Fasudil reverses monocrotaline-induced pulmonary hypertension in rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the effects and related mechanisms of fasudil on monocrotaline-induced pulmonary arterial hypertension (PAH) in rats.</p><p><b>METHODS</b>A total of 56 healthy male Sprague-Dawley rats were randomly divided into 5 groups: 4 weeks control group (N4), 4 weeks PAH group (M4), 8 weeks control group (N8), 8 weeks PAH group (M8), 8 weeks PAH and fasudil group (F8). PAH was induced by subcutaneous injection of monocrotaline (50 mg/kg). Animals in F8 group received intraperitoneal injection of fasudil hydrochloride (15 mg×kg(-1)×d(-1)) from the end of the 4th week to the end of the 8th week. Rats in control groups and PAH groups received equal volume saline injection. Polyethylene catheters were inserted into the RV through the jugular vein for right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) measurements after various treatment protocols. RV hypertrophy index [RV/(LV+S)] was also measured. Arteries of 50 to 150 µm were evaluated for the median wall thickness and wall area by HE staining as follows: percent wall thickness (WT%) = [(medial thickness×2/external diameter)]×100 and percent wall area (WA%) = (wall area/total area)×100%. The mRNA expression of ROCK-1 in lung tissue was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The protein expressions of ROCK-1 and MYPT-1 in lung tissue were analyzed by Western blot and MYPT-1 phosphorylation, respectively.</p><p><b>RESULTS</b>Forty-one rats survived and mortality rate was zero in N4, N8 and M4 groups. Survival rate was significantly higher in F8 group compared to M8 group (75.00% vs. 31.25%, P < 0.05). At the end of the 4th week, RVSP [(62.25 ± 3.24) vs. (31.33 ± 2.35) mm Hg(1 mm Hg = 0.133 kPa)], mPAP [(36.38 ± 2.31) vs.(20.32 ± 1.81) mm Hg], [RV/(LV+S)] (0.5648 ± 0.0580 vs. 0.3458 ± 0.0455), WT% [(25.63 ± 5.35)% vs.(13.38 ± 3.45)%], WA% [(60.36 ± 2.51)% vs. (38.42 ± 2.84)%] were all significantly higher in M4 group than in N4 group (all P < 0.01). RVSP [(54.64 ± 4.11) vs. (67.37 ± 4.68) mm Hg], mPAP [(26.25 ± 2.32) vs. (39.83 ± 1.83) mm Hg], and markedly relieve [RV/(LV+S)] (0.3985 ± 0.0210 vs. 0.7600 ± 0.0341), WT% [(15.64 ± 2.81)% vs. (28.26 ± 4.38)%], WA% [(40.35 ± 2.82)% vs. (68.83 ± 1.63)%] were all significantly lower in F8 group than in M8 group (all P < 0.05) while the expression of ROCK-1 mRNA (1.2139 ± 0.1778 vs. 1.6839 ± 0.3251, P < 0.01), and the protein expression of ROCK-1 and MYPT-1 as well as the extent of MYPT-1 phosphorylation were all downregualted in F8 group compared to M8 group (all P < 0.01).</p><p><b>CONCLUSIONS</b>Fasudil can effectively reverse the MCT-induced PAH in rats via downregulating ROCK-1 and MYPT-1.</p>

Effects of rosuvastatin on monocrotaline-induced pulmonary artery hypertension in rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of rosuvastatin on monocrotaline (MCT)-induced pulmonary artery hypertension in rats.</p><p><b>METHODS</b>Pulmonary 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.</p><p><b>RESULTS</b>All 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).</p><p><b>CONCLUSIONS</b>Rosuvastatin 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.</p>