Chemotaxis of radiolabeled equine neutrophils

Abstract

SUMMARY A method for the isolation of equine neutrophils was developed using metrizamide cushions. A purity of > 95% was routinely obtained with > 90% viability. These cells were radiolabeled and tested for their chemotactic response in Boyden chambers to zymosan-activated equine serum, the partially purified equine complement component C5a, and formyl- l -methionyl- l -leucyl- l -phenylalanine. The time and ionic requirements for chemotaxis of radiolabeled equine neutrophils were investigated and maximal movement was observed at 2 hours’ incubation and 1.0 m M Ca and 0.5 m M Mg. Dinitrophenol in a concentration range of 10 −2 to 10 −6 M also inhibited cell movement. A Zigmond-Hirsch checkerboard assay demonstrated the pronounced chemotactic activity of zymosan-activated equine serum and the partially purified equine C5a. The equine neutrophil did not respond to formyl- l -methionyl- l -leucyl- l -phenylalanine.