FIGURE 3.

Infection of rRA2 decreases whole-cell Na⁺ currents in GFP(+) H441 cells. Characteristic whole-cell current traces in a control non-inoculated H441 cell before (A) and after (B) perfusion with 10 μm amiloride. The amiloride-sensitive currents (C) were calculated by digitally subtracting the current remaining after perfusion of amiloride from that before amiloride perfusion. D and E, whole-cell basal (D) and amiloride-sensitive (E) Na⁺ current I-V relationships of non-inoculated cells (squares), cells exposed to rRA2 but showing no green fluorescence (GFP(-), triangles) and exposed to rRA2 and showing green fluorescence (GFP(+), circles). Cells were held at -40 mV and the currents (in pA) were normalized for surface area by dividing them by capacitance (in pF), then plotted to their corresponding driving potentials as described under “Materials and Methods.” Values are the means ± S.E., n = 6-8 per group. F, comparison of whole-cell basal (solid) and amiloride-sensitive (striped bar) current densities at -60 mV of control non-inoculated cells, GFP(-), and GFP(+) cells. Values are the means ± S.E., n = 6 to 8 for each group. Measurements were obtained 3-6 days post-infection (p < 0.05 (^*) and p < 0.01 (^**) are from the corresponding value of non-inoculated cells, n = 6-8 for each group, m.o.i. = 1).