L-arginine and atherothrombosis

Area of Science:

• Cardiovascular Research
• Biochemistry
• Nutritional Science

Background:

• Endothelial dysfunction, characterized by reduced nitric oxide (NO) bioavailability, is a key feature of atherothrombosis.
• L-arginine is the primary substrate for endothelial nitric oxide synthase (eNOS), producing NO and L-citrulline.
• Supplementation with L-arginine has shown promise in improving endothelial function.

Purpose of the Study:

• To review the mechanisms by which L-arginine supplementation impacts endothelial nitric oxide (NO) bioactivity.
• To discuss the potential benefits and risks of L-arginine supplementation in the context of atherothrombosis.
• To explore the complex interrelationships between L-arginine, NO metabolism, and homocysteine pathways.

Main Methods:

• Literature review of studies investigating L-arginine's effects on endothelial function and NO production.
• Analysis of biochemical pathways involving L-arginine, nitric oxide synthase (NOS), and methyl group metabolism.
• Examination of clinical data on L-arginine supplementation in atherothrombotic conditions.

Main Results:

• L-arginine enhances NO production through increased uptake, competition with inhibitors (e.g., asymmetric dimethylarginine), antioxidant effects, histamine release, reduced norepinephrine activity, and stimulated insulin secretion.
• Potential adverse effects include increased homocysteine synthesis via S-adenosylhomocysteine, which can negatively impact endothelial function.
• Acute and chronic L-arginine administration can improve endothelial function in atherothrombosis.

Conclusions:

• L-arginine supplementation offers potential benefits for endothelial function in atherothrombosis by increasing NO bioavailability.
• The metabolic link between L-arginine and homocysteine presents a potential risk that requires careful consideration.
• Further research is needed to fully elucidate the benefits and risks of L-arginine supplementation for cardiovascular health.