This study tested the hypothesis that entresto therapy effectively protected heart and lung against cardiopulmonary syndrome (CPS) caused by transverse aortic constriction (TAC) in rat. Adult-Male SD rats (n = 36) were equally categorized into group 1 [sham-operated control (SC)], group 2 [SC + enalapril (7 mg/kg/day) since day-28 after TAC induction], group 3 [SC + entresto (30 mg/kg/day) since day-14 after TAC induction], group 4 (TAC only), group 5 (TAC + enalapril) and group 6 (TAC + entresto) and euthanized at day 60 after TAC induction. By day 60, the left-ventricular (LV) ejection fraction was significantly lower in group 4 than in other groups and significantly lower in groups 5 and 6 than in groups 1 to 3, whereas the ratios of heart and lung weights to tibial-length as well as the right-ventricular-systolic blood pressure exhibited an opposite pattern among the groups (all P<0.001). The sarcomere-length (SL), LV fibrotic area, cardiomyocyte size, and lung injury score were highest in group 4, lowest in groups 1 to 3 and significantly lower in group 6 than in group 5 (all P<0.0001). The protein expressions of fibrotic (Smad3/TGF-β), apoptotic (mitochondrial-Bax/cleaved-caspase3/PARP) and DNA-damaged (γ-H2AX) markers in lung and LV myocardium as well as oxidative (NOX-1/NOX2/oxidized protein) in LV myocardium exhibited an identical pattern of SL (all P<0.0001). The protein expressions of pressure/volume overload (BNP/MHC-β) mitochondrial-damaged (cytosolic cytochrome-C) of LV myocardium exhibited an identical pattern of SL (all P<0.001). In conclusion, Entresto is non-inferior to enalapril for protecting the heart-lung against CPS.
Keywords: Aortic constriction; apoptosis; cardiopulmonary syndrome; entresto; fibrosis; oxidative stress.