Tohoku J. Exp. Med., 1997, 183 (4)

The Effect of Haloperidol on the Histaminergic Neuron System in the Rat Brain

CHIHIRO ITO, KENJI ONODERA,1 ATSUSHI YAMATODANI,2 KAZUHIKO YANAI,3 EIKO SAKURAI,3 MITSUMOTO SATO and TAKEHIKO WATANABE3

Department of Psychiatry, Tohoku University School of Medicine, Sendai 980-77, 1Department of Pharmacology, Tohoku University School of Dentistry, Sendai 980-77, 2Department of Medical Physics, School of Allied Health Sciences, Osaka University Faculty of Medicine, Suita 565, and 3Department of Cellular Pharmacology, Tohoku University School of Medicine, Sendai 980-77

  • In this study, the effect of haloperidol on histamine (HA) levels, histidine decarboxylase (HDC) activities and the bindings of [3H]-(R)-a-methylhistamine ([3H]-(R)-a-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)-a-MeHA to H3 receptor sites in the rat striatal membrane with a Ki value of 10.5±0.45 mM. 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.
    Key words--- haloperidol; histamine level; histidine decarboxylase; histamine H3 receptor; rat brain
    © 1997 Tohoku University Medical Press

    Tohoku J. Exp. Med., 1997, 183, 285-292
    Address for reprints: Chihiro Ito, M.D., Department of Psychiatry, Tohoku University School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai 980-77, Japan.
    e-mail: cito@mail.cc.tohoku.ac.jp

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