RESUMO
OBJECTIVE: To discuss the effect of Xiaoqinglong decoction on vascular endothelin (ET) in rats pulmonary hypertension (PAH) model based on the Jiebiaokuoluo method. METHODS: Sixty male SD rats were randomly divided into six groups: control group, PAH model group, positive drug group, and Xiaoqinglong decoction in the high-dose, medium-dose and low-dose groups, 10 rats in each group. The control group did not receive any treatment. The remaining groups were kept in low-pressure oxygen tanks, injections of lipopolysaccharide (LPS) at 200 µL on day 1 and day 14, respectively. The rats were smoked twice a day from day 2 to day 30 (except day 14) at 4 hours intervals. The rats were placed in a low-temperature environment for 1 hour per day, and were put into cold water to swim (for 2 weeks), while the rats were given a cold diet. After modeling, the control group and the PAH model group were given equal volumes of normal saline; the positive drug group was given bosentan (100 mg/kg); Xiaoqinglong decoction 15, 10 and 5 g/kg was given, respectively, in the high, medium and low dose groups; once daily for 30 days. The mean pulmonary artery pressure (mPAP) and right ventricle systolic pressure (RVSP) were then measured with right heart catheterization and the right ventricle hypertrophy index (RVHI) was assessed; ET-1 and nitric oxide (NO) levels were determined by radioimmunoassay. RESULTS: Compared with the control group, the levels of mPAP, RVSP, RVHI and ET-1 were significantly increased in the PAH model group [mPAP (mmHg, 1 mmHg ≈ 0.133 kPa): 33.20±1.04 vs. 13.20±1.03, RVSP (mmHg): 62.40±1.54 vs. 24.20±1.02, RVHI: 42.90±2.51 vs. 25.40±2.01, ET-1 (ng/L): 100.80±20.34 vs. 81.50±13.84, all P < 0.05], while NO levels were significantly decreased (mmol/L: 23.20±1.81 vs. 31.70±1.49, P < 0.05). Compared with the PAH model group, the levels of mPAP, RVSP, RVHI and ET-1 in the positive drug group and high, medium, low dose groups of Xiaoqinglong decoction were significantly decreased [mPAP (mmHg): 25.50±0.84, 26.90±0.74, 27.10±1.19, 29.10±0.75 vs. 33.20±1.04, RVSP (mmHg): 54.40±5.14, 50.10±1.67, 53.10±1.05, 56.60±1.07 vs. 62.40±1.54, RVHI: 41.10±1.19, 31.20±1.67, 31.30±1.89, 40.30±1.88 vs. 42.90±2.51, ET-1 (ng/L): 70.70±7.89, 69.90±2.92, 71.70±4.32, 73.90±5.19 vs. 100.80±20.34, all P < 0.05], while NO levels were significantly increased (mmol/L: 32.50±2.06, 34.70±1.16, 32.70±1.33, 30.10±1.19 vs. 23.20±1.81, all P < 0.05), and with the increased dose of Xiaoqinglong decoction, the change was more obvious, and the effect was better in the high-dose group. CONCLUSIONS: Xiaoqinglong decoction can reduce rats PAH by regulating ET-1 and NO levels in a dose-dependent manner.