The effect of L-arginine on high pulmonary blood flow-induced pulmonary hypertension

Objective To explore the therapeutic effect of L-arginine on high pulmonary blood flow-induced pulmonary hypertension.Methods 21 male SD rats were randomly divided into shunting group, shunting with L-arginine group, and control group. Abdominal aorta and inferior vena cava shunting were produced in rats of shunting group and shunting with L-arginine group. After 11-week shunting, pulmonary artery mean pressure ( mPAP ) of each rat was evaluated by using a right cardiac catheterization procedure. The ratio of right ventricular mass to body weight (RV/BW) and the ratio of right ventricular mass to left ventricular plus septal mass (RV/LV+S) were detected. Pulmonary vascular microstructure was measured.Results mPAP, RV/BW and RV/LV+S were significantly increased in shunt rats as compared with those of normal controls(P0.01, respectively). Muscularization of small pulmonary artery and relative medial thickness and relative medial area of pulmonary muscularized arteries were obviously increased in shunt rats compared with controls. However, mPAP, RV/BW and RV/LV+S were significantly decreased in rats of shunting with L-arginine group as compared with shunt rats (P0.05, respectively).L-arginine ameliorated pulmonary vascular structural remode-ling.Conclusion L-arginine plays an important role in regulation of the development of high pulmonary blood flow-induced pulmonary vascular remodeling and pulmonary hypertension.