The role of DDAH is to break down modified amino acids (Asymmetric dimethylarginine (ADMA) and monomethyl arginine (L-NMMA)) that are produced by the body and hae been shown to inhibit NO synthase.

• DDAH的作用是破坏由体内产生的被修饰的氨基酸（不对称的二甲基精氨酸(ADMA)和一甲基精氨酸(L-NMMA)）并已证实它可以抑制NO的合成。