title: Therapeutic potential of histamine H3 receptor agonist for the treatment of obesity and diabetes mellitus.
abstract: Histamine H3 receptors (H3Rs) are located on the presynaptic membranes and cell soma of histamine neurons, where they negatively regulate the synthesis and release of histamine. In addition, H3Rs are also located on nonhistaminergic neurons, acting as heteroreceptors to regulate the releases of other amines such as dopamine, serotonin, and norepinephrine. The present study investigated the effects of H3R ligands on appetite and body-weight regulation by using WT and H3R-deficient mice (H3RKO), because brain histamine plays a pivotal role in energy homeostasis. The results showed that thioperamide, an H3R inverse agonist, increases, whereas imetit, an H3R agonist, decreases appetite and body weight in diet-induced obese (DiO) WT mice. Moreover, in DiO WT mice, but not in DiO H3RKO mice, imetit reduced fat mass, plasma concentrations of leptin and insulin, and hepatic triglyceride content. The anorexigenic effects of imetit were associated with a reduction in histamine release, but a comparable reduction in histamine release with alpha-fluoromethylhistidine, an inhibitor of histamine synthesis, increased appetite. Moreover, the anorexigenic effects of imetit were independent of the melanocortin system, because imetit comparably reduced appetite in melanocortin 3 and 4 receptor-deficient mice. The results provide roles of H3Rs in energy homeostasis and suggest a therapeutic potential for H3R agonists in the treatment of obesity and diabetes mellitus.
authors.affiliation: Tsukuba Research Institute, Banyu Pharmaceutical Company, Ltd., Tsukuba, Ibaraki 300-2611, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Yoshimoto
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Ken
authors.initials: K
authors.lastname: Shimamura
authors.forename: Akane
authors.initials: A
authors.lastname: Ishihara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takahashi
authors.forename: Hidehito
authors.initials: H
authors.lastname: Kotani
authors.forename: Airu S
authors.initials: AS
authors.lastname: Chen
authors.forename: Howard Y
authors.initials: HY
authors.lastname: Chen
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Macneil
authors.forename: Akio
authors.initials: A
authors.lastname: Kanatani
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tokita
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects*; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000378:metabolism*; D017442:Histamine Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D007093:Imidazoles / Q000627:therapeutic use*; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D051379:Mice; D018345:Mice, Knockout; D009765:Obesity / Q000188:drug therapy / Q000378:metabolism*; D010880:Piperidines / Q000494:pharmacology; D018100:Receptors, Histamine H3 / Q000187:drug effects / Q000235:genetics; D013890:Thiourea / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D017442:Histamine Agonists; D007093:Imidazoles; D007328:Insulin; D020738:Leptin; D010880:Piperidines; D018100:Receptors, Histamine H3; C077430:imetit; D013890:Thiourea; C052075:thioperamide