Preabsorbing antibodies with aldosterone or a peptide reduces or blocks visualization.

MR-ir controls were established to ensure specificity of the antibodies. MA1-620 (A) and rMR1-18 1D5 (D) were visualized using SG chromogen. Tissue was incubated with 1 µMol aldosterone 30 min before addition of primary antibody. Aldosterone reduced observable chromogen visualization in neurons in the LA (B) when incubated with the antibody MA1-620. No observable difference was found when incubating aldosterone in tissue with the antibody rMR1-18 1D5 (E). Incubating the peptide used to generate the second antibody with the MA1-620 antibody (C) did not produce observable differences in chromogen visualization. Incubating the peptide in tissue with the antibody rMR1-18 1D5 completely blocked the antibody from binding to tissue (F). Scale bars = 200 µm for A–F, 5 µm for insets.