Figure 1.
Neutrophils which are mobilized from the bone marrow must cross the sinusoidal endothelium. (a) Electron micrograph illustrating the transcellular migration of a neutrophil (arrow) through murine bone marrow sinusoidal endothelium (arrowheads) into the lumen following infusion of 0·1 mm of the chemokine (C-X-C motif) receptor 4 (CXCR4) antagonist AMD3100 (Sigma Aldrich, Poole, UK) for 10 min, followed by 20 min with buffer alone, prior to perfusion fixation and preparation for transmission electron microscopy. (b) Migration of a neutrophil across the sinusoidal endothelium following infusion of macrophage inflammatory protein (MIP)-2. Rat femoral bone marrow was infused with MIP-2 (3 nmol/l) for 10 min, followed by 20 min with buffer alone, prior to perfusion fixation and preparation for scanning electron microscopy.