In vitro culture systems using bone marrow cells from BALB/C mice were set up in medium supplemented with spleen-derived medium. Bone marrow cells grown in spleen-derived medium gave rise to cultures containing >97% mast cells. The cells were used in polarisation chemotaxis assays with the intention of determining the effect of nerve tissue-derived neurotransmitters on mast cell migration. ...

Itch can be suppressed by painful stimuli, but the underlying neural basis is unknown. We generated conditional null mice in which vesicular glutamate transporter type 2 (VGLUT2)-dependent synaptic glutamate release from mainly Nav1.8-expressing nociceptors was abolished. These mice showed deficits in pain behaviors, including mechanical pain, heat pain, capsaicin-evoked pain, inflammatory pain...

Histamine is synthesized via histidine decarboxylase (HDC) in wide types of immune cells and is involved in abundant physiologic and pathologic processes. Histamine is a mediator released during inflammatory reactions, such as food allergy. Food allergy is immunological reactions to 'fight off' specific allergens within food in susceptible individuals. The aim of this study is investigation of ...

In this study, the effects of intraperitoneal (ip) injection of physostigmine, subcutaneous (sc) injection of atropine, and intracerebroventricular (icv) injections of histamine, chlorpheniramine (H(1)-receptor antagonist), and ranitidine (H(2)-receptor antagonist) in separate and combined treatments were investigated during yawning in rats. Physostigmine at a dose of 0.25 mg/kg produced the hi...

BACKGROUND Annona vepretorum Mart. (Annonaceae) is a native tree from Caatinga (Brazilian Northeastern savanna biome), popularly known as "araticum" and "pinha da Caatinga". In this study, we investigated the effects of the crude ethanolic extract (Av-EtOH) in models of pain and inflammation in rodents. METHODS The evaluation of antinociceptive activity was carried out by the acetic acid-indu...

Changes in cyclic nucleotide production and atrial dynamics have been known to modulate atrial natriuretic peptide (ANP) release. Although cardiac atrium expresses histamine receptors and contains histamine, the role of histamine in the regulation of ANP release has to be defined. The purpose of the present study was to define the effect of histamine on the regulation of ANP release in perfused...

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...

Glucagon-like peptide-1 (GLP-1), corticotropin-releasing hormone (CRH), and hypothalamic neuronal histamine suppress food intake, a target of leptin action in the brain. This study examined the interactions of GLP-1, CRH, and histamine downstream from the leptin-signaling pathway in regulating feeding behavior. Infusion of GLP-1 into the third cerebral ventricle (i3vt) at a dose of 1 mug signif...

Functional brain imaging studies on itch usually use histamine as a stimulus and, in consequence, have to cope with the highly variable time course of this particular itch sensation. In this study, we describe a novel method of histamine application. To provoke itch, a mixture of histamine and codeine was applied through intradermally positioned microdialysis fiber. The itch was terminated by l...

Dexmedetomidine is a sedative and analgesic agent that exerts its effects by selectively agonizing α2 adrenoceptor. Histamine is a pathophysiological amine that activates G protein-coupled receptors, to induce Ca(2+) release and subsequent mediate or progress inflammation. Dexmedetomidine has been reported to exert inhibitory effect on inflammation both in vitro and in vivo studies. However, it...