缺氧性肺动脉高压大鼠肺动脉一氧化氮合酶的实验研究

目的：研究大鼠肺动脉中一氧化氮合酶（ｎｉｔｒｉｃ ｏｘｉｄｅｓｙｎｔｈａｓｅ，ＮＯＳ）的含量及分布变化与慢性缺氧性肺动脉高压（ｈｙｐｏｘｉｃｐｕｌｍｏｎａｒｙ ｈｙｐｅｒｔｅｎｓｉｏｎ， ＨＰＨ）发生的关系。方法：采用ｅＮＯＳ多克隆抗体，对慢性ＨＰＨ 大鼠的肺组织进行免疫组织化学分析，观察缺氧组及对照组大鼠各级肺动脉中ｅＮＯＳ含量及定位；同时应用分光光度计测定缺氧组及对照组大鼠血浆中ＮＯ的间接浓度。结果：正常大鼠肺动脉内皮细胞及平滑肌细胞均含有较高的ｅＮＯＳ表达，且各级肺动脉中ｅＮＯＳ含量差异无显著性；缺氧组大鼠各级肺动脉内皮细胞及平滑肌细胞ｅＮＯＳ含量均较对照组显著减少；缺氧组大鼠血浆ＮＯ间接浓度较对照组明显降低。结论：大鼠肺动脉内皮细胞和平滑肌细胞ｅＮＯＳ含量下降及血浆ＮＯ浓度下降参与慢性ＨＰＨ 的形成。

A study on endothelial nitric oxide synthase in pulmonary arteries of hypoxic pulmonary hypertensive rats

Objective: To study the abundance and localization of nitric oxide synthase (NOS) in pulmonary arteries of rats and to explore the relationship between their changes and chronic hypoxic pulmonary hypertension (HPH). Methods: Immunohistochemistry technique was performed on the lung tissues of the HPH rats with eNOS multiclonal antibody to assay the abundance and localization of eNOS in different segments of pulmonary arteries of the hypoxic and control rats. At the same time, the plasma concentration of nitric oxide (NO) metabolite, nitrite, was measured by spectrophotometry. Results: eNOS expression was found in pulmonary artery endothelial cells and smooth muscle cells, and there was no significant difference among the different segments of pulmonary arteries, whereas the eNOS expression was inhibited in endothelial cells and smooth muscle cells of pulmonary arteries in hypoxia group; The plasma concentration of nitrite in hypoxia group was significantly decreased compared with that of control rats. Conclusion: The results suggest that the decrease in eNOS in pulmonary artery endothelial cells and smooth muscle cells by hypoxia as well as the decrease in plasma concentration of NO may play a role in the development of chronic HPH.