anaphylatoxin


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anaphylatoxin

 [an″ah-fil´ah-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.

an·a·phyl·a·tox·in

(an'ă-fil-ă-tok'sin),
Low molecular weight cleavage products (C3a, C4a, and C5a); generated by the activation of the complement cascade. They are proinflammatory; can cause permeability, smooth muscle contraction, and mask cell degranulation.
Synonym(s): anaphylotoxin
[anaphylaxis + toxin]

anaphylatoxin

/ana·phyl·a·tox·in/ (-fil´ah-tok″sin) a substance produced in blood serum during complement fixation which serves as a mediator of inflammation by inducing mast cell degranulation and histamine release; on injection into animals, it causes anaphylactic shock.

anaphylatoxin

[an′əfī′lətok′sin]
a fragment (C3a, C4a, or C5a) that is produced during the pathways of the complement system. Along with other mechanisms, it mediates changes in mast cells leading to the release of histamine and other immunoreactive or inflammatory reactive substances. If the degranulation of mast cells is too strong, it can cause allergic reactions.

anaphylatoxin

(1) Any antigen that reacts with an IgE and precipitates an anaphylactic reaction by stimulating histamine release.
(2) Activated complement fragments (C3a, C4a and C5a) that bind to mast cells and basophils and trigger the release of inflammatory mediators.

an·a·phyl·a·tox·in

, anaphylotoxin (an'ă-fil'ă-tok'sin, an'ă-fil'ō-tok'sin)
1. A substance postulated to be the immediate cause of anaphylactic shock and that is assumed to result from the in vivo combination of specific antibody and the specific sensitizing material.
2. The small fragment (C3a) split from the third component (C3) of complement, which produces a local wheal following intracutaneous injection.

anaphylatoxin

Any substance that can directly cause degranulation of MAST CELLS thereby bringing about an acute allergic reaction.

anaphylatoxin

a substance produced in blood serum when complement is activated; serves as a mediator of inflammation by inducing mast cell degranulation, histamine release and increased vascular permeability, and on injection into animals, it causes anaphylactic shock.

anaphylatoxin inhibitor
a specific serum carboxypeptidase, one of the complement proteins.
References in periodicals archive ?
demonstrated that the anaphylatoxins C3a are essential for liver regeneration.
Carboxypeptidase N was reported to disrupt the activity of the anaphylatoxin C3a because ASP cannot mediate many of the proinflammatory activities associated with C3a (17, 18).
Subsequent steps of the complement cascade lead to formation of several effector molecules, including opsonization of pathogens, formation of the membrane attack complex inducing osmotic lysis of cells, and recruitment and activation of inflammatory cells by the anaphylatoxins complement C3a and C5a (25).
Through interactions with C3a and C5a receptors, these anaphylatoxins trigger the production of pro-inflammatory innate immune proteins, such as cytokines, in leukocytes and thus contribute to inflammation (Cohen et al.
In the mammalian cell, Anaphylatoxins are able to trigger j) degranulation (release of substances) of endothelial cells, mast cells or phagocytes, which produce a local inflammatory response [17].
We identified these two peaks, with mass to charge ratios (m/z) of 9,100 and 10,100, as anaphylatoxin C3a and calgranulin A by additional mass spectral investigation using liquid chromatography coupled to mass spectrometry.
Objective: To search for anaphylatoxin activity in plasma during episodes of erythema marginatum, and to evaluate the histology of erythema marginatum by electron microscopy and immunohistologic techniques.
Remarkably, these peptide signals in oysters, mud crabs, and cyanobacteria are all structurally related to the carboxy-terminal sequence of mammalian C5a anaphylatoxin, a potent white blood cell chemoattractant.
Thrombin is a serine protease that enhances vascular permeability, activates and degranulates mast cells, and induces generation of anaphylatoxin C5a.
Dialysis leukopenia, hypoxemia, and anaphylatoxin formation: effect of membrane, bath, and citrate anticoagulation.
Aspirin-III blocks signals sent by both: immune complexes via FCR, and anaphylatoxin via C5 receptors.
C5 derived peptide induces increased vascular hypermeability, anaphylatoxin activity, limbal flux, uveal leakages which perpetuates leakage of complement components and IgG into the eye.