Erythrocyte density after oxygenation–deoxygenation cycles in the presence of various cytokines.

Cells were incubated in the presence or absence of 500 nM ET-1, 20 ng/mL (370 nM) IL-10, 20 ng/mL (2.6 nM) RANTES, and 200 nM PAF for 5 hours at 37°C in plasmalike buffer (as described in “Materials and methods”). B, baseline; C, control. Baseline represents the cell density at time 0. Densities were measured using 1.1 g/mL phthalate oil solution. Values are mean ± SE of 3 experiments. *P < .004 (normal cells vs control); **P < .03 (Duffy-negative red cells vs control).