1. What are Mast Cells ?
Mast cells belong to the family of �white blood cells� most of which are produced in our bone marrow. In contrast to most other bone marrow-derived cells, mast cells are not found in the peripheral blood, but are located in the tissues where they reside for many months or even years.
Like most white blood cells, mast cells belong to the immune system that helps in the body�s defence against bacteria and other microbes. As part of an alarm system, mast cells can respond very rapidly to foreign attacks of microbes by releasing potent vasoactive and defence-related molecules into the tissues in local areas.
These chemical mediators are released from mast cells systemically in our body during a severe allergic reaction which may result in the clinical picture of anaphylaxis.
One of the most important chemical mediators of mast cells is histamine, which can cause tissue swelling (edema), itching, flushing, and redness of our skin, but also headache, nausea, dizziness, or diarrhoea.
Histamine can also augment other gastrointestinal problems or be involved in ulcerative diseases of the gastrointestinal tract (like gastric ulcer). Finally, histamine is a �neuroactive� mediator and can influence the blood pressure.
Apart from histamine, mast cells also produce numerous other chemical substances and cytokines. |
