Development of sensitve assay of NO and its clinical application

本研究旨在开发高灵敏度一氧化氮检测系统及其临床应用。我们新建立了鲁米诺化学发光法，并应用于大鼠离体灌注肾。使用该系统，我们发现内皮素-1通过刺激ETB受体释放NO，并且这种反应在内皮损伤的血管中减弱。肾上腺髓质素在NO-cGMP系统中表现出血管舒张作用，其第二信使仅被认为是cAMP。抗利尿激素通过V1受体增加NO释放。特别是，在动脉硬化血管中，一氧化氮可能极大地影响这些血管活性物质在调节血管张力中的作用。采用臭氧化学发光法对肝硬化肾功能衰竭患者呼出空气中NO的排泄量进行分析，发现NO的排泄量有所增加。此外，我们开发了一种对NO特异性敏感的荧光素，并成功地在培养细胞和组织切片中进行了NO的生物成像分析。我们还对心力衰竭患者尝试了NO吸入疗法。吸入一氧化氮使肺血管扩张，但没有改变全身血管系统，导致气体交换增加。此外，NO气体改善了这些患者的运动能力。这些结果提示吸入一氧化氮可能有助于改善心力衰竭患者的生活质量。

The aims of the present study were development of highly sensitive NO assay system and its clinical application. We newly developed luminol chemiluminescence assay for NO and applied it to the rat isolated perfused kidney. Using this system, we found that endothelin-1 released NO through stimulation of ETB receptors and that this response was attenuated in the vessels with endothelial damage. Adrenomedullin, of which second messenger had been believed only cAMP,exhibited vasodilatory action by NO-cGMP system. Vasopressin increased NO release through V1 receptors. In particular, in arteriosclerotic vessels, NO may greatly influence a role of these vasoactive substances in regulation of vascular tone. We analyzed NO output in the exhaled air of patients with liver cirrhosis and renal failure by ozone chemiluminescence, and found the increase in NO excretion. Furthermore, we developed a fluorescein specifically sensitive to NO,and succeeded in bioimaging analysis of NO in the cultured cells and tissue slices. We also tried an NO inhalation therapy in patients with heart failure. Inhaled NO dilated pulmonary vessels without changes in systemic vasculature, resulting in an increase in gas exchange. Moreover, NO gas improved exercise capacity in these patients. These results suggest that NO inhalation may be useful for improvement of quality of life in heart failure.