DEX on egtazic acid-induced fever. These findings suggest that the antipyretic action of DEX on egtazic acid-induced fever is related to the activation of certain gene expression in the brain, but not to the changes of transmembrane calcium ion current in hypothalamus neurons.
authors.affiliation: Department of Pathophysiology, Medical College of Jinan University, Guangzhou, 510632.
authors.forename: H D
authors.initials: HD
authors.lastname: Wang
authors.forename: Y P
authors.initials: YP
authors.lastname: Wang
authors.forename: C J
authors.initials: CJ
authors.lastname: Li
authors.forename: D X
authors.initials: DX
authors.lastname: Lu
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: R B
authors.initials: RB
authors.lastname: Qi
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D004533:Egtazic Acid; D005260:Female; D005334:Fever / Q000139:chemically induced; D015870:Gene Expression; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D011817:Rabbits
chemical_list: D018712:Analgesics, Non-Narcotic; D004533:Egtazic Acid; D003907:Dexamethasone