OBJECTIVETo investigate the effects of rosuvastatin on monocrotaline (MCT)-induced pulmonary artery hypertension in rats.

METHODSPulmonary arterial hypertension was induced by a single subcutaneous injection of monocrotaline (50 mg/kg) in rats. In the prevention protocol, 32 male Sprague-Dawley rats were randomly divided into four groups (n = 8 each): low-dose rosuvastatin prevention group (2 mg×kg(-1)×d(-1)), high-dose rosuvastatin prevention group (10 mg×kg(-1)×d(-1)), pulmonary arterial hypertension group, normal control group. Beginning on the MCT injection day, rats were treated with rosuvastatin by daily gavage for 4 weeks. Normal control group and pulmonary arterial hypertension group received vehicle by gavage. In the treatment protocol, 52 male Sprague-Dawley rats were randomly divided into four groups (n = 13 each): low-dose rosuvastatin treatment group (2 mg×kg(-1)×d(-1)), high-dose rosuvastatin treatment group (10 mg×kg(-1)×d(-1)), pulmonary arterial hypertension group, normal control group. Four weeks after MCT injection, rats were treated with rosuvastatin by daily gavage for 4 weeks. Normal control group and pulmonary arterial hypertension group received vehicle by gavage. At the end of study, survival rates, mean pulmonary arterial pressure (mPAP), wall thickness of small pulmonary artery and right ventricular hypertrophy among groups were compared. The expression levels of proliferating cell nuclear antigen (PCNA) and endothelial nitricoxide synthase (eNOS) protein in small pulmonary artery, the expression levels of Rho kinase 1(ROCK-1) and eNOS mRNA in lung tissue were also detected.

RESULTSAll rats in the prevention protocol survived. Rosuvastatin treatment improved survival in the treatment protocol (58%, 75% vs.30%, P < 0.05). Rosuvastatin therapy in both preventive or treatment protocols significantly lowered mPAP [prevention protocol: (27.53 ± 3.43), (25.72 ± 1.76) vs. (36.05 ± 2.45) mm Hg (1 mm Hg = 0.133 kPa), P < 0.01; treatment protocol: (30.39 ± 3.17), (27.59 ± 1.99) vs. (40.68 ± 1.39) mm Hg, P < 0.01], reduced thickening of small pulmonary artery wall (P < 0.01) and right ventricular hypertrophy (P < 0.01). Rosuvastatin also inhibited PCNA expression of SMC (P < 0.01), restored eNOS expression of EC (P < 0.05) and inhibited ROCK-1 mRNA expressions in lung tissue (P < 0.05).

CONCLUSIONSRosuvastatin therapy reduced mPAP in monocrotaline-induced pulmonary arterial hypertension rat model and this effect is linked with inhibition of ROCK-1 expression, inhibition of smooth muscle cell proliferation and restoration of endothelial cell functions.