8-hydroxy-2--deoxyguanosine and Ischemia

Exercise is recommended for the management of type 2 diabetes, but its effects on diabetic nephropathy (DN) are still unknown. We hypothesized that appropriate exercise improves early DN via attenuation of inflammation and oxidative damage. Type 2 diabetic KK-A(y) mice, a spontaneous DN model, underwent two different kinds of exercise (i.e., moderate and low intensity). Sedentary mice or those undergoing an exercise regimen causing no significant body weight loss were used. We examined the urinary excretion of albumin, number of podocytes and macrophages, renal expressions of HIF-1α and MCP-1, and biomarkers of oxidative stress such as urinary 8-OHdG and serum SOD. Exercise reduced urinary levels of albumin and also maintained the number of podocytes in the exercised KK-A(y) mice independently of improvements of overweight and hyperglycemia, although moderate-intensity exercise increased expression of HIF-1α. Sedentary KK-A(y) mice showed increased expression of MCP-1 and infiltration of macrophage, increased urinary 8-OhdG, and decreased serum SOD levels compared with exercised KK-A(y) mice. On the whole, low-intensity exercise attenuates progression of early DN without affecting marked renal ischemia. Reduction rates of urinary albumin and maintained podocyte numbers, with parallel improvements in oxidative damage and inflammation, are related to beneficial effects of exercise in diabetic kidney disease.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Albumins; Animals; Biomarkers; Cell Proliferation; Chemokine CCL2; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Ischemia; Macrophages; Male; Mice; Oxidative Stress; Podocytes; Rats; Superoxide Dismutase

We previously demonstrated that prehabilitation by running on a treadmill leads to improved survival after gut ischemia reperfusion (I/R) in mice. The purpose of this research was to examine whether prehabilitation attenuates inflammatory responses after gut I/R in mice.. Male C57BL/6J mice (n = 92) were assigned to the sedentary (n = 46) or the exercise (n = 46) group. The exercise group ran on a treadmill for 4 wk, while the sedentary mice did not exercise. After the 4-week pretreatment, all mice underwent gut I/R and the blood, urine, small intestine, lung, liver, and gastrocnemius were harvested prior to ischemia or at 0, 3, 6, or 24 h after reperfusion. Histologically demonstrated organ damage, cytokine levels in the blood, gut and gastrocnemius, myeloperoxidase activity in the gut, 8-hydroxy-2'-deoxyguanosine levels in urine and the gut, and adenosine triphosphate (ATP) and ATP + ADP + adenosine monophosphate levels in the gut and gastrocnemius were evaluated.. The treadmill exercise reduced gut and lung injuries at 3 h and liver injury at 6 h after reperfusion. Running on the treadmill also decreased proinflammatory cytokine levels in the blood at 6 h, gut at 3 h and gastrocnemius at 6 h after reperfusion, myeloperoxidase activity in the gut prior to ischemia, and 6 h after reperfusion and the urinary 8-hydroxy-2'-deoxyguanosine level at 24 h after reperfusion, while ATP levels in exercised mice prior to ischemia and 3 h after reperfusion were increased in the intestine as compared to the levels in sedentary mice.. Prehabilitation with treadmill exercise reduces inflammatory responses after gut I/R and may exert protective actions against gut I/R.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenosine Triphosphate; Animals; Antioxidants; Cytokines; Ischemia; Male; Mice; Mice, Inbred C57BL; Peroxidase; Physical Conditioning, Animal; Preoperative Exercise; Reperfusion Injury

Oxidative damage is critical in the pathogenesis of ovarian ischaemia/reperfusion (I/R) injury, and statins have been reported to exert antioxidant activity. However, the role of VCAM-1 and xanthine oxidase (XO)/uric acid (UA) in ovarian I/R injury is not known. Also, whether or not atorvastatin exerts antioxidant activity like other statins is unclear.. This study investigated the involvement of VCAM-1 and XO/UA in ovarian I/R injury and the likely protective role of atorvastatin.. Forty female Wistar rats were randomized into sham-operated, ischaemia, ischaemia/reperfusion (I/R), ischaemia and atorvastatin, and I/R and atorvastatin.. In comparison with the sham-operated group, atorvastatin blunted ischaemia and I/R-induced distortion of ovarian histoarchitecture and follicular degeneration. Also, atorvastatin alleviated ischaemia and I/R-induced rise in XO, UA, and malondialdehyde, which was accompanied by inhibition of ischaemia and I/R-induced reductions in reduced glutathione level, enzymatic antioxidant activities and increase in myeloperoxidase activity and TNF-α and IL-6 levels by atorvastatin treatment. Additionally, atorvastatin blocked ischaemia and I/R-induced increase in VCAM-1 expression, caspase 3 activity, 8-hydroxydeoxyguanosine level and ovarian DNA fragmentation index.. For the first time, this study revealed that atorvastatin-mediated downregulation of VCAM-1 and XO/UA/caspase 3 signaling averts oxidative injury, inflammation, and apoptosis induced by ovarian ischaemia/reperfusion injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Apoptosis; Atorvastatin; Caspase 3; Down-Regulation; Female; Glutathione; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Interleukin-6; Ischemia; Malondialdehyde; Oxidative Stress; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury; Tumor Necrosis Factor-alpha; Uric Acid; Vascular Cell Adhesion Molecule-1; Xanthine Oxidase

