Figure 9.

Representative effects of gadolinium on an ENaC-expressing oocyte. (Top) Addition of 10, 50, and 100 μM Gd⁺³ caused a small and time dependent decrease of C_m. These effects were poorly reversible and were unlikely representative of actual area changes (see text). (Bottom) Effects on membrane conductance. As previously observed, the majority of the conductance is attributed to ENaC and is furthermore amiloride sensitive. Sequential addition of Gd⁺³ at 10, 50, and 100 μM caused a slow decrease of the amiloride sensitive conductance. The majority of these effects were observed with 10 μM Gd⁺³ and were time dependent in that very little additional changes were observed by increasing the [Gd⁺³]. Both effects were only partially reversible within the 1-h washout period. Data representative of nine experiments. See Table I for summary.