The AT7/Mas receptor protein expression was significantly reduced in the dorsal medulla of 0.5- and 1.8-Year old betamethasone exposed (BMX) animals. Upper panel: Western blots for Mas and AT1 receptors, as well as β-Actin expression in the dorsal medulla from 0.5 and 1.8 year olds. Quantification of receptor expression revealed reduced levels of the Mas protein at both ages (middle panel, left) and the protein band was abolished by preabsorption of the primary antibody with the antigenic peptide (middle panel, right). There was no reduction in AT1 receptor expression (lower panel, left) and the protein band was diminished by preabsorption with the antigenic peptide (lower panel, right). Mas and AT1 receptor densities were normalized to β-Actin. Mas protein was detected at 50 kDa, AT1 at 40 kDa, and β-Actin at 42 kDa. Data are mean ± SEM [0.5-Year: N = 4 BMX; N = 3 control and 1.8-Year: N = 3 BMX; N = 3 control]; *P < 0.05 vs. control