Search results for "Xanthine"
showing 9 items of 139 documents
Poly-ADP ribose polymerase, xanthine oxidase and nitric oxide synthase expression in kidney tissue of experimental diabetes
2014
Background The spatial distribution of inflammatory and DNA reparation markers in the kidney tissue in diabetes is poorly understood. Aim The present study investigated the role of endothelial and inducible nitric oxide synthase (eNOS and iNOS), Poly ADP ribose polymerase (PARP) xanthine oxidase (XO) in the pathogenesis of streptozotocin-induced diabetic changes in the kidney tissue. Methods Diabetes mellitus was induced in rats by a single injection of streptozotocin (STZ) at a dose of 50 mg/kg. The XO, PARP, eNOS and iNOS protein expression in the kidney was studied by immunohistochemistry. Results Obtained results showed that STZ administration incresed the numbers of PARP and XO-positiv…
Endotheliale Dysfunktion: Pathophysiologie, Diagnostik und prognostische Bedeutung
2008
The endothelium plays a crucial role in the regulation of vascular tone. Recent studies have indicated that endothelial dysfunction develops in the presence of cardiovascular risk factors such as hypertension, diabetes mellitus, hypercholesterolemia and in chronic smokers, as well as in patients with a family history of cardiovascular disease. It has now been established that endothelial dysfunction represents the first indicator of vascular damage. Endothelial function can be assessed in coronary and peripheral conductance and resistance vessels by means of invasive and noninvasive (ultrasound-guided) methods such as intracoronary infusion of acetylcholine, the endothelium-dependent vasodi…
Xanthine Oxidase Is Involved in Free Radical Production in Type 1 Diabetes
2002
The aim of this work was to study the mechanism of free radical formation in type 1 diabetes and its possible prevention. We have found oxidation of blood glutathione and an increase in plasma lipoperoxide levels in both human type 1 diabetes and experimental diabetes. Peroxide production by mitochondria does not increase in diabetes. On the contrary, the activity of xanthine oxidase, a superoxide-generating enzyme, increases in liver and plasma of diabetic animals. The increase in plasma xanthine oxidase activity may be explained by the increase in the hepatic release of this enzyme, which is not due to nonspecific membrane damage: release of other hepatic enzymes, such as the amino transf…
Is oxidative stress a therapeutic target in cardiovascular disease?
2010
An abnormal production of reactive oxygen species (ROS) and the subsequent decrease in vascular bioavailability of nitric oxide (NO) have long been proposed to be the common pathogenetic mechanism of the endothelial dysfunction, resulting from diverse cardiovascular risk factors such as hypercholesterolaemia, diabetes mellitus, chronic smoking, metabolic syndrome, and hypertension. Superoxide produced by the nicotinamide dinucleotide phosphate (NADPH) oxidase, mitochondrial sources, or the xanthine oxidase may react with NO, thereby resulting in excessive formation of peroxynitrite, a reactive nitrogen species that has been demonstrated to accelerate the atherosclerotic process by causing d…
Oxidative Stress and Ubiquitin Ligases: their involvement in skeletal muscle atrophy
2015
Introduction Muscle atrophy plays a relevant role in the many very prevalent diseases. Generation of reactive oxygen species (mainly by the xanthine oxidase) and inflammation are two of the main triggers of muscle atrophy. Aim The major aim of our study was to determine the mechanism by which reactive oxygen species activate E3 ubiquitin ligases (MuRF-1 and MAFbx) cause muscle atrophy. Possible prevention by allopurinol, a well-known xanthine oxidase inhibitor widely used in clinical practice; and by indomethacin, a non-steroidal antiinflamatory drug was also studied. Materials and methods Male C57BL/6J mice (3 months old) conditioned by 14 days of hindlimb unloading with or without each tr…
Inhibition of xanthine oxidase to prevent statin-induced myalgia and rhabdomiolysis
2015
Although statins remain the cornerstone of lipid-lowering therapy for reducing the burden of atherosclerotic vascular disease, their administration has been associated with muscle-related adverse effects, including myalgia and rhabdomyolysis. Such adverse events are probably due to reduced antioxidant defenses associated with fewer intermediate metabolites in the cholesterol synthesis pathway. We hypothesize that the concomitant inhibition of xanthine oxidase via coadministration of allopurinol with statins could diminish reactive oxygen species (ROS)-related muscle damage, which would have in turn have positive effects on both the incidence of muscle-related adverse events and cardiovascul…
Low levels of both xanthine dehydrogenase and of cellular retinol binding protein are responsible for retinoic acid deficiency in malignant human mam…
2009
The seeming impairment of retinoid metabolism in human breast tumor cells has been attributed to the lower expression of cellular retinol binding proteins (CRBPs), of alcohol/retinol dehydrogenases, or aldehyde/retinaldehyde dehydrogenases. In a previous study we indicated that xanthine dehydrogenase (XDH) is able to oxidize actively both all-trans-retinol (t-ROL) bound to the CRBP (holo-CRBP) and all-trans-retinaldehyde (t-RAL) to all-trans-retinoic acid (t-RA) in human mammary epithelial cells (HMEC). Since both XDH and CRBP are required for the biosynthesis of t-RA, we have inspected their bioavailability in both estrogen-responsive and nonresponsive human mammary epithelial cancer cells…