Activation of the rabbit polymorphonuclear leukocyte membrane "Na+, K+"-ATPase by chemotactic factor

Abstract

Addition of the synthetic chemotactic factor, formyl-methionyl-leucyl-phenylalanine (F-Met-Leu-Phe) to medium containing magnesium, sodium and potassium results in a doubling of the Na+,K+-ATPase activity of the plasma membrane fraction from polymorphonuclear leukocytes (PMN). This activation is sensitive to ouabain inhibition and is dose dependent, maximal activity occurring at 10-9 M F-Met-Leu-PHe. Equivalent activation was observed with the nonformylated derivative Met-Leu-Phe at 10-6 M. The dipeptide, carbobenzoxy-methionyl-phenylalanine, which acts as an antagonist for F-Met-Leu-Phe, prevents the stimulation of the ''Na+,K+''-ATPase by F-Met-Leu-Phe.