Feline polymorphonuclear leukocytes respond chemotactically to leukotriene B4 and activated serum but not to F-Met-Leu-Phe.

The chemotactic response of feline polymorphonuclear leukocytes (PMNs) to three types of chemoattractants was studied. Feline PMNs responded to leukotriene B4 as well as to agarose-activated autologous and homologous serum. However, no response was obtained to N-formylmethionylleucylphenylalanine (FMLP), and four similar peptides that activate the FMLP receptor (N-formylnorleucylleucylphenylalanine, N-formylmethionylphenylalanine, methionylleucylphenylalanine, and pepstatin). Thus, feline PMNs are similar to equine, porcine, bovine and canine PMNs which also do not respond chemotactically to these peptides.