title: The effect of haloperidol on the histaminergic neuron system in the rat brain.
abstract: In this study, the effect of haloperidol on histamine (HA) levels, histidine decarboxylase (HDC) activities and the bindings of [3H]-(R)-alpha-methylhistamine ([3H]-(R)-alpha-MeHA) to histamine H3 receptors were investigated in the rat brain. Administration of 10 mg/kg of haloperidol decreased HA levels in the rat striatum and diencephalon, but increased HDC activities in rat striatum and diencephalon, although that of 5 mg/kg did not change them. Meanwhile, haloperidol inhibited the bindings of [3H]-(R)-alpha-MeHA to H3 receptor sites in the rat striatal membrane with a Ki value of 10.5 +/- 0.45 microM. These findings suggest that only a high dose of haloperidol increases HA synthesis and release as a histamine H3 receptor antagonist in the rat brain.
authors.affiliation: Department of Psychiatry, Tohoku University School of Medicine, Sendai, Japan. cito@mail.cc.tohoku.ac.jp
authors.forename: C
authors.initials: C
authors.lastname: Ito
authors.forename: K
authors.initials: K
authors.lastname: Onodera
authors.forename: A
authors.initials: A
authors.lastname: Yamatodani
authors.forename: K
authors.initials: K
authors.lastname: Yanai
authors.forename: E
authors.initials: E
authors.lastname: Sakurai
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D001923:Brain Chemistry / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D006220:Haloperidol / Q000494:pharmacology*; D006632:Histamine / Q000378:metabolism / Q000502:physiology*; D017442:Histamine Agonists / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000378:metabolism; D008761:Methylhistamines / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D017442:Histamine Agonists; D008761:Methylhistamines; C069357:alpha-methylhistamine; D006632:Histamine; D006640:Histidine Decarboxylase; D006220:Haloperidol