Fig. 2.

Effect of thrombospondin-1 on phosphatidylserine externalization, sphingomyelinase activation, and the generation of reactive oxygen species in human red blood cells. Representative histogram (Black line: 0 μg/mL TSP-1, orange line: 50 μg/mL TSP-1; a and means ± SEM. b of annexin V positive RBCs (n = 7) following 48-h incubation at 37 °C in Ringer’s solution containing 0–50 μg/mL TSP-1. *** indicate significant difference (P < 0.001) from the absence of TSP-1. Means ± SEM of annexin V positive RBCs following 48-h incubation in 50 μg/mL TSP-1 in the absence or presence of 1 mM amiloride (n = 27; c), 1 mM CaCl₂ (n = 8; d) or 1 μM sodium nitroprusside (n = 12; e). *** indicates significant difference (P < 0.001) from the absence of amiloride, CaCl₂ or sodium nitroprusside. Means ± SEM of the geometric means of DCFDA (n = 9; f) or ceramide-dependent (n = 14; g) fluorescence of RBCs following 48-h incubation without or with 50 μg/mL TSP-1. * indicates significant difference (P < 0.05) from the absence of TSP-1