Fig. 6. Effect of IS on RBC GSH levels. RBC obtained from healthy subjects (n=10) were treated with different concentrations of IS (0.01, 0.09, 0.17 mM) for 24h at 37^oC in an incubator with controlled oxygen under normoxic (21% O₂) (white bars) or hypoxic (5% O₂) (black bars) conditions. Control RBC (CON-RBC) were incubated with TRIS-Glc-BSA in normoxia and hypoxia. Thiol Tracker-labeled cells were analyzed by flow cytometry and results were represented as Relative % against CON-RBC in normoxia. *p<0.05; ***p<0.001 between normoxia versus hypoxia in the same group. ##p<0.01; ###p<0.001 between CON-RBC versus IS concentration in the same group (normoxia vs normoxia; hypoxia vs hypoxia). ^Δ p<0.05; ^ΔΔΔ p<0.001 variation on GSH levels between IS concentrations and controls in normoxia and hypoxia.