mast cell n.
A cell found in connective tissue that contains numerous basophilic granules and releases substances such as heparin and histamine in response to injury or inflammation of bodily tissues. Also called labrocyte, mastocyte.
A granular cell found in body tissue, especially connective tissue, that activates inflammation by releasing a variety of chemical substances including histamine, tumor necrosis factor, and interleukins. Mast cells have membrane receptors that bind to bacteria, triggering the release of inflammatory mediators from the mast cell's cytoplasmic granules. Mast cells also play an important role in allergic reactions. Other receptors on their membranes bind to specific antibodies that, combined with certain antigens, initiate granular release of chemical mediators that cause allergic signs and symptoms.