Effect of inhibiting l-selectin sheddase on neutrophil mobilization from the bone marrow. The rat femoral bone marrow was perfused as before for a total of 100 minutes. At t = 10 minutes the bone marrow was infused with KD-IX-73-4 (50 μg/mL) or vehicle for 5 minutes, followed by a 10-minute infusion of vehicle or MIP-2 (1 nM). (A) Expression of l-selectin on neutrophils mobilized in response to vehicle or MIP-2 in the presence or absence of KD-IX-73-4 is shown by the solid histograms. Binding of an isotype-matched control mAb is shown by the dotted line. Histograms are representative of n = 3 to 7 separate perfusions with staining performed in triplicate. (B) Combined results are expressed as the mean of the specific geomeans ± SEMs. ^*P < .05. (C) The total number of neutrophils released during the 100-minute perfusion in the presence and absence of KD-IX-73-4 in response to vehicle or MIP-2, mean ± SEM (n = 4-7 separate perfusions). NS indicates not significant.