Opioid receptors in the central nervous system are important modulators of itch transmission. In this study, we examined the effect of mixed-action opioid butorphanol on histamine itch, cowhage itch, and heat pain in healthy volunteers. Using functional MRI, we investigated significant changes in cerebral perfusion to identify the critical brain centers mediating the antipruritic effect of buto...

Ménière's disease and related disease of the vestibular system are common and debilitating. Current therapy is multi-modal and includes drug therapy and lifestyle adaptations. Unfortunately many of the drugs used in treatment (particularly those used to control nausea) are sedative and hamper the process of vestibular compensation. Although betahistine (Serc®), BetaSerc®); Solvay Pharmaceutical...

The gastric enterochromaffin-like cell (ECL) has been studied in gastric fundic glands by confocal microscopy and as a purified cell preparation by video imaging of calcium signaling and measurements of histamine release. Regulation of gastric acid secretion is largely due to alterations of histamine activation of the H2 receptor on the parietal cell and can be divided into central neural regul...

Information processing in the striatum is critical for basal ganglia function and strongly influenced by neuromodulators (e.g., dopamine). The striatum also receives modulatory afferents from the histaminergic neurons in the hypothalamus which exhibit a distinct diurnal rhythm with high activity during wakefulness, and little or no activity during sleep. In view of the fact that the striatum al...

Histamine influences many cell types involved in the regulation of innate and adaptive immune responses including antigen-presenting cells (APCs), Natural Killer (NK) cells, epithelial cells, T lymphocytes and B lymphocytes. These cells express histamine receptors (HRs) and also secrete histamine, which can selectively recruit the major effector cells into tissue sites and affect their maturati...

Histamine is a well-known mediator eliciting a broad range of responses in different cell types. Four different subtypes of G protein-coupled histamine receptors (H1-H4) have been cloned and pharmacologically characterized. However, involvement of the different histamine receptor subtypes in immunomodulatory functions of bronchial epithelium has only been investigated marginally. The expression...

PURPOSE Previously, retinopetal axons containing histamine and dopaminergic neurons expressing histamine H(1)-receptor had been localized in mouse retinas using anatomic techniques. The goal of these experiments was to demonstrate that these receptors are functional. METHODS Dopaminergic cells were acutely isolated from retinas of transgenic mice expressing red fluorescent protein under contr...

Mast cells and immature dendritic cells (DC) are in close contact in peripheral tissues. Upon activation, mast cells release histamine, a mediator involved in the immediate hypersensitivity reaction. We therefore tested whether histamine could affect human DC activation and maturation. Histamine induces CD86 expression on immature DC in a dose-dependent (significant at 10(-7) M) and transient m...