L-arginine is a semi-essential amino acid that plays important roles in numerous physiological and pathological processes. This amino acid is called semi-essential because the body does not produce it in adequate amounts to meet the body's needs. L-arginine from exogenous sources is often necessary to ensure that l-arginine-involved processes are maintained. Some nutritional sources of l-arginine include peanuts, almonds, sunflower seeds, walnuts and hazelnuts. L-arginine is used for a variety of purposes, ranging from impotency to improvement in athletic performance. Most of its uses are based largely on the ability of l-arginine to improve blood flow to various organs.
Nitric Oxide
The vascular effects of l-arginine are mediated through nitric oxide. Nitric oxide is produced in the vascular endothelium from l-arginine by a chemical reaction catalyzed by nitric oxidase synthase. Endothelium is the layer of cells that line the inner walls of the blood vessels. Endothelium supports the smooth flowing of blood through the blood vessels. It is also a source of numerous chemical agents, such as nitric oxide, that affect vascular tone and reactivity.
Ischemic Stroke
L-arginine helps to maintain the integrity of the vascular endothelium. It also prevents platelet aggregation and platelet adhesion to the vascular endothelium. These effects prevent circulating blood from clotting. This is important because an injury to the endothelium can present a site for initiating blood clotting and developing atherosclerosis. If a blood clot forms in a blood vessel, the clot can dislodge and block a major blood vessel to the brain, leading to a stroke or to the lungs, leading to pulmonary embolism.
Angina Pectoris
L-arginine can relieve angina pectoris. Angina pectoris is chest pain that can result from ischemic heart disease. A common cause of ischemic heart disease is the occlusion of a branch of the coronary artery by fat and cholesterol deposits. L-arginine and other nitric oxide-releasing agents can dilate diseased coronary vessels and relieve angina pectoris by improving blood flow and oxygen delivery to the myocardium. Potent vasodilators, such as adenosine and nifedipine, are ineffective for relieving angina pectoris arising from diseased coronary vessels. These other vasodilators have selective effects on the resistant vessels, which are distal to the occlusion sites.
Peripheral Artery Disease
L-arginine can be used to alleviate the impairments and symptoms of peripheral artery disease, or PAD. PAD is a common problem that affects about 10 million Americans, according to MayoClinic.com. Similar to ischemic heart disease, peripheral artery disease is caused by cholesterol-containing fat deposits that form plaques in the walls of the blood vessels, referred to as atherosclerosis. The legs are often affected by PAD. Some of the symptoms include cramping or fatigue in the muscles of the hip, thigh, buttock and calf during activities such as walking. Coldness of the leg and foot is also common.
References
- "Circulation"; L-Arginine Induces Nitric Oxide--Dependent Vasodilation in Patients With Critical Limb Ischemia. A Randomized, Controlled Study; Stefanie M. Bode-Böger, et al. August 1996
- "American Journal of Hypertension"; Dietary L-Arginine Supplementation Normalizes Regional Blood Flow in Dahl-Iwai Salt-Sensitive Rats; H. He, et al.; May 1997
- MayoClinic.com: Peripheral Artery Disease (PAD)
Member Comments