一氧化氮 (NO)是一种具有双重作用的体内局部调节因子 ,由L_精氨酸在一氧化氮合酶 (NOS)的作用下生成。最近研究表明 ,NO及NOS在雄性生殖系统分布广泛 ,NOS主要分布于睾丸间质细胞、支持细胞 ,少量分布于生精细胞。NO能够调节睾丸的血液供应、激素的分泌和雄性的生殖能力。高浓度NO能够扩张睾丸血管、损害生精功能和抑制精子的活力 ,从而使男性生育能力低下 ,严重时导致男性不育症。本文简要介绍NO及NOS的检测方法、性质与分类 ,并着重讨论NOS的分布及NO对雄性生殖能力的调节作用 Nitric oxide (NO) is a dual, in vivo, local regulator that is produced by L-arginine under the action of nitric oxide synthase (NOS). Recent studies have shown that NO and NOS are widely distributed in the male reproductive system. NOS is mainly distributed in the testicular stromal cells, supporting cells, a small amount of distribution in spermatogenic cells. NO regulates testicular blood supply, hormone secretion and male reproductive capacity. High concentrations of NO can dilate testicular blood vessels, impair the function of spermatogenesis and inhibit the vitality of spermatozoa, resulting in poor fertility in males and male infertility in severe cases. This article briefly describes the detection methods, nature and classification of NO and NOS, and focuses on the distribution of NOS and the regulatory effect of NO on male reproductive capacity