Assessment of cardiac fibrosis after treatments with sacubitril/valsartan or valsartan in chemogenetic heart failure. A: representative cardiac tissue sections stained with Masson’s trichrome stain to detect interstitial fibrosis. B: quantitative data for measurements of interstitial fibrosis [control n = 3, d-amino acid oxidase (DAAO) n = 6, sacubitril/valsartan (Sac/val) n = 6, valsartan (Val) n = 5]. *P < 0.05 obtained by one-way ANOVA followed by Fisher’s least significant difference test. C: fibrosis-associated transcripts collagen α-1(I) chain (Col1a1), collagen α-1(III) chain (Col3a1), matrix metalloproteinase-2 (Mmp2), and transforming growth factor-β1 (Tgfb1) in cardiac tissue collected from rats infected with control virus or with DAAO virus treated with vehicle, sacubitril/valsartan, or valsartan alone (control n = 3, DAAO n = 6, Sac/val n = 6, Val n = 5). *P < 0.05, **P < 0.01, ****P < 0.0001 obtained by one-way ANOVA with Šídák’s multiple-comparison test. Data are represented as means ± SE.