This study investigated the protective effect of human amniotic fluid-derived stem cells (hAFSCs) against bladder overactivity in rat model of atherosclerosis-induced chronic bladder ischemia.. Adult female Sprague-Dawley rats were divided into six groups: (1) Normal control with a regular diet for 8 weeks, (2) Sham-operation, (3) arterial balloon endothelial injury (AEI) of common iliac artery (AEI only), and post-AEI consecutive hAFSCs treatment for (4) 1 day, (5) 3 days, and (6) 7 days. Groups 2-6 were given 2% cholesterol diet for 8 weeks after operation (sham or AEI). Bladder functions were analyzed by cystometry at 8 weeks in controls and after operation in groups 2-6. Wall morphology of common iliac artery was examined by hematoxylin and eosin stain. Bladder oxidative stress and inflammatory markers were studied by immunohistochemistry of 8-hydroxy-2'-deoxyguanosine (8OHdG), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-alpha).. Bladder overactivity with decreased voided volumes and intercontraction intervals and increased residual volumes was seen in AEI only group, but improved after hAFSCs treatment for 1, 3, and 7 days. Compared with controls and shams, the wall thickness of iliac artery was increased in AEI only group, but improved after hAFSCs treatment for 3 and 7 days. The expressions of 8OHdG, MDA, and TNF-alpha were increased in AEI only group, but improved after hAFSCs treatment for 1, 3, and 7 days.. Bladder overactivity caused by chronic bladder ischemia can be improved by hAFSCs treatment, probably by acting through down-regulation of oxidative stress and TNF-alpha expressions.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Amniotic Fluid; Animals; Deoxyguanosine; Disease Models, Animal; Female; Ischemia; Malondialdehyde; Oxidative Stress; Rats; Rats, Sprague-Dawley; Stem Cells; Treatment Outcome; Urinary Bladder; Urinary Bladder, Overactive

To further characterize, in a rat model, the effects of atherosclerosis-induced chronic bladder ischemia on bladder function and associated changes in oxidative stress markers and proinflammatory cytokines.. Adult Sprague-Dawley male rats were divided into three groups (arterial endothelial injury: AI, sham, naïve). The AI group (n = 14) underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet. The sham group (n = 12) underwent sham operation and received a 2% cholesterol diet. The naïve group (n = 12) received a regular diet. After 8 weeks, cystometrograms (CMG) without anesthesia or restraint were performed. In bladders from each group, oxidative stress markers (8-hydroxy-2'-deoxyguanosine: 8-OHdG; malondialdehyde: MDA) and proinflammatory cytokines (IL-8 like cytokine CXCL1/CINC-1, TNF-α, IL-6) were quantified. Histological examination of the iliac arteries was also performed.. At 8 weeks, the body and bladder wet weights were not significant different among the three groups. The micturition interval in the AI group decreased significantly compared with those in the other two groups, but maximum pressure during micturition did not change. The iliac arteries in the AI group revealed thickening of intima as well as diffuse media fibrosis at the sites of balloon injury. The levels of oxidative stress markers and proinflammatory cytokines were significantly higher in the AI than in the other groups.. Oxidative stress and inflammation may be key factors in the development of bladder overactivity in atherosclerosis-induced chronic bladder ischemia.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Atherosclerosis; Biomarkers; Chronic Disease; Cytokines; Deoxyguanosine; Disease Models, Animal; Iliac Artery; Ischemia; Male; Malondialdehyde; Oxidative Stress; Rats; Rats, Sprague-Dawley; Up-Regulation; Urinary Bladder; Urinary Bladder, Overactive; Urination; Urodynamics

To clarify the mechanism by which chronic bladder ischemia causes bladder functional changes, and to investigate the involvement of oxidative stress and pro-inflammatory cytokines, and the effects of the phytotherapeutic drug, Eviprostat, on these biochemical marker levels and bladder function.. Male Sprague-Dawley rats aged 15 weeks were divided into three groups. Arterial injury was experimentally induced by balloon endothelial injury of the iliac arteries, and a 2% cholesterol diet was given for 8 weeks. Rats in the arterial-injury group were given daily oral vehicle or Eviprostat, whereas sham-operated animals on a regular diet (0.09% cholesterol) were given vehicle for the last 2 weeks. Eight weeks after surgery, the levels of bladder pro-inflammatory cytokines, as well as bladder and urinary oxidative-stress markers, were determined. Cystometrograms were carried out without anesthesia or restraint.. Bladder and urinary oxidative-stress markers, and bladder pro-inflammatory cytokine levels were significantly increased in the arterial-injury group, and Eviprostat markedly suppressed these increase. The cystometrograms showed that arterial injury decreased the intermicturition interval without affecting the micturition pressure. This decrease was reversed by Eviprostat treatment.. Oxidative stress and pro-inflammatory cytokines might be involved in the development of overactive bladder by atherosclerosis-induced chronic bladder ischemia. Eviprostat might provide an attractive treatment option for individuals with bladder dysfunction due to chronic bladder ischemia because of its anti-oxidant and anti-inflammatory properties.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Atherosclerosis; Deoxyguanosine; Drug Combinations; Ethamsylate; Interleukin-8; Ischemia; Male; Malondialdehyde; Models, Animal; Oxidative Stress; Plant Extracts; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Urinary Bladder; Urinary Bladder, Overactive; Urination; Urodynamics

Paraplegia is a serious complication of operations on the thoracic and thoracoabdominal aorta. To investigate the mechanism by which motor neurons are damaged during these operations, we have reported a rabbit model of spinal cord ischemia. We also tested whether a free radical scavenger MCI-186 that is useful for treating ischemic damage in the brain can protect against ischemic spinal cord damage.. Fifteen minutes of ischemia was induced, then MCI-186 or vehicle was injected intravenously. Cell damage was analyzed by observing the function of the lower limbs and by counting the number of motor neurons. To investigate the mechanism by which MCI-186 prevents ischemic spinal cord damage, we observed the immunoreactivity of 8-hydroxy-2'-deoxyguanosine as an oxidative DNA damage marker and redox effector as a DNA repair marker.. In sham control, 8-hydroxy-2'-deoxyguanosine was not observed, and the nuclear expression of redox effector was observed. In vehicle injection group (group I), the nuclear expression of 8-hydroxy-2'-deoxyguanosine was observed at 1 and 2 days after reperfusion. The nuclear expression of redox effector was observed at 8 hours and 1 day, and disappeared at 2 days after transient ischemia. In MCI-186 injection group (group M), the nuclear expression of 8-hydroxy-2'-deoxyguanosine was not observed, and redox effector was observed at 8 hours and 1 and 2 days.. These results suggest that redox effector decreased in motor neurons after transient ischemia and this reduction preceded oxidative DNA damage. MCI-186 works as a radical scavenger and reduced oxidative DNA damage, so redox effector did not disappear. MCI-186 could be a strong candidate for a use as a therapeutic agent in the treatment of ischemic spinal cord injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antipyrine; Apoptosis; Ataxia; Biomarkers; Cell Count; Cell Nucleus; Deoxyguanosine; DNA Damage; DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Edaravone; Free Radical Scavengers; Ischemia; Male; Models, Animal; Motor Neurons; Nerve Tissue Proteins; Oxidation-Reduction; Oxidative Stress; Paraplegia; Postoperative Complications; Rabbits; Spinal Cord

The role of glycine has not been investigated in lung ischemia-reperfusion injury after cold preservation. Furthermore, the role of apoptosis after reperfusion following cold preservation has not been fully understood.. Lewis rats were divided into three groups (n=6 each). In the GLY(-) and GLY(+) groups, isolated lungs were preserved for 15 hr at 4 degrees C after a pulmonary artery (PA) flush using our previously developed preservation solution (ET-K; extracellular-type trehalose containing Kyoto), with or without the addition of glycine (5 mM). In the Fresh group, isolated lungs were reperfused immediately after a PA flush with ET-K. They were reperfused for 60 min with an ex vivo perfusion model. Pulmonary function, oxidative stress, apoptosis, and tumor necrosis factor (TNF)-alpha expression were assessed after reperfusion.. Shunt fraction and peak inspiratory pressure after reperfusion in the GLY(-) group were significantly higher than those in the GLY(+) and Fresh groups. Oxidative damage and apoptosis in the alveolar epithelial cells of the GLY(-) group, assessed by immunohistochemical staining and quantification of 8-hydroxy-2'-deoxyguanosine and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling method, were significantly higher than those of the GLY(+) and Fresh groups. There were correlations among shunt fraction, oxidative damage, and apoptosis. There was no expression of TNF-alpha messenger RNA in all groups evaluated by the reverse transcription-polymerase chain reaction.. Glycine attenuates ischemia/reperfusion injury after cold preservation by reducing oxidative damage and suppressing apoptosis independent of TNF-alpha