dimethylarginine and Vasculitis

The Cardiorenal Syndrome type 4 (CRS-4) defines a pathological condition in which a primary chronic kidney disease (CKD) leads to a chronic impairment of cardiac function. The pathophysiology of CRS-4 and the role of arterial stiffness remain only in part understood. Several uremic toxins, such as uric acid, phosphates, advanced glycation end-products, asymmetric dimethylarginine, and endothelin-1, are also vascular toxins. Their effect on the arterial wall may be direct or mediated by chronic inflammation and oxidative stress. Uremic toxins lead to endothelial dysfunction, intima-media thickening and arterial stiffening. In patients with CRS-4, the increased aortic stiffness results in an increase of cardiac workload and left ventricular hypertrophy whereas the loss of elasticity results in decreased coronary artery perfusion pressure during diastole and increased risk of myocardial infarction. Since the reduction of arterial stiffness is associated with an increased survival in patients with CKD, the understanding of the mechanisms that lead to arterial stiffening in patients with CRS4 may be useful to select potential approaches to improve their outcome. In this review we aim at discussing current understanding of the pathways that link uremic toxins, arterial stiffening and impaired cardiac function in patients with CRS-4.

Topics: Aorta; Arginine; Autonomic Nervous System Diseases; Bone Diseases, Metabolic; Cardio-Renal Syndrome; Cardiovascular Diseases; Chronic Disease; Endothelium, Vascular; Glycation End Products, Advanced; Humans; Inflammation; Myocardial Infarction; Oxidative Stress; Phosphorus; Renal Insufficiency, Chronic; Toxins, Biological; Tunica Intima; Uric Acid; Vascular Stiffness; Vasculitis

Continuous exposure to nitroglycerin (GTN) results in development of tolerance and is associated with increased free radical production and abnormal endothelial function. Elevated plasma biomarkers of inflammation have been shown to be associated with endothelial dysfunction in most cardiovascular conditions. It remains unclear whether exposure to GTN is also associated with increased biomarkers of endothelial and vascular injury or vascular inflammation. In an investigator-blind study, a total of 28 healthy volunteers were randomized to continuous therapy with GTN (0.6 mg/h 24 h/day for 7 days) or no therapy. Venous blood was collected on day 0 and day 7. Plasma levels of markers such as asymmetric dimethyl-arginine (ADMA), human soluble P-selectin, interleukin-6, tumor necrosis factor-alpha, intercellular adhesion molecule-1, and oxidized low-density lipoproteins were measured. The levels of blood markers on day 0 were similar in the control and GTN-treated groups. After 7 days of GTN exposure, there were no significant changes in the different markers of vascular inflammation and injury either in the GTN or control group (all p > 0.5). The present study documents that prolonged continuous therapy with transdermal GTN therapy is not associated with changes in markers of vascular inflammation and injury.

Topics: Administration, Cutaneous; Adolescent; Adult; Arginine; Biomarkers; Cell Adhesion Molecules; Dose-Response Relationship, Drug; Endothelium, Vascular; Humans; Interleukin-6; Lipoproteins, LDL; Male; Nitroglycerin; P-Selectin; Time Factors; Tumor Necrosis Factor-alpha; Vasculitis; Vasodilator Agents; Young Adult