Distinctive role of central histamine H3 receptor in various orexigenic pathways

Despite the well-established role of histamine as an anorexigenic neurotransmitter, the role of histamine H-3 receptors in feeding behavior is controversial. Herein we investigated the role of histamine H-3 receptor on several orexigenic agents in mice. Thioperamide (histamine H-3 receptor inverse agonist) inhibited neuropeptide Y- and nociceptin-induced hyperphagia but had no effect on U-50488 (opioid kappa-receptor agonist)-induced hyperphagia. In contrast, imetit (histamine H-3 receptor agonist) inhibited U-50488-induced hyperphagia but augmented neuropeptide Y-induced hyperphagia while it did not alter nociceptin-induced hyperphagia. These results indicate distinctive roles of histamine H-3 receptors in various orexigenic pathways. (c) 2007 Elsevier B.V. All rights reserved.