Fig. 1. Morphology of neutrophils exposed to chemotactic peptide or to colchicine without or with preincubation with taxol or the Rho-kinase inhibitor Y-27632. Neutrophils were preincubated for 30 minutes at 37°C followed by a further incubation either in medium for 30 minutes (control) or in medium containing 1 nM fNLPNTL for 1 or 10 minutes or in 10 µM colchicine for 30 minutes. Alternatively, cells were preincubated for 30 minutes in the presence of 10 µM Y-27632 or with 1 µM taxol followed by addition of colchicine (10 µM) and a further incubation for 30 minutes. Cells were fixed with glutaraldehyde and examined using Nomarski optics. Bar, 10 µm. Asterisks indicate typical examples of spherical cells in the control panel and of non-polar cells with ruffles in the panel showing cells stimulated for one minute with fNLPNTL. Arrows indicate the front with protrusions (pseudopods, ruffles), arrowheads the contracted tail (uropod) of typical examples of polarized cells. Note that the cells polarized by colchicine show less ruffling at the front than those stimulated with fNLPNTL