一氧化氮(NO)是由L-精氨酸通过一氧化氮合成酶(NOS)的催化而合成。在血管系统,内皮细胞上存在的原生NOS所合成的NO对人和动物具有扩张血管的作用;在免疫系统,巨噬细胞和白细胞上存在的诱生NOS受细菌内毒素或某些细胞因子的激活而合成的NO具有细胞毒性。本文述及NO的生物化学、病理生理及其测定方法。 Nitric oxide (NO) is synthesized by the reaction of L-arginine with nitric oxide synthase (NOS). NO, synthesized by native NOS present on the vascular system, endothelial cells, has the effect of dilating blood vessels in humans and animals; the induction of NOS on the immune system, macrophages and leukocytes is affected by bacterial endotoxins or certain cytokines The activated and synthesized NO is cytotoxic. This article describes the biochemistry, pathophysiology and determination of NO.