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Mast cells are especially numerous at sites of potential injury – the nose, mouth, and feet, internal body surfaces, and blood vessels. Non-mast cell histamine is found in several tissues, including the hypothalamus region of the brain, where it functions as a neurotransmitter.
A mast cell (also known as a mastocyte or a labrocyte [1]) is a resident cell of connective tissue that contains many granules rich in histamine and heparin.Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems.
per red blood cell 27-32 picograms Hexosephosphate P 1.4-5 × 10 −5: 0-2 × 10 −6: Histamine: 6.7-8.6 ...
When activated, mast cells rapidly release characteristic granules, rich in histamine and heparin, along with various hormonal mediators and chemokines, or chemotactic cytokines into the environment. Histamine dilates blood vessels, causing the characteristic signs of inflammation, and recruits neutrophils and macrophages. [5]
Basophils contain anticoagulant heparin, [8] which prevents blood from clotting too quickly. They also contain the vasodilator histamine, which promotes blood flow to tissues. They can be found in unusually high numbers at sites of ectoparasite infection (e.g., ticks). Like eosinophils, basophils play a role in both parasitic infections and ...
Clinically, H 1-antihistamines are used to treat allergic reactions and mast cell-related disorders. Sedation is a common side effect of H 1-antihistamines that readily cross the blood–brain barrier; some of these drugs, such as diphenhydramine and doxylamine, may therefore be used to treat insomnia.
Drop in blood pressure Swelling of the lips, throat, tongue or eyelids Some people with a severe form of alpha-gal syndrome may have trouble being around animals after developing the condition.
Histamine is a weak base (a compound able to react with a hydrogen ion to form an acid) that can link with acid groups within the granules of the mast cells. [8] The mechanism of the displacement theory. The crux of this theory lies in the assumption that histamine liberators release histamine by displacing it from cells.