Fig. 1. Sodium-glucose cotransport activity of proximal tubular cells in primary culture from vimentin-null mice (Vim^-/-; closed circles) and from wild-type littermates (Vim^+/+; open circles). The uptake of methyl--D-glucopyranoside (MGP) was evaluated in the presence of [¹⁴C]-MGP (0.5 µCi/ml) and appropriate concentrations of MGP. Na-dependent glucose uptake (insert) was calculated as the difference between MGP uptakes measured in the presence of sodium or glucamine. Eadie-Hofstee plot shows the V_max and the K_m of the MGP transport system of the two cell types. Data are means±s.e.m. of four separate cultures, experiments were performed in triplicate. Statistical analysis: ANOVA, Vim^-/- vs Vim^+/+ cells, P<0.005.