〔Abstract〕 Objective: To compare the characteristics of three methods: monocrotaline (MCT), hypobaric hypoxia (HPH), and SU5416 combined with hypobaric hypoxia (SuHx) in constructing pulmonary arterial hypertension (PH) rat models. Methods: Male SD rats were randomly divided into a control group and three experimental groups: MCT group, HPH group, and SuHx group. The MCT group received intraperitoneal injection of MCT 50 mg/kg and was routinely raised for 4 weeks. The HPH group was placed in a low pressure oxygen chamber at an altitude of 5 000 meters for 8 weeks, and the SuHx group received subcutaneous injection of SU5416 20 mg/kg and placed in a low-pressure oxygen chamber at an altitude of 5 000 meters for 3 weeks. After the model being made, the pulmonary artery pressure, right ventricular pressure, left ventricular function and blood cell count of rats in each group were measured, heart coefficient and the right heart hypertrophy index of rats were calculated
, and the pathological changes of lung tissue were observed. Results: Compared with the control group, the pulmonary artery pressure, right ventricular pressure and right ventricular hypertrophy index of the experimental group rats increased, and the right ventricular pressure of the SuHx group increased more significantly than the other two experimental groups, the difference was statistically significant(P<0.05); The left ventricular diastolic function decreased, red blood cells and hemoglobin increased, and platelets decreased in the HPH and SuHx groups; However, in the MCT group, there was an increase in platelets, with little change in red blood cells and platelets; Compared with the control group, the pulmonary artery wall thickness of the experimental group significantly increased, the difference is statistically significant (P<0.05). Conclusion: Three methods can be used to construct a rat model of pulmonary hypertension, and SuHx has the best modeling effect.