Lowenstein C J, Dinerman J L, Snyder S H
Johns Hopkins University School of Medicine, Baltimore, Maryland.
Ann Intern Med. 1994 Feb 1;120(3):227-37. doi: 10.7326/0003-4819-120-3-199402010-00009.
To review the physiologic role of nitric oxide, an unusual messenger molecule that mediates blood vessel relaxation, neurotransmission, and pathogen suppression.
A MEDLINE search of articles published from 1987 to 1993 that addressed nitric oxide and the enzyme that synthesizes it, nitric oxide synthase.
Animal and human studies were selected from 3044 articles to analyze the clinical importance of nitric oxide. Descriptions of the structure and function of nitric oxide synthase were selected to show how nitric oxide acts as a biological messenger molecule.
Biochemical and physiologic studies were analyzed if the same results were found by three or more independent observers.
Two major classes of nitric oxide synthase enzymes produce nitric oxide. The constitutive isoforms found in endothelial cells and neurons release small amounts of nitric oxide for brief periods to signal adjacent cells, whereas the inducible isoform found in macrophages releases large amounts of nitric oxide continuously to eliminate bacteria and parasites. By diffusing into adjacent cells and binding to enzymes that contain iron, nitric oxide plays many important physiologic roles. It regulates blood pressure, transmits signals between neurons, and suppresses pathogens. Excess amounts, however, can damage host cells, causing neurotoxicity during strokes and causing the hypotension associated with sepsis.
Nitric oxide is a simple molecule with many physiologic roles in the cardiovascular, neurologic, and immune systems. Although the general principles of nitric oxide synthesis are known, further research is necessary to determine what role it plays in causing disease.
综述一氧化氮这一特殊信使分子的生理作用，它介导血管舒张、神经传递及病原体抑制。
对1987年至1993年发表的关于一氧化氮及其合成酶一氧化氮合酶的文章进行医学文献数据库检索。
从3044篇文章中选取动物和人体研究以分析一氧化氮的临床重要性。选取一氧化氮合酶结构与功能的描述以展示一氧化氮如何作为生物信使分子发挥作用。
若三项或更多独立观察者得到相同结果，则对生化和生理研究进行分析。
两类主要的一氧化氮合酶产生一氧化氮。在内皮细胞和神经元中发现的组成型同工酶短暂释放少量一氧化氮以向相邻细胞发出信号，而在巨噬细胞中发现的诱导型同工酶持续释放大量一氧化氮以清除细菌和寄生虫。通过扩散到相邻细胞并与含铁的酶结合，一氧化氮发挥许多重要的生理作用。它调节血压，在神经元之间传递信号，并抑制病原体。然而，过量的一氧化氮会损害宿主细胞，在中风期间导致神经毒性，并导致与脓毒症相关的低血压。
一氧化氮是一种简单分子，在心血管、神经和免疫系统中具有多种生理作用。尽管一氧化氮合成的一般原理已为人所知，但仍需进一步研究以确定其在致病过程中所起的作用。
