The amino acid arginine and one of its metabolites NO have gathered broad attention in the last decade. Although arginine is regarded as a conditionally essential amino acid in disease, L-arginine supplementation in severe illness has not found its way into clinical practice. This might be due to the invalid interpretation of results from studies with immune-enhancing diets containing L-arginin...

Low renal nitric oxide (NO) bioavailability contributes to the development and maintenance of chronic hypertension. We investigated whether impaired l-arginine transport contributes to low renal NO bioavailability in hypertension. Responses of renal medullary perfusion and NO concentration to renal arterial infusions of the l-arginine transport inhibitor l-lysine (10 μmol·kg(-1)·min(-1); 30 min...

OBJECTIVE L-arginine serves as a substrate for the formation of NO by the NO synthase (NOS) enzymes. In some studies, dietary supplementation of L-arginine reduces atherosclerosis through the restoration of NO release and improvement in endothelial function. In the present study, we investigate the effect of L-arginine supplementation on the development of atherosclerosis in a mouse model. ME...

The metabolism of the amino acid L-arginine is emerging as a crucial mechanism for the regulation of immune responses. Here, we characterized the impact of L-arginine deprivation on T cell and macrophage (MPhi) effector functions: We show that whereas L-arginine is required unconditionally for T cell activation, MPhi can up-regulate activation markers and produce cytokines and chemokines in the...

Acute inflammation impairs vascular function. Based on the association between endothelial dysfunction and plasma concentrations of L-arginine and the endogenous nitric oxide synthase inhibitor ADMA (asymmetrical dimethylarginine), we hypothesized that the ratio between L-arginine and ADMA could be affected by experimental inflammation. Plasma concentrations of L-arginine, ADMA and SDMA (symmet...

OBJECTIVE To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vaso...

The effects of twice-daily injections of L-arginine or D-arginine (200 mg/kg i.p.) for 4 days on morphine-induced antinociception, brain nitric oxide synthase activity and brain and serum distribution of morphine and brain mu-opioid receptors labeled with [3H][D-Ala2,MePhe4,Gly5-ol]enkephalin were determined in male Swiss-Webster mice. Chronic treatment with L-arginine, but not D-arginine, decr...