These protein fragments (C3a and C5a) are potent inflammatory mediators and also act as anaphylatoxins
, directly triggering mast cells.
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 .
C3a, C4a and C5a, known as anaphylatoxins
, can release vasoactive amines and lysosomal enzymes, enhance vascular permeability, and cause smooth muscle to contract (Guo and Ward 2005).
Although inhibition of the complement system is an absolute necessity for normal pregnancy, there is an increase in the concentrations of the anaphylatoxins
C3a, C4a and C5a in the maternal circulation (1).
Histamine-releasing factors from macrophages (4) or T lymphocytes (5) and anaphylatoxins
from complement system activation also lead to activation and subsequent degranulation of mast cells (6).
In patients with RA, complexes of antibodies containing rheumatoid factor form in the blood like iles flottant; they become trapped in joint spaces, joint cells try to get rid of the unwanted debris, cry havoc, and let loose the dogs of inflammation: anaphylatoxins
C3a, C5a, and eicosanoids, etc.
Characterization of complement anaphylatoxins
and their biological responses.
Evolution of anaphylatoxins
, their diversity and novel roles in innate immunity: Insights from the study of fish complement (Review).
A similarly comprehensive and well-written review covers the anaphylatoxins
, their receptors, and potential therapeutic drugs that may affect these biological activities.
We now appreciate that cytokines are important mediators of inflammation in RA but are downstream of the primary insults: immune complexes and anaphylatoxins
At that time, CPU was assumed to participate in the processing of bioactive peptides such bradykinin and anaphylatoxins
by analogy with CPN, and a possible role in fibrinolysis was suggested (2, 4-6).
C3a, together with C4a and C5a, the small fragments of C3, C4, and C5, respectively, are called the complement anaphylatoxins