CORRELATION OF THE BIOLOGIC EFFECTS AND BINDING OF CYTOCHALASINS TO HUMAN POLYMORPHONUCLEAR LEUKOCYTES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 57  (3) , 399-405
Abstract
Treatment of human PMNs with cytochalasins (CE, CD, CB and H2CB) results in alteration of cell morphology and inhibition of cell motility. Morphological changes are similar to those reported for nonamoeboid fibroblasts-rounding, zeiosis and arborization. Mean cell velocity of PMNs, as measured by quantitative analysis of time-lapse videotape recordings, was reduced to 0.1 .mu.m/min (control, 7.3 .+-. 4.2 .mu.m/min). Phagocytosis by PMNs, as measured by phagocytosis of latex beads, was inhibited by 75%. The relative potency of the cytochalasins for inducing morphological change or for inhibiting locomotion and phagocytosis is similar to their relative potencies for affecting nonamoeboid cells: CE > CD > CB .gtoreq. H2CB. Quantitative binding of 3H-CB to purified PMNs under equilibrium conditions reveal 2 types of specific CB binding sites: high-affinity sites (KD .apprx. 3 .times. 10-7M, 3 .times. 106 sites/cell) and low affinity sites (KD .apprx. 2 .times. 10-6M). The relative affinities of the cytochalasins for the high-affinity and low-affinity CB binding sites parallel their relative potencies for inducing biologic effects (i.e. CE > CE > CB .gtoreq. H2CB).