Test of potential molecules capable of inducing erythrocyte SphK1 activity. (A) SphK1 activity in cultured primary erythrocytes from WT mice treated with endothelin-1 (100 nM), angiotensin II (100 nM), tumor necrosis factor-α (50 ng/mL), sphingosine 1-phosphate (100 nM), and NECA (10 μM). (B) Induction of erythrocyte SphK1 activity by NECA in a time-dependent manner. (C) Dose-dependent erythrocyte SphK1 activation by NECA treatment of 30 min. Values shown represent the mean ± SEM (n = 3∼5 for each group). *P < .05 NECA vs control.