Chemotactic effects of the complement-derived peptides C3a, C3ai and C5a (classical anaphylatoxin) on rabbit and guinea-pig polymorphonuclear leukocytes.

The complement-derived peptides C3a, C3ai and C5a (= classical anaphylatoxin) were purified from hog serum and examined for chemotactic activity on rabbit and guinea-pig polymorphonuclear leukocytes (PMN) with the Boyden chamber technique (with filters of 3,0 micrometer pore size). When media containing albumin or serum were used all peptides induced chemotaxis of both cell species. Only C3a showed a pronounced species dependence in that it was much more active on rabbit than on guinea-pig PMN. No gross differences were found between the influence of 0.5% BSA and 10% heated (56 degree, 30 min) homologous serum added to the medium. In the absence of protein chemotaxis did not occur.