To examine the possibility that mast cells have a central role in the pathogenesis of hypersensitivity pneumonitis, 20 patients with this disease were studied with the aim of seeking evidence for mast cell degranulation.The number of mast cells recovered by bronchoalveolar lavage from patients with hypersensitivity pneumonitis was more than 1000 times greater than those recovered from normal in...

The mast cell-mediated allergic reactions are involved in many allergic diseases, such as asthma, allergic rhinitis and sinusitis. Stimulation of mast cells initiates the process of degranulation, resulting in the release of mediators such as histamine and an array of inflammatory cytokines. In this report, we investigated the effect of gossypin (a biflavonoid) and suramin (a synthetic polysulp...

Twelve alcoholic extracts and 12 hexane extracts of plant materials selected on the basis of medicinal folklore for asthma treatment in Indonesia were studied for their activity in inhibiting histamine release from RBL-2H3 cells (rat basophilic leukemia cell line), a tumor analog of mast cells. The results of screening indicated that five alcoholic extracts (Plantago major leaves, Eucalyptus gl...

ETHNOPHARMACOLOGICAL RELEVANCE Gardenia jasminoides Ellis has been used in traditional medicine for treatment of inflammation, edema, and dermaitis. The aim of this study was to investigate the mechanism by which Gardenia jasminoides extract (GJE) elicits anti-allergic effects in mast cells and in mice with atopic dermatitis (AD). MATERIALS AND METHODS We investigated the effects of GJE and i...

We studied the interaction of human neutrophils with nylon wool in vitro and during filtration Ieukapheresis (FL) to better understand cellular events detrimental to neutrophils that occur during FL. When neutrophils purified from blood by gradient centrifugation and sedimentation were incubated with nylon wool in vitro, release of lysozyme from the cells occurred rapidly and to a degree that w...

Histamine is involved in a variety of physiologic responses, such as inflammation, type I allergy, gastric acid secretion, and neurotransmission. Previous studies have focused on specific receptors for histamine and histamine release through degranulation, and the regulation of histamine synthesis and its physiologic roles remain to be clarified. We have studied histidine decarboxylase (HDC), t...

Curcumin, the active component of turmeric, is a polyphenolic phytochemical with anti-tumor, antiinflammatory, anti-oxidative and anti-allergic properties. Mast cells participate in allergic inflammation by virtue of their ability of being activated to allergens and lead to the release of number of biologically active mediators including histamine, prostaglandins, leukotrienes, various cytokine...

Histamine This is concentrated in granular depots within both mast cells and circulating basophils. The Type I mast cells found close to the arterioles and venules seem more important in this regard than the larger, regularly shaped, Type II cells scattered in the perivascular supporting tissues (Beaven, 1976a). Histamine release is accompanied by degranulation of the mast cells and basophils a...

MCS/AHs do not cause rebound congestion with prolonged use (> 3 days), unlike first-line antihistamine/decongestion products. Ophthalmic MCS/AHs block histamine-1 receptors and inhibit the release of histamine from mast cells. Histamine receptor blockage occurs instantly, but preventing mast cell degranulation may take up to 2-4 weeks. This dual approach decreases the signs and symptoms of AC, ...

Upon activation mast cells (MCs) secrete numerous inflammatory compounds stored in their cytoplasmic secretory granules by a process called anaphylactic degranulation, which is responsible for type I hypersensitivity responses. Prestored mediators include histamine and MC proteases but also some cytokines and growth factors making them available within minutes for a maximal biological effect. D...