Figure 3. Chromium Induces Changes in Leukocyte Subsets after Acute Cr(VI) Inhalation.

BALBc mice were exposed to 50 µL of 1.2 mg/mL basic zinc chromate over a period of 24 hrs. A) The number of living cells present in BAL fluid were quantified for 5 animals in each experiment, and the change in cell number from the 0 hr time point was determined. Data are the mean ± SEM of two independent experiments, n=5–10 animals/time point. * indicates a statistically significant difference from time 0 at p<0.05. B) Representative dot plots of forward scatter/side scatter (FSC/SSC), GR-1/FcεRIα staining, and CD3/CD11c staining from cells in the BAL fluid collected at indicated time points. Blue and red regions on FSC/SSC plots highlight the location of neutrophils and macrophages, respectively. Blue and red boxes corresponding to these same two populations are shown on the fluorescence plots. C) Changes in total neutrophil and D) macrophage cell numbers at 0–24 hrs post-Cr(VI) exposure. Data are the mean ± SEM of 5 mice from a representative experiment. * denotes a statistically significant difference from time 0 at p<0.01. E) Quantification and representative images (40× original magnification) of cells in the BAL fluid and stained with H&E. Macrophages and neutrophils are indicated be * and arrows respectively. Data are the mean ± SEM of 3 Cr(VI)-treated and 2-saline treated animals 24 hrs after exposure * denotes a statistically significant difference from saline at p<0.05.