THE EFFECT OF CYCLIC-GMP AND CYCLIC-AMP ON MIGRATION BY ELECTROPORATED HUMAN NEUTROPHILS

Human neutrophils retain the ability to migrate when they are electroporated; this enables the study of potential mediators by direct application to the cell interior. Cyclic GMP strongly enhances random migration by electroporated human neutrophils. The effect is maximal at a concentration of 10 muM. The potentiating effect of cGMP is chemokinetic. Chemotaxis of electroporated neutrophils activated by formylmethionylleucylphenylalanine (fMLP) is stimulated by cGMP at concentrations up to 10 muM; higher concentrations inhibit chemotaxis. Cyclic AMP resembles cGMP in that both activation and inhibition may occur. However, activation occurs over a very small concentration range, and inhibition is a predominant feature. Cyclic nucleotide-activated migration is dependent on Ca2+, in contrast with activation of migration by fMLP.