Histamine release from mast cells

"Histamine release from mast cells" is not a molecule or receptor but rather a biological process. It refers to the exocytosis of preformed histamine and other mediators from cytoplasmic granules within mast cells in response to various stimuli, most notably allergen-induced crosslinking of IgE bound to FcεRI receptors on the mast cell surface[5][6][8]. This rapid degranulation leads to local and systemic effects such as vasodilation, increased vascular permeability, smooth muscle contraction, pruritus (itching), and recruitment of other immune cells[1][4]. The released histamine acts primarily through four G protein-coupled receptors—H1R, H2R, H3R, and H4R—on target tissues[3]. This process is central to immediate hypersensitivity reactions including urticaria (hives), angioedema, anaphylaxis, allergic rhinitis/hay fever, asthma exacerbations triggered by allergens or irritants[6][7]. It also plays roles in innate immunity and tissue repair. Therapeutically relevant drugs do not target "histamine release from mast cells" as a discrete molecular entity but rather modulate it indirectly. For example: - **Mast cell stabilizers** such as ketotifen prevent degranulation and thus block histamine release[1]. - **Antihistamines** block downstream effects at histamine receptors. Biomarkers like serum tryptase are used clinically to confirm episodes of massive mast cell activation such as anaphylaxis or systemic mastocytosis[7]. In summary: "Histamine release from mast cells" describes a key immunologic event/process—not a druggable molecular target—and should not be listed as a canonical therapeutic target. If you are seeking information about specific molecules involved in this pathway for structured data purposes (e.g., FcεRI receptor subunits; enzymes involved in granule exocytosis; the histamine molecule itself), those should be specified individually.

Other names

Mast cell degranulationMast cell histamine secretionMast cell mediator release

Mast cell stabilizers such as ketotifen prevent degranulation and thus block histamine release. Antihistamines block downstream effects at histamine receptors.