N~ω─硝基─L─精氨酸对兔慢性缺氧心肌区域血流量的影响

Effects of N ω nitro L arginine on regional myocardial blood flow in chronic intermittent hypoxia in rabbits

观察了一氧化氮（ＮＯ）合成酶抑制剂Ｎω－硝基－Ｌ－精氨酸（Ｌ－ＮＮＡ）对慢性缺氧兔心肌区域血流量的影响。结果表明，慢性缺氧兔的动脉血红细胞压积明显增高；心肌区域血流量无明显变化。静脉输入Ｌ－ＮＮＡ后，右室内、外层心肌区域血流量均明显降低，左室仅外层血流量降低，其余两层无明显变化。说明ＮＯ参与慢性缺氧兔心肌血管基础张力调节。

The effects of N ω nitro L arginine (L NNA) on the regional myocardial blood flow (MBF) were observed in rabbits after the animals were exposed to intermittent hypoxia in a hypobaric chamber for 29±1 d. It was found that intermittent chronic hypoxia resulted in an increase of arterial hematocrit but no significant change of MBF was shown. After intravenous infusion of L NNA, MBF of the inner and outer layers of the right ventricle was significantly reduced and that of the outer layer of the left ventricle was reduced without the involvement of its middle and inner layers. These findings suggest that NO takes part in the modulation of coronary vascular tone in chronic hypoxia in rabbits.