Figure 4: Up-regulation of hypertrophy markers in AR animals. LV mRNA levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), endothelin-1 (ET-1) and c-Fos were evaluated as described in the Material and methods section. Results are reported in arbitrary units as mean ± SEM (n = 13–15/group). Untreated sham (sham operated animals) group mRNA levels were normalized to 1. Two-way ANOVA statistical analysis results are displayed below each graph. D X T: disease and metformin treatment interaction.