Cells found predominantly in connective tissue, although a specialised population of mast cells is found in mucosal sites (e.g. the gut). Following degranulation, mast cells release preformed and newly synthesised mediators of inflammation, including histamine.
Fixed (noncirculating) cells that are present in many different kinds of body tissues. When two IgE molecules of the same antibody “dock” at adjacent receptor sites on a mast cell, then (the two IgE molecules) capture an allergen (e.g., a particle of pollen) between them, a chemical-energetic signal is sent to the interior (inside mast cell) portion of receptor molecules, which causes that interior portion of molecule to change (i.e., transduction). That signal transduction causes a protein named “syk” to set off a chemical chain reaction inside the mast cell; thereby causing that mast cell to release leukotrienes, histamine, serotonin, bradykinin, and “slow reacting substance.” Release of these chemicals into the body causes the blood vessels to become more permeable (leaky) and causes the nose to run, itchy and watery eyes. These chemicals also cause smooth muscle contraction—causing sneezing, breath constriction coughing, wheezing, etc.
These are a group of cells that line the capillaries of tissues that come in contact with the outside, like skin, sinus, and lung mucosa. They, like their first cousin basophils, are produced in the red bone marrow and migrate to the appropriate tissues, where they stay. They bind IgE, supply the histamine and heparin response that gives you a healing inflammation, and cause allergies.
A granulocyte found in tissue. The contents of along with those of the basophils cause the symptoms of allergies.
A tissue cell, often found around blood vessels, which produces histamine, heparin, leukotrienes, and platelet activation factor. Important in immediate hypersensitivity reactions.
A large cell in connective tissue, which carries histamine and reacts to allergens.
Large connective tissue cell that contains histamine, heparin, serotonin, and bradykinin, which are released in response to injury, inflammation, or allergic reaction.
A tissue cell that is part of the immune system and originates as a stem cell. Mast cells have an important role in the body’s immune response that occurs when foreign substances are perceived by the immune system to be harmful. The mast cells contain chemicals that are responsible for the symptoms of allergies. When allergens enter the body, they attach to antibodies located on the surface of mast cells. This attachment releases a signal that causes the mast cells to release certain chemicals, including histamine, that cause the symptoms of an allergy.
A large cell in connective tissue with many coarse cytoplasmic granules. These granules contain the chemicals heparin, histamine, and serotonin, which are released during inflammation and allergic responses.
Round or oval cells found predominantly in the loose connective tissue. They contain histamine and heparin, and carry immunoglobulin E, the antibody which plays a predominant part in allergic reactions. Although known to play a part in inflammatory reactions, allergy, and hypersensitivity, their precise function in health and disease is still not clear.
A large tissue cell resembling a basophil, which is essential for inflammatory reactions mediated by immunoglobulin E (IgE) but does not circulate in the blood. Mast cells are present throughout the body in connective tissue, but are concentrated beneath the skin and the mucous membranes of the respiratory and digestive tracts. Mast cells are covered With IgE molecules, which bind with foreign antigens and stimulate degranulation, releasing such mediators as histamine, prostaglandins, leukotrienes, and proteinases from densely packed granules within the cytoplasm. These mediators produce type I (immediate) hypersensitivity reactions (e.g., urticaria, allergic rhinitis, asthma, angioedema, and systemic anaphylaxis).
A specific kind of immune system cell that presents immunoglobulin E (IgE) on its cell surface and plays a role in allergic reactions and asthma by releasing histamine and other substances from specialized granules within its cells.
A variety of cell that holds a significant role in allergic reactions. During an allergic response, antibodies (proteins generated by the immune system to counteract allergens) adhere to mast cells. These cells rupture and discharge a substance known as histamine, which triggers an inflammatory reaction in nearby tissues. Consequently, this process gives rise to numerous symptoms observed in allergic conditions.