The Endothelial ADMA/NO Pathway in Hypoxia-Related Chronic Respiratory Diseases

Figure 1

Endothelial L-arginine/NO pathway. L-arginine residues in proteins are methylated by protein-arginine methyltransferases (PRMT), after proteolysis ADMA is released and could replace L-arginine from the binding site at the NOS. ADMA is mainly degraded by dimethylarginine dimethylaminohydrolases (DDAH) to L-citrulline. The degradation of ADMA by alanine-glyoxylate aminotransferase 2 (AGXT-2) to 𝛼-keto-𝛿-(N(G),N(G)-dimethylguanidino)valeric acid (DMGV) is described as an alternative way which metabolized ADMA only to a very small proportion. This ADMA/AGXT-2 pathway is not object of this review.