Mast Cell Study Resources

‭Mast cell‬ ‭ These are the tissue corollary of the polynuclear basophil. It intervenes in hypersensitivity‬ ✪ ‭immediately like the basophil.‬ ‭ Morphology:After MGG, it is characterized by metachromatic granulations which appear black in‬ ✪ ‭color, these granulations partially cover the nucleus, they have heterogeneous content: an‬ ‭amorphous or granular material.‬ ‭2 types of mast cells in humans: It is a biochemical distinction depending on the protease content.‬ ‭ Mast cells which contain tryptase are not detected in the skin, however mast cells‬ ✪ ‭which have enzymatic equipment in tryptase and kimase can be detected in the skin and these mast‬ ‭cells are well represented in the skin. under the intestinal mucosa. This mast cell with this tryptase‬ ‭equipment and kimase is not highlighted at the level of the alveolar walls while the one which is‬ ‭only tryptase can be highlighted there. The morphology of the granules varies function of‬ ‭biochemical equipment. Retain the main differential criteria between these two types of mast cells.‬ ‭ These 2 types of mast cells intervene in immediate hypersensitivity. In fact both are capable of‬ ✪ ‭degranulation following immunoglobulin E bridging; they will be released mediators which are‬ ‭either performed such as histamine, heparin, proteases but also mediators which can be‬ ‭synthesized:lipids which derive from arachidonic acid like certain prostaglandins. It is all of these‬ ‭mediators which will induce the immediate hypersensitivity reaction.‬ ‭ Receptors for molecules are highlighted on the surface of the mast cell. of adhesion, and a‬ ✪ ‭receptor density for the stemcelf factor which is much more important compared to the basophil.‬ ‭ The maturation of these mast cells takes place in the tissue where it will perform its function and‬ ✪ ‭not at the level of the hematopoietic bone marrow unless its destiny is to remain there. So the‬ ‭Elements that will pass into the blood are immature, they are precursors engaged in a pathway of‬ ‭differentiation.‬ ‭ The maturation of these mast cells lasts 2/3 months in the final tissue and it is depending on the‬ ✪ ‭cytokine environment that we will have one of the two types of mast cells:the one which is tryptase‬ ‭or kimase and tryptase positive and there it is interleukin 4 which intervenes for differentiation‬ ‭towards a tryptase and kimase positive mast cell. Stemcel factor can be secreted by fibroblasts or‬ ‭endothelial cells.‬