title: Halothane attenuated haloperidol and enhanced clozapine-induced dopamine release in the rat striatum.
abstract: The effect of halothane anesthesia on changes in the extracellular concentrations of dopamine (DA) and its metabolites (3-methoxytyramine (3-MT), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA)) induced by neuroleptics was studied using in vivo microdialysis techniques. Halothane attenuated haloperidol-induced dopamine release and enhanced clozapine-induced dopamine release in the rat striatum.A microdialysis probe was implanted into the right striatum of male SD rats. Rats were given saline or the same volume of 200 microg kg(-1) haloperidol (D(2) receptor antagonist), 10 mg kg(-1) sulpiride (D(2) and D(3) antagonist), or 10 mg kg(-1) clozapine (D(4) and 5-HT(2) antagonist) intraperitoneally with or without 1-h halothane anesthesia (0.5 or 1.5%). Halothane anesthesia did not change the extracellular concentration of DA, but increased the metabolite concentrations in a dose-dependent manner. The increased DA concentration induced by haloperidol was significantly attenuated by halothane anesthesia, whereas the metabolite concentrations were unaffected. Halothane had no effect on the changes in the concentrations of DA or its metabolites induced by sulpiride. The clozapine-induced increases in DA and its metabolites were enhanced by halothane anesthesia. Our results suggest that halothane anesthesia modifies the DA release modulated by antipsychotic drugs in different ways, depending on the effects of dopaminergic or serotonergic pathways.
authors.affiliation: Medical Clinic of Kumagaya Base, Japan Air Self Defense Force, 839 Jurokuken, Kumagaya City, 360-0846, Saitama, Japan. grd1117@gr.ndmc.ac.jp
authors.forename: Yushi U
authors.initials: YU
authors.lastname: Adachi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Aramaki
authors.forename: Maiko
authors.initials: M
authors.lastname: Satomoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Higuchi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D003024:Clozapine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000378:metabolism*; D006220:Haloperidol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006221:Halothane / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D014150:Antipsychotic Agents; D015102:3,4-Dihydroxyphenylacetic Acid; D003024:Clozapine; D006220:Haloperidol; C001746:3-methoxytyramine; D006221:Halothane; D004298:Dopamine; D006719:Homovanillic Acid