Sacubitril/valsartan treatment relieved the progression of established pulmonary hypertension in rat model and its mechanism

Abstract Aims Pulmonary hypertension (PH) is a fatal disease identified by progressive elevated pulmonary arterial pressure, which neurohormonal activation is a notable contributor to its development. Sacubitril/valsartan is a complex of sacubitril [via enhancing the natriuretic peptide (NP) system] and valsartan [via blocking the renin-angiotensin-aldosterone system (RAAS)]. Regulation of the two neurohormonal system had been shown to attenuate PH. This study was to explore the role of sacubitril/valsartan in both monocrotaline (MCT)-induced and hypoxia-induced rat models and the underlying mechanism. Main methods The rats were treated with MCT or hypoxic environment for 14 days, after that sacubitril/valsartan were given for another 14 days. Hemodynamic measurements and histological assessments were performed. The expression of NPs was measured using RT-PCR and ELISA, while the protein level of natriuretic peptide receptors (NPRs) and AT1 receptor were detected by western blot, the concentrations of cGMP, IL-1β, IL-6, TNF-α and TGF-β1 were tested by ELISA. Key findings We found that sacubitril/valsartan significantly improved the hemodynamic and histological data of two PH models. Sacubitril/valsartan suppressed the protein expression of AT1 receptor (P  Significance Sacubitril/valsartan alleviated PH in MCT-induced and hypoxia-induced rat models by inhibiting the activated RAAS, promoting ANP/NPR-A/cGMP and CNP/NPR-B/cGMP pathway, restoring the NPR-C signaling and the anti-inflammatory effects.