title: Histamine H1 receptors in schizophrenic patients measured by positron emission tomography.
abstract: Increasing evidence has shown that the histaminergic neuron system is implicated in the pathophysiology of schizophrenia. The aim of this study was to compare the distribution of histamine H1 receptors between schizophrenics and normal human subjects in vivo using positron emission tomography (PET). H1 receptor binding was measured in 10 normal subjects and 10 medicated schizophrenic patients by PET and [11C] doxepin, a radioligand for the H1 receptor. The binding potential (BP=Bmax/K(D)) of [11C] doxepin for available brain H1 receptors was calculated by a graphical analysis on voxel-by-voxel basis and compared between schizophrenics and normal subjects using the regions of interest (ROIs) and the statistical parametrical mapping (SPM99). BP values for H1 receptors in the frontal and prefrontal cortices and the cingulate gyrus were significantly lower among the schizophrenic patients than among the control subjects. On the contrary, there were no areas of the brain where H1 receptors were significantly higher among the schizophrenic patients than the control subjects. The results of our study suggest that the central histaminergic neuron system could be involved in the pathophysiology of schizophrenia, although further studies are needed to confirm this hypothesis.
authors.affiliation: Department of Psychiatry, Tohoku University School of Medicine, Sendai 980-8575, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Iwabuchi
authors.forename: Chihiro
authors.initials: C
authors.lastname: Ito
authors.forename: Manabu
authors.initials: M
authors.lastname: Tashiro
authors.forename: Motohisa
authors.initials: M
authors.lastname: Kato
authors.forename: Michiko
authors.initials: M
authors.lastname: Kano
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Itoh
authors.forename: Ren
authors.initials: R
authors.lastname: Iwata
authors.forename: Hiroo
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Mitsumoto
authors.initials: M
authors.lastname: Sato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D004316:Doxepin / Q000378:metabolism; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D011485:Protein Binding / Q000502:physiology; D011969:Receptors, Histamine H1 / Q000378:metabolism*; D012559:Schizophrenia / Q000378:metabolism* / Q000503:physiopathology
chemical_list: D011969:Receptors, Histamine H1; D004316:Doxepin