Asymmetric dimethylarginine–Nitric oxide synthase pathway (ADMA–NOS pathway)

The Asymmetric dimethylarginine–Nitric oxide synthase (ADMA–NOS) pathway is a biochemical regulatory system centered on the endogenous inhibition of nitric oxide synthase (NOS) by asymmetric dimethylarginine (ADMA) (Sibal et al., 2010, PubMed). ADMA is produced through the methylation of arginine residues in proteins by protein arginine methyltransferases (PRMTs) and is subsequently released during protein degradation (Leiper and Nandi, 2011, PubMed). It acts as a competitive inhibitor of all three NOS isoforms, thereby reducing the production of nitric oxide (NO), a key mediator of vasodilation and vascular homeostasis (Tain and Huang, 2014, PubMed). The primary route for ADMA clearance is enzymatic degradation by dimethylarginine dimethylaminohydrolase (DDAH), making DDAH a central regulator of NO bioavailability (UniProt O94760). Elevated levels of ADMA are recognized as a significant biomarker for endothelial dysfunction and are linked to various pathologies, including atherosclerosis, hypertension, and chronic kidney disease (Sibal et al., 2010, PubMed). Pharmacological modulation of this pathway aims to restore NO levels, either by supplementing the substrate L-arginine or by enhancing DDAH activity to lower ADMA concentrations (Leiper and Nandi, 2011, PubMed). Several existing drugs, such as statins and certain angiotensin II receptor blockers, have been shown to indirectly influence this pathway by lowering ADMA levels (Tain and Huang, 2014, PubMed). Targeting the ADMA–NOS axis represents a promising therapeutic approach for treating cardiovascular and metabolic conditions characterized by impaired vascular reactivity.

Other names

ADMA/DDAH/NOS axisArginine-ADMA-NO pathwayDimethylarginine-Nitric Oxide pathway

Competitive inhibition of Nitric oxide synthase (NOS) by ADMA; modulation of ADMA levels via Dimethylarginine dimethylaminohydrolase (DDAH) activity or Protein arginine methyltransferase (PRMT) expression (Leiper and Nandi, 2011, PubMed).