Figure 4.

PE-induced permeabilization of enterocytes revealed by LY. Mucosal explants cultured for 1 h in the absence (A) or presence of 2 mM of LC (B), DG (C) or C₁₂E₉ (D), and in the presence of 0.5 mg/ml of the fluorescent polar tracer LY. All images shown were captured at identical settings of the microscope. A: A narrow line of punctate labeling of LY is seen just below the enterocyte brush border (arrow and enlarged insert), but diffuse cytoplasmic staining of the cytosol is weak or absent. LY is also seen in the paracellular space between enterocytes and, most strongly, in areas of the lamina propria. B-D: LC, DG, and C₁₂E₉ all caused a diffuse cytoplasmic staining of the enterocytes in a mosaic pattern, but subapical punctae were not detected. The images shown of each situation are representative of at least 5 images. Bars: 20 µm.