mast cell
Last reviewed 01/2018
The mast cell is a fixed connective tissue cell that resembles the circulating blood basophil. The cytoplasm is almost entirely filled with large granules which take up basic dyes.
The granules contain a number of active substances:
- histamine: increases vasodilatation and capillary permeability
- heparin: anticoagulant
- tryptase: activates complement
- platelet activating factor: stimulates platelet degranulation
- eosinophil / neutrophil chemotactic factors: stimulate chemotaxis of both cell types
In addition, mast cells can sythesize arachidonic acid derivatives. They are involved in atopy, type I hypersensitivity and anaphylaxis.