Inhibition of thioglycollate-induced peritoneal inflammation. (a) Heparin and the various analogs at 0.5 (gray bars) or 1.25 mg per mouse (black bars) were injected intravenously 5 minutes after thioglycollate was injected intraperitoneally. The number of Gr-1–positive granulocytes in the peritoneal cavity was quantitated after 3 hours (see Methods). *Significant difference in neutrophil counts in the control mice that received standard heparin versus those injected with the indicated heparin derivatives. (b) Wild-type C57BL/6 and selectin-deficient mice were injected with heparin (0.5 mg) and thioglycollate. *Significant difference in neutrophil counts in mice treated with heparin (black bars) versus control mice that received only saline (gray bars). Each bar represents the average value ± SD; n = 5–10.