Effect of catalytic antioxidant treatment on SM-mediated leukopenia. Whole blood was analyzed using a hematology analyzer for WBC levels. WBC counts in whole blood samples were measured at euthanasia. White blood cell counts over time are presented in panels A, C, and E and were analyzed by two-way ANOVA with Dunnetts’ post-test, comparing each group over time to Sham PBS *Significantly differs from sham exposed. Total WBC, neutrophil, and lymphocyte counts collected at euthanasia from 48 h experiments are presented in panels B, D, and F. Two-way ANOVA with Newman–Keuls multiple comparisons test corrected for multiple comparisons were performed to determine differences between these groups, different letters represent significant differences (P < .05). (A–F) Sham PBS/Sham 10150 n = 5/time point, SM PBS 6 h n = 15, SM PBS 12 h n = 14, SM PBS 18 h n = 17, SM PBS 24 h n = 13, SM PBS 48 h n = 13, SM 10150 6 h n = 14, SM 10150 12 h n = 14, SM 10150 18 h n = 16, SM 10150 24 h n = 11, SM 10150 24 h n = 13.