Asymmetric Dimethylarginine: Clinical Significance and Novel Therapeutic Approaches.

Asymmetric dimethylarginine (ADMA) is a competitive endogenous inhibitor of nitric oxide synthase with a key role in the pathophysiology of endothelial dysfunction, in the progression of atherosclerosis and in cardiovascular diseases. Statins, renin-angiotensin-aldosterone system inhibitors, blood glucose lowering agents, insulin sensitizers, beta-blockers, estrogen replacement therapy, antioxidants, complex B vitamins, L-arginine and acetylsalicylic acid have been evaluated for their ability to reduce ADMA levels or inhibit its actions. Despite the major beneficial effects of these agents in cardiovascular disease, research has shown that their favorable actions are only partially mediated by reducing ADMA levels or by bypassing its effect in nitric oxide synthesis. Novel therapeutic approaches targeting selectively ADMA are encouraging, but have only been tested in vitro or in animal studies and further research is needed in order to conclude on how therapeutic strategies modulating ADMA actions can affect atherosclerosis progression and cardiovascular diseases.