Nitric oxide(NO) is a gas of small molecule with toxic properties, but it is also a biologically active substance involved in numerous pathologic and physiologic processes. NO is produced in vivo from L arginine by nitric oxide synthase. It can be found in testis, epididymis, vas deferens and in the acrosome and tail of spermatozoa. Nitric oxide has been shown to play significant roles and biphasic effects in all stages of spermatogenesis, sperm motility, viability, and fertilization as well as lipid ...