Search results
Results From The WOW.Com Content Network
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.
Although histamine is small compared to other biological molecules (containing only 17 atoms), it plays an important role in the body. It is known to be involved in 23 different physiological functions. Histamine is known to be involved in many physiological functions because of its chemical properties that allow it to be versatile in binding.
Degranulation in mast cells is part of an inflammatory response, and substances such as histamine are released. Granules from mast cells mediate processes such as "vasodilation, vascular homeostasis, innate and adaptive immune responses, angiogenesis, and venom detoxification."
They also produce compounds that coordinate immune responses, including histamine and serotonin that induce inflammation, and heparin that prevents blood clotting, [3] although there are less than that found in mast cell granules. [4]
Serotonin (/ ˌ s ɛr ə ˈ t oʊ n ɪ n, ˌ s ɪər ə-/) [6] [7] [8] or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter.Its biological function is complex, touching on diverse functions including mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vasoconstriction.
Histamine receptors are proteins that bind with histamine, a neurotransmitter involved in various physiological processes. There are four main types: H1, H2, H3, and H4. H1 receptors are linked to allergic responses, H2 to gastric acid regulation, H3 to neurotransmitter release modulation, and H4 to immune system function.
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.
The 7 general serotonin receptor classes include a total of 14 known serotonin receptors. [9] The 15th receptor 5-HT 1P has been distinguished on the basis of functional and radioligand binding studies, its existence has never been definitely affirmed or refuted. [10] [11] The specific types have been characterized as follows: [12] [13] [14]