FIGURE 1.

Aldosterone stimulates inner medullary ET-1 expression in rat. A, IMCD cells were acutely isolated from rat and treated with vehicle (open bars) or 1 μm aldosterone (closed bars) for 1 h ex vivo. Levels of edn1 and sgk1 mRNA were determined by QPCR, normalized to β-actin, and expressed as -fold change relative to vehicle ± S.E. (n = 4, *, p < 0.05, **, p < 0.005). B, inner medullary ET-1 peptide levels were measured in kidneys isolated from rats injected with aldosterone (1 mg kg⁻¹ body weight, intraperitoneally) or vehicle for 2 h. Inner medullary ET-1 peptide levels were determined by enzyme-linked immunosorbent assay and normalized to total protein content. Values are expressed as ET-1 (picograms/mg of protein) ± S.E. (n ≥ 8 per group; *, p < 0.05).