title: Bosentan, sildenafil, and their combination in the monocrotaline model of pulmonary hypertension in rats.
abstract: The dual endothelin receptor antagonist, bosentan, and the phosphodiesterase inhibitor, sildenafil, are efficacious in experimental and clinical pulmonary hypertension (PHT). The effects of bosentan, sildenafil, and their combination were evaluated in rats with monocrotaline (MCT)-induced PHT. A first group consisted of control rats with no MCT injection. Four other groups of rats received MCT subcutaneously and were assigned to receive no treatment, 300 mg/kg/day bosentan as food admix, 100 mg/kg/day sildenafil in drinking water, or their combination for 4 weeks. The doses of bosentan and sildenafil were the maximally effective doses based on a dose-range-finding study. Mortality was 0%, 53%, 11%, 11%, and 0%, respectively, in the five different groups. Bosentan and sildenafil significantly attenuated the increase in mean pulmonary arterial pressure, and the combination had an additional effect. Similarly, bosentan, sildenafil, and, to a greater extent, their combination significantly reduced right ventricular (RV) hypertrophy. Bosentan, but not sildenafil, decreased norepinephrine and BNP plasma concentrations, reduced kidney weight, and normalized systemic hemodynamics. In conclusion, bosentan and sildenafil are efficacious in rats with chronic PHT, and their combination shows an additional effect for decreasing pulmonary arterial pressure, reducing plasma catecholamines, maintaining body weight, and reducing mortality.
authors.affiliation: Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland. martine.clozel@actelion.com
authors.forename: Martine
authors.initials: M
authors.lastname: Clozel
authors.forename: Patrick
authors.initials: P
authors.lastname: Hess
authors.forename: Markus
authors.initials: M
authors.lastname: Rey
authors.forename: Marc
authors.initials: M
authors.lastname: Iglarz
authors.forename: Christoph
authors.initials: C
authors.lastname: Binkert
authors.forename: Changbin
authors.initials: C
authors.lastname: Qiu
mesh_terms: D000818:Animals; D000077300:Bosentan; D004195:Disease Models, Animal; D004359:Drug Therapy, Combination; D065128:Endothelin Receptor Antagonists; D006976:Hypertension, Pulmonary / Q000139:chemically induced / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D016686:Monocrotaline / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D011687:Purines; D051381:Rats; D017208:Rats, Wistar; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000494:pharmacology* / Q000627:therapeutic use; D013450:Sulfones
chemical_list: D065128:Endothelin Receptor Antagonists; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D013450:Sulfones; D016686:Monocrotaline; D000068677:Sildenafil Citrate; D000077300:Bosentan