IMMUNOLOGY

Detailed explanation-1: -Mast cells are now thought to exert critical proinflammatory functions, as well as potential immunoregulatory roles, in various immune disorders through the release of mediators such as histamine, leukotrienes, cytokines chemokines, and neutral proteases (chymase and tryptase).

Detailed explanation-2: -Histamine is the most important mediator released from the mast cell involved with an allergic response. Histamine is derived from the amino acid histidine and works through three different receptors (H1, H2, H3). Stimulation of H1 receptors by the binding of histamine induces the classic allergic reaction.

Detailed explanation-3: -Mast cells are key players in the inflammatory response as they can be activated to release a wide variety of inflammatory mediators, by many different antigens including allergens, pathogens and physiological mediators.

Detailed explanation-4: -Mast cells can modulate host innate immune responses through the release of granular and secreted mediators (reviewed in [1], [2]). The release of histamine and other vasoactive mediators increases vascular permeability and local blood flow, and can act on smooth muscle to increase the expulsion of mucosal parasites.