Mast cell synthesize and/or secrete -
High-Yield Explanation
Type I hypersensitivity reaction is IgE dependent. - cytotoxic IgE antibodies are fixed on the surface of tissue cells ( mast cells and basophils) in sensitized individuals. - the antigen combines with the cell fixed antibody, leading to release of pharmacologically active substance that produces the clinical reaction. - the pharmacological mediators include histamine, serotonin, and chemotactic factors. Histamine is the most impoant vasoactive amine in human anaphylaxis. It is formed by the decarboxylation of histidine found in the granules of mast cells. Reference : Anathanarayan & paniker's 9th edition, pg: 162 <\p>