Comparison of SA-, anti-Fas–, and PMA-mediated intracellular release of H₂O₂ as determined by augmented R123 fluorescence (FL 1). Eosinophils were stimulated with medium control or SA (50 μmol/L) or anti-Fas (2 μg/mL) for 19 hours, thereafter the cells were labeled with DHR (for details see Materials and Methods). Stimulation with PMA (10⁻⁷ mol/L) served as positive control. One representative of 4 experiments is shown. The thin line represents the medium control, whereas the bold line represents the stimulus indicated.