*4.2. Amino Acids*

Asymmetric dimethylarginine (ADMA) is a L-arginine analogue produced in the cytoplasm in the process of protein modification. The formation of ADMA is dependent on oxidative stress status. ADMA is elevated by native or oxidized LDL and interferes with L-arginine in the production of nitric oxide (NO) [215]. Significantly higher ADMA concentrations were observed in serum and CSF of patients with RRMS and SPMS, while levels of arginine, L-homoarginine, nitrate, nitrite, ADMA did not differ between patients with MS and healthy controls [76] (Tables 3 and 4).
