Mast cell involvement in neurogenic inflammation

Abstract

Mast cells derive from a distinct precursor in the bone marrow [1] and migrate into most tissues, where they acquire distinct characteristics in response to different micro-environmental influences, such as stem cell factor, nerve growth factor, or the cytokines, interleukin (IL)-3, -4 and -6 [2]. Mast cells are responsible for allergic reactions but mounting evidence indicates that they also participate in inflammation [3, 4] and homeostasis [5]. They are present in the meninges [6–11], especially the dura mater, which contains a large proportion of the total intracranial histamine [12]. The mast cells in the dura resemble those in connective tissue since they stain metachromatically with toluidine blue [13] and immunohistochemically for rat mast-cell protease I [14]. Connective-tissue mast cells and mucosal mast cells vary considerably in their staining characteristics as well as in their cytokine content [2, 15]. The mast cells in the rat dura mater, staining violet with toluidine blue, are often seen next to blood vessels (Fig. 1A). This close association with blood vessels can be appreciated better with electron microscopy, showing mast cells “embracing” the endothelial cells that make up the blood vessel wall (Fig. 1B).KeywordsMast CellCluster HeadacheDura MaterNeurogenic InflammationSystemic MastocytosisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.