Figure 5. In vitro exposure to aldosterone (3 nm) up-regulates mRNA expression of βENaC, γENaC and SGK1 in L/L and WT animals.

Depicted, are results from one set of real-time quantitative PCR experiments on colon tissue preparations from four wild-type (WT) and four L/L animals processed in parallel. Prior to RNA extraction, the same tissue preparations had been studied in Ussing chamber experiments, as shown in Fig. 3, to confirm functional up-regulation of ENaC-mediated Na⁺ transport by aldosterone. Tissues were either treated with 3 nm aldosterone (Aldo) or with vehicle (control). Numbers (1–4) correspond to the four WT and four L/L animals used and indicate corresponding values in the Aldo and control groups. Exposure to 3 nm aldosterone for 8.5 h resulted in an up-regulation of the mRNAs for βENaC, γENaC, SGK1, but not for αENaC.