Histamine Release by Chemotactic, Formyl Methionine-Containing Peptides Free

Certain formyl dipeptides and tripeptides containing methionine released histamine from human basophils at concentrations of 10^-4 to 10^-7 M. However, N-formyl amino acids did not release histamine. Tripeptides, in general, were more active than dipeptides. An acyl group was required for histamine release although an N-terminal position for Met was not essential. Histamine release from human basophils by these peptides correlated well with their chemotactic activity for rabbit leukocytes.