title: Neuronal histamine inhibits methamphetamine-induced locomotor hyperactivity in mice.
abstract: Whether central histaminergic (HAergic) neurons mediate the regulation of methamphetamine (MAMP)-induced hyperactivity was clarified. L-histidine (HIS; 500 and 1000 mg/kg i.p.) reduced the locomotor hyperactivity induced by MAMP (1 mg/kg i.p.) in mice, and the effect was significant only at 1000 mg/kg. HIS significantly elevated brain histamine (HA) levels, in both doses, whereas telemethylhistamine (t-MH) levels were elevated only at 1000 mg/kg. Pretreatment with alpha-fluoromethylhistidine, a histidine decarboxylase inhibitor, suppressed both behavioral and biochemical effects of HIS. Metoprine, a HA-N-methyltransferase inhibitor, increased brain HA levels, decreased t-MH levels and suppressed the MAMP-induced locomotor hyperactivity. It is concluded that central HAergic systems may play an inhibitory role on the MAMP-induced locomotor hyperactivity.
mesh_terms: D000818:Animals; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D006948:Hyperkinesis / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*
chemical_list: D008694:Methamphetamine; D006632:Histamine