POLYMORPHONUCLEAR LEUKOCYTE MEMBRANE-STIMULATED OXIDATIVE METABOLIC-ACTIVITY - THE EFFECT OF DIVALENT-CATIONS AND CYTOCHALASINS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 44  (4) , 847-858
Abstract
The effect of divalent cations and cytochalasins on the oxidative metabolic response of human polymorphonuclear leukocytes (PMNL) following membrane stimulation by opsonized zymosan, phorbol myristate acetate (PMA), digitonin and n-formyl-methionyl-leucyl-phenylalanine (FMLP) was investigated using several techniques. For optimal ferricytochrome C reduction, O2 consumption, luminol- and lucingenin-dependent chemiluminescence by PMNL on exposure to pop opsonized zymosan, extracellular Mg was necessary. FMLP- and digitonin-induced PMNL metabolic activities were less dependent on extracellular MG than on Ca. Phorbol myristate acetate-induced PMNL oxidative metabolic activity occurred independently of extracellular MG and Ca concentration. Incubation of PMNL with cytochalasins B and E had little effect on PMA-induced metabolic activity, enhanced FMLP-induced metabolic activity, enhanced FMLP-induced metabolic activity but inhibited digitonin-induced metabolic activity. Investigation of zymosan-induced PMNL metabolic activity after incubation with cytochasins demonstrated a dissociation between the different parameters of metabolic activity measured. PMNL oxidative metabolism apparently can be activated by at least 2 different mechanisms depending on the stimulus used. These mechanisms can in part be differentiated by their dependence on extracellular divalent cations.