Oxidative stress and endothelial function in chronic renal failure

This study aimed to investigate the relationship between oxidative stress a nd endothelium-dependent vasodilation in patients with chronic renal failur e (CRF). Thirty-seven patients with CRF underwent evaluation of endothelium -dependent vasodilation and endothelium-independent vasodilation by means o f forearm blood flow measurements with venous occlusion plethysmography dur ing local intra-arterial infusions of methacholine (evaluating endothelium- dependent vasodilation) and sodium nitroprusside (evaluating endothelium-in dependent vasodilation). Lag phase of lipoprotein fraction to oxidation, to tal antioxidative activity, diene conjugates, thiobarbituric acid reactive substances, lipid hydroperoxide, reduced glutathione (GSH), oxidized GSH (G SSG), and the GSH redox ratio (GSSG/GSH) were all measured as markers of ox idative stress. Two groups of healthy subjects (61 and 37 subjects, respect ively) were used as controls. In one group, oxidative stress markers were m easured, whereas endothelium-dependent vasodilation and endothelium-indepen dent vasodilation were assessed in the other group. Compared with controls, the patients with renal insufficiency had an impaired endothelium-dependen t vasodilation, a shorter lag phase of lipoprotein fraction, and higher lev els of diene conjugates, lipid hydroperoxide, and GSSG levels. The GSSG/GSH ratio was lower in patients with CRF. Endothelium-dependent vasodilation w as positively correlated with total antioxidative activity (r=0.41, P=0.016 ), GSH (r=0.44, P<0.0098), and lag phase of LDL (r=0.35, P=0.036) and negat ively correlated with GSSG (r=-0.40, P<0.018), GSSG/GSH (r=-0.47, P=0.0057) , and diene conjugates (r=-0.53 P<0.0015) in patients with CRF. These resul ts show that an impaired endothelium vasodilation function and oxidative st ress are related to each other in patients with CRF.