C3a (70-77) TFA

The direct interaction of C3a(70-77) with human mononuclear leukocytes in culture results in a concentration-dependent inhibition of the generation of LIF evoked by mitogens and by the antigen SK-SD.
C3a (70-77) induces histamine release and degranulation of rat mast cells, promotes contraction of guinea pig ileal tissue, and enhances vascular permeability in human skin. C3a (70-77) selectively desensitizes ileal smooth muscle to C3a but not to human C5a, a related anaphylatoxin. The cross-desensitization indicates a specific interaction of C3a (70-77) with cellular C3a binding sites.