L-精氨酸对慢性间断性缺氧大白鼠肺循环和体循环的影响

EFFECTS OF L-ARGININE ON PULMONARY AND SYSTEMIC CIRCULATION IN CHRONIC INTERMITTENT HYPOXIC RATS

目的：本研究通过大鼠在慢性间断性缺氧状态下，持续给予L-精氨酸灌饲，动态观察其对大鼠肺循环和体循环的影响;方法：将大鼠随机分为三组：单纯缺氧组、缺氧给药组与正常对照组。用微导管插管分别测定各组大鼠的肺动脉与体循环的收缩压和舒张压;结果：单纯缺氧组与缺氧给药组的肺动脉压均高于正常对照组，除给药组第4周的肺动脉压外，均有显著性差异（P＜0.01、P＜0.05）。体循环压力各组间均无显著性差异（P＞0.05）。单纯缺氧组肺动脉压随缺氧时间延长而逐渐升高;缺氧给药组肺动脉压在第3周时明显下降，与单纯缺氧组比较有显著性差异（P＜0.01）;结论;内皮细胞是通过释放内皮衍生舒张因子（EDRF）而发挥调节肺血管张力的作用，机体急性缺氧时EDRF合成酶受到抑制，使内皮细胞EDRF释放减少，使肺血管收缩。L-精氨酸作为EDRF的合成前体，对缺氧性的肺血管收缩有一定抑制作用。给予L-精氨酸的补充，其作用的发挥有赖于内皮细胞结构和功能的完整。

The effect of L-arginine (Arg) on pulmonary and systemic circulation during chronic intermittent hypoxia in urethane anesthetized rats was studied. Methods: Experimental animals were diveded into three groups: single hypoxic, hypoxic added L-Arg by taken orally feed (10mg/kg,BW)and mormal control group. Simulated hypobaric hypoxia was at an altitude of 6000m for 8h per day for 4 weeks. The mean pulmonary artery pressure(Ppa)and systemic pressure by microcatheters. Results: Ppa were significantly increased both in single hypoxic and hypoxic+L-Arg groups compared with control group (P<0.01, P<0.05). However, the incrased degree of Ppa in L-Arg group was lowr than in the single group. There was no effect on systemic pressure. Conclusions: NO has been show to be an EDRF for pulmonary pressure,which is formed from L-Arg and is final common pathway for a variety of biological processes L-Arg as a prebiotic synthesis of EDRF could inhibited hypoxic pulmonary vasoconstriction in rats.