Figure 2.

Conjugated bilirubin activates mouse ENaC in Xenopus oocytes. A and B, oocytes expressing WT ENaC were perfused with 5 mm bilirubin conjugated with either glucuronic acid (c-bilirubin) or taurine (t-bilirubin) and then washed out before the addition of 10 μm amiloride. C, concentration-dependent activation of ENaC by bilirubin conjugates. The basal amiloride-sensitive current was −2.7 ± 1.9 μA (n = 14). Data are mean ± S.D. (n = 5–9). Lack of saturation suggests an EC₅₀ > 1 mm. ****, p < 0.0001 by two-way ANOVA with Sidak's multiple-comparison post hoc test.