anaphylatoxin
Low molecular weight substances generated by the activation of complement; the biologically active complement components are derived from C3, C4, and C5 and lead to increased vascular permeability as a result of the degranulation of primarily mast cells; release of mediators of immediate hypersensitivity (Type I), i.e., histamine, follows mast cell degranulation. SYN: anaphylotoxin. [anaphylaxis + toxin]

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an·a·phyl·a·tox·in .an-ə-.fil-ə-'täk-sən n a toxic substance postulated to be formed in blood serum treated with some bacterial polysaccharides in order to explain the anaphylaxis that results when the treated and modified serum is injected into experimental animals

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ana·phyl·a·tox·in (an″ə-filґə-tok″sin) a substance produced by complement activation that causes the release of histamine and other mediators of immediate hypersensitivity from basophils and mast cells, thereby producing signs and symptoms of immediate hypersensitivity (anaphylaxis) without involvement of IgE. The anaphylatoxins are low-molecular-weight complement cleavage products, C3a, C4a, and C5a, which bind to specific receptors on mast cells and basophils; C4a has comparatively weak anaphylatoxin activity; C5a is also a chemotactic factor for granulocytes and macrophages.

Medical dictionary. 2011.

Look at other dictionaries:

  • Anaphylatoxin — Anaphylatoxins, or anaphylotoxins, are fragments (C3a, C4a and C5a) that are produced during the pathways of the complement system.cite journal | author = Hugli TE | title = Biochemistry and biology of anaphylatoxins | journal = Complement |… …   Wikipedia

  • Anaphylatoxin — Anaphylatoxine sind Abbauprodukte des menschlichen Körpers. Es sind Proteine, aktivierte Teilkomplexe des Komplementsystems, die bei akuten allergischen Reaktionen durch Auslösung des Mastzellen Zerfalls Histamin freisetzen. Physiologie… …   Deutsch Wikipedia

  • anaphylatoxin — Originally used of an antigen that reacted with an IgE antibody thus precipitating reactions of anaphylaxis. Now restricted to defining a property of complement fragments C3a and C5a, both of which bind to the surfaces of mast cells and basophils …   Dictionary of molecular biology

  • anaphylatoxin — noun Any of several toxic substances that trigger anaphylaxis …   Wiktionary

  • Anaphylatoxin — Ana|phyla|toxi̱n [Kurzw. aus ↑Anaphylaxie u. ↑Toxin] s; s, e: der hypothetische Giftstoff (Anaphylaktogen) des eine Anaphylaxie erzeugenden Fremdeiweißes …   Das Wörterbuch medizinischer Fachausdrücke

  • anaphylatoxin — an·a·phyl·a·tox·in …   English syllables

  • anaphylatoxin — ˌanəˌfiləˈtäksə̇n noun ( s) Etymology: International Scientific Vocabulary anaphyla (from New Latin anaphylaxis) + toxin : a hypothetical substance formerly regarded as responsible for the symptoms of anaphylaxis …   Useful english dictionary

  • Anaphylatoxin receptors — The anaphylatoxin receptors are a group of G protein coupled receptors which bind anaphylatoxins.cite journal | author = Fukuoka Y, Nielsen LP, Hugli TE | title = Characterization of receptors to the anaphylatoxins on isolated cells | journal =… …   Wikipedia

  • anaphylatoxin inactivator — An α globulin (MW 300,000) which destroys the activity of the anaphylatoxic complement fragments. See anaphylatoxin. * * * (AI) a serum carboxypeptidase that destroys the anaphylatoxin activity of C3a, C4a, and C5a by removing C terminal arginyl… …   Medical dictionary

  • C3a receptor — The C3a receptor also known as complement component 3a receptor 1 (C3AR1) is a G protein coupled receptor protein involved in the complement system.cite journal | author = Roglic A, Prossnitz ER, Cavanagh SL, Pan Z, Zou A, Ye RD | title = cDNA… …   Wikipedia

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