a connective tissue cell that contains coarse, basophilic, metachromatic secretory granules that contain, among other pharmacologic agents, heparin, histamine, and eosinophilic chemotactic factor. These cells are involved in immediate hypersensitivity reactions and play a role in the regulation of the composition of ground substance.
[G. Mastszellen, well-fed c. (Ehrlich)]
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Examples: glitazone, GI cocktail, etc.