Manipulating the natriuretic peptide system for the treatment of pulmonary hypertension
© Baliga et al; licensee BioMed Central Ltd. 2009
Published: 11 August 2009
We have recently reported that the combination of a neutral endopeptidase inhibitor (NEPI; prevents the breakdown of natriuretic peptides) and a phosphodiesterase 5 inhibitor (PDE5-I; prevents the hydrolysis of cyclic GMP), synergistically prevents pathogenesis in a hypoxia-induced model of pulmonary hypertension (PH; ). Herein, we have assessed the efficacy of this novel combination therapy to reverse disease severity in (a) established PH and (b) bleomycin-induced pulmonary fibrosis.
Methods and results
(a) Reversal of existing PH
In this study, the combination therapy (NEPI: ecadotril 60 mg/kg/day; PDE5I: sildenafil 30 mg/kg/day) was initiated after rats had been exposed to 3 weeks of chronic hypoxia (10% O2) to induce PH. This intervention resulted in a less pronounced elevation in right ventricular pressure (Control: 21.57 ± 3.432 mmHg, Hypoxia: 34.32 ± 3.882 mmHg, Hypoxia + combination therapy: 29.17 ± 1.965 mmHg) and reduced right ventricular hypertrophy (RV/LV+S ratio; Control: 0.2839 ± 0.01874, Hypoxia: 0.3411 ± 0.03317, Hypoxia + combination therapy: 0.3063 ± 0.01412) compared to untreated animals.
(b) Bleomycin-induced pulmonary fibrosis
These data demonstrate that the NEPI/PDE5I combination is effective in ameliorating disease severity in two models of PH with disparate aetiologies. First, the combination is valuable in reversing established (hypoxia-induced) PH and, second, the dual therapy is capable of reversing the pulmonary haemodynamic dysfunction in bleomycin-induced pulmonary fibrosis. Thus, this work substantiates the therapeutic potential of this novel combination therapy in PH.
- Baliga RS, Zhao L, Madhani M, Lopez-Torondel B, Visintin C, Selwood D, Wilkins MR, MacAllister RJ, Hobbs AJ: Synergy between natriuretic peptides and phosphodiesterase 5 inhibitors ameliorates pulmonary arterial hypertension. Am J Respir Crit Care Med. 2008, 178: 861-869. 10.1164/rccm.200801-121OC.PubMed CentralView ArticlePubMedGoogle Scholar
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