Histamine

Histamine is a biogenic amine chemical involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. New evidence also indicates that histamine plays a role in chemotaxis of white blood cells.

Storage and Release

Most tissue histamine is found in granules in mast cells or basophils. Mast cells are especially numerous at sites of potential injury - the nose, mouth, and feet; internal body surfaces; and blood vessels. Non-mast cell histamine is found in several tissues, including the brain, where it functions as a neurotransmitter. Another important site of histamine storage and release is the enterochromaffin-like (ECL)cell of the stomach.

Related Topics:
Mast cells - Basophils - Enterochromaffin-like (ECL)cell

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The most important pathophysiologic mechanism of mast cell and basophil histamine release is immunologic. These cells, if sensitized by IgE antibodies attached to their membranes, degranulate when exposed to the appropriate antigen. Certain amines, including drugs such as morphine and tubocurarine, can displace histamine in granules and cause its release.

Related Topics:
IgE - Antigen - Morphine - Tubocurarine

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