Mast cells play an important role in the body's immune response. They contain several kinds of chemicals. One is heparin, which prevents blood from clotting in the blood vessels. Two others are histamine and serotonin. They act to dilate or widen small blood vessels.
Mast cells play an important role in the body's immune response.
A type of antibody, IgE adheres to the surface of mast cells. When a foreign substance is identified by the IgE, the mast cell releases its chemicals. These chemicals affect the local blood vessels to allow delivery of specific white blood cells which arrive to eliminate the foreign substance. Unfortunately, these chemicals are also responsible for the annoying symptoms of an allergic reaction. Swelling, redness and itching can all be attributed to the contents of the mast cells.