ИСТИНА

Mast cells are known to be among the most important effector immunocompetent cells participating in various biological responses. The description of the mast cell in connective tissue is ascribed to Ehrlich. Ehrlich made the important discovery that the mast cell stained well and specifically with certain dyes of the aniline family, the specific metachromatic staining reaction. Ehrlich also proposed the relation of mast cells with inflammation, blood vessels and neural tissue. Mast cell develop from progenitor cells that in turn arise from uncommited hemopoietic stem cells in the bone marrow, they undergo terminal differentiation in tissues. It was determined that IgE molecules have a high affinity for specific receptors on mast cells and that the reaction of cell-bound IgE molecules with multivalent antigens or divalent anti-IgE antibody induces the release of a variety of chemical mediators from the cells, that testify a central role for the mast cell in immunological reactions. More recently the role of mast cells in inflammatory disease and host defense was established. Following activation, these cells express mediators such as histamine, leukotrienes and prostaglandins, as well as proteases, and many cytokines and chemokines, pivotal to the genesis of an inflammatory response. Mast cells have been shown to play roles in allergic inflammation, and more recently, they have been shown to modulate coagulation cascades, host defense and tissue remodeling. Although mast cells were discovered long ago they are certainly no less interesting today and their history is far from complete