Figure 3.

Time- and dose-dependent effects of toluene diisocyanate (TDI) on FITC-VDBP uptake in RLE-6TN cells. RLE-6TN cells were preincubated with 1 mM TDI for the indicated times and then incubated in serum-free medium with 400 nM FITC-VDBP at 37℃ for 2 h (A). RLE-6TN cells were preincubated with the indicated doses of TDI for 6 h and then incubated in serum-free medium with 400 nM FITC-VDBP at 37℃ for 2 h. Fluorescence was examined using a fluorescence microscope. Scale bar, 20 µm. In the lower panel, fluorescent intensities of the cells were counted using an image browser, and data are presented as percent intensity (B). All data are representative of three independent experiments. Values represent the means ± SEM. ^*P < 0.05, ^**P < 0.001 vs. control.