In:
The Journal of Immunology, The American Association of Immunologists, Vol. 120, No. 5 ( 1978-05-01), p. 1767-1768
Abstract:
Human C3a anaphylatoxin, the 77-residue polypeptide split from the NH2-terminus of the alpha chain of C3, causes contraction of smooth muscle, release of histamine from mast cells, and increase in vascular permeability. The 76-residue peptide formed by removing the COOH-terminal arginine from C3a shows none of these activities. In this study, oligopeptides from the COOH-terminus of C3a were synthesized by the solid-phase method and found to exhibit these inflammatory activities and to display the specificity of C3a. At a molar dose 50 times that required for C3a, the octapeptide with the sequence Ala-Ser-His-Leu-Gly-Leu-Ala-Arg stimulated histamine-mediated contraction of guinea pig ileum strips, released vasoactive amines from rat mast cells, and increased the vascular permeability of human and guinea pig skin. Since it cross-desensitized the ileum to C3a but not to C5a or bradykinin, the octapeptide specifically mimicked the action of C3a. It was not chemotactic for human neutrophils over a broad range of concentrations.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.120.5.1767.c
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
1978
detail.hit.zdb_id:
1475085-5
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