Erythrocyte profile of sickle cells expressed as percentage of cells below phthalate ester (denser cells).

Cells were incubated in the presence or absence of ET-1 for 5 hours at 37°C in plasmalike buffer connected with a humidifier–gas regulator that cycled 15% O₂/5% CO₂ (3 minutes) or 5% CO₂ (7 minutes). All gases were balanced with N₂. Baseline represents the cell density profiles at time 0. ET-1, 300 nM. Values are mean ± SE of 3 experiments.