Simplified schematic of the L-arginine/NO pathway along with key analytical references. Enzymatic components are shown as a black box with white text. NO metabolic references are indicated by gray background boxes. Abbreviations are: ASL, arginine succinat lyase; DDAH, dimethylarginine dimethylaminohydrolase; NRA, nitrite reductase activity; CC, citrate cycle; UC, urea cycle; 3-NtY, 3-nitrotyrosine; N-ntW, N-nitrosotryptophan; ADMA, asymmetric dimethylarginine; RSNO, S-nitrosothiols; PRMT, protein-arginine methyltransferase.