XOR - Possible Correlations with Oxidative Stress and Inflammation Markers in the Context of Diabetic Kidney Disease

Abstract

Xanthine oxidoreductase (XOR) activity plays an important role as a pivotal source of reactive oxygen species. The aim of our study was to investigate possible correlations of XOR serum levels with oxidative stress (total antioxidant capacity - TAC, anti-oxidative stress responsive 1 antibody - OXSR1) and inflammation markers (interleukin 6 - IL-6), in 20 hemodialysis diabetic patients. The present study included the hemodialysis diabetic patients group (10 males and 10 females) and the control group (20 healthy volunteers). For serum XOR (ng/mL), TAC (U/mL) and OXSR1 (ng/ml) measurements we have used the ELISA technique. Serum IL6 (pg/mL) was performed using an automatic immunoassay system (Immulite 1000, Siemens- Germany). Comparing the two groups, our results revealed significantly increased serum levels for XOR (6.2�1.5 / 3.9�1.1); OXSR1 (11.3�2.9 / 6.2�2.1) and IL6 (7.0�1.2 / 5.0�0.4). Patients� serum levels of TAC were significantly decreased compared with the control group values (25.2�3.9 / 33.5�2.8). It becomes more and more obvious that oxidative stress is an important element initiating diabetic microvascular complications, including diabetic kidney disease. Our results suggested that XOR should be regarded as an important target in the attempt to reduce oxidative stress in the context of diabetic kidney disease.

Uric acid – history, present and future

“…interestingly, ascorbate by itself is not able to prevent the reaction between peroxynitrite and tetrahydrobiopterin. this illustrates the major role of uric acid on the peroxynitrite scavenging scene (5).…”

“…During primates evolution the loss of ascorbate synthetase was followed by the loss of uricase. Most probably, blood uric acid replaced or supplemented the antioxidant functions of ascorbate during primates evolution (3,5).…”

“…Uric acid represents a powerful antioxidant capable of scavenging singlet oxygen molecules, oxygen radicals, and peroxynitrite (OnOO−) molecules. Uric acid molecule also can chelates transition metals in order to reduce ion-mediated ascorbic acid oxidation (5). Duet o its chemical structure, uric acid is responsible for approximately 50% of serum antioxidant activity (5).…”

“…Uric acid molecule also can chelates transition metals in order to reduce ion-mediated ascorbic acid oxidation (5). Duet o its chemical structure, uric acid is responsible for approximately 50% of serum antioxidant activity (5). the uric acid molecule can be regarded as an exceptional peroxynitrite (OnOO -) scavenger in the extracellular fluid (6).…”

Renal affectation in polyrheumatoid arthritis

“…An in- creased level of inflammation, commonly identified in patients with stage 5 CKD (End-Stage Renal Disease -ESDR), is an important trigger for lowering survival of patients [5]. In diabetic patients, literature studies increasingly describe the association between oxidative stress and microvascular complications, including diabetic kidney disease [6]. The occurrence of nephropathy in diabetic patients is associated with lower life expectancy and an increased mortality risk [7].…”