V-004 COMBINATION EFFECTS OF TADALAFIL AND CITRULLINE TO PREVENT WORSENING MONOCROTALINE–INDUCED PULMONARY HYPERTENSION IN RATS

Abstract

Background Tadalafil, phosphodiesterase5 (PDE5) inhibitor, was reported to have a therapeutic effect on pulmonary hypertension (PH) and citrulline is an amino acid to dilate arteries as a mild NO donor. Combination effects of tadalafil and citrulline has been unknown. The aim of this study is to evaluate the combination effects of tadalafil and citrulline on monocrotaline (MCT) -induced PH in rats. Methods We used 4-week-old male SD rats which developed PH from about 7-week old by 5-times subcutaneous injection of MCT. We evaluated heart function by echocardiography before and after 6 times administration per two weeks of saline, tadalafil alone, citrullin alone and tadalafil and citrullin. Results The survival rate of tadalafil and citrullin administration was 91.7%, which was higher than other groups (a tadalafil alone: 58.3%, a citrullin alone: 50%, a saline: 33.3%). The ratios of right to left ventricular end-diastolic area in a tadalafil alone, a citrullin alone and a tadalafil and citrullin group were significantly lower than those in a saline group (1.97+0.60, 2.10 + 1.17, 2.02 + 0.93 vs 3.07 + 0.76). However, those ratios among three groups were almost same. Conclusion Combination therapy of tadalafil and citrullinecould be useful to prevent deterioration of PH.