title: Combination of erythropoietin and sildenafil can effectively attenuate hypoxia-induced pulmonary hypertension in mice.
abstract: Pulmonary hypertension (PH) is an incurable disease that often leads to right ventricular hypertrophy and right heart failure. This study investigated single versus combined therapy with sildenafil and erythropoietin on hypoxia-induced pulmonary hypertension in mice. Mice were randomized into 5 groups and exposed to either hypoxia (10% oxygen) or normoxia for a total of 5 weeks. Hypoxic mice were treated with saline solution, erythropoietin (500 IU/kg 3 times weekly), sildenafil (10 mg/kg daily), or a combination of the two drugs for the last 2 weeks of hypoxic exposure. We measured right ventricular pressures using right heart catheterization, and the ventilatory response to hypoxia was recorded via whole-body plethysmography. Histological analyses were performed to elucidate changes in pulmonary morphology and appearance of right heart hypertrophy. Plasma levels of cardiotrophin-1 and atrial natriuretic peptide were quantified. Treatment with either erythropoietin or sildenafil alone lowered the hypoxia-induced increase of pulmonary pressure and reduced pulmonary edema formation, pulmonary vascular remodeling, and right ventricular hypertrophy. Notably, the combination of the two drugs had the most prominent effect. Changes in cardiotrophin-1 and atrial natriuretic protein levels confirmed these observations. The combination treatment with erythropoietin and sildenafil demonstrated an attenuation of the development of hypoxia-induced PH in mice that was superior to that observed for either drug when given alone.
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, Zurich, Switzerland ; Human Physiology Department, Medical School, Universidad Alas Peruanas, Lima, Peru.
authors.forename: Victor
authors.initials: V
authors.lastname: Samillan
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Haider
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, Zurich, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Vogel
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Leuenberger
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Division of Pulmonology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Brock
authors.affiliation: Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Colin
authors.initials: C
authors.lastname: Schwarzwald
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, Zurich, Switzerland ; Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: Max
authors.initials: M
authors.lastname: Gassmann
authors.affiliation: Institute for Veterinary Physiology, Vetsuisse Faculty, Zurich, Switzerland ; Zurich Center for Integrative Human Physiology, Zurich, Switzerland.
authors.forename: Louise
authors.initials: L
authors.lastname: Ostergaard
keywords: edema; pulmonary remodeling; right ventricular hypertrophy