NPPB and familial dilated cardiomyopathy: Db/db mice exhibited a typical DCM phenotype at the 24th week of the disease that was primarily characterized by enlarged ventricles, increased cardiac weight and heart/tibia ratio, upregulated atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels, overt cardiomyocyte hypertrophy, myocardial fibrosis and decreased microvessel density (Figure 2A-E).