Sinusoidal neutrophil adhesion is reversible by blocking CD44–HA interactions. 4 h after i.v. LPS injection, intravital microscopy was used to visualize the sinusoids of WT mice. After a baseline recording was made, 20 μg anti-CD44 mAb was injected via the right jugular vein, and subsequent recordings were made at 15-min intervals for an additional 45 min. The number of adherent leukocytes per field of view (A) and the percentage of perfused sinusoids (B) were measured. Data are presented as the arithmetic mean ± SEM of at least five animals. *, P < 0.05 relative to 4 h LPS (before antibody treatment).