Mechanism of action of L-arginine on the vitality of spermatozoa is primarily through increased biosynthesis of nitric oxide.

The ability of sperm to fertilize the egg is primarily dependent on sperm motility and membrane integrity. Nitric oxide (NO) plays a decisive role in regulating multiple functions within the male reproductive system. The aim of the present study is to determine the mechanism by which L-arginine confers a protective action on spermatozoa obtained from the goat epididymis. NO is synthesized from L-arginine by the enzyme nitric oxide-synthase (NOS) present in spermatozoa. A possible participation of NO and NOS in arginine action has been suggested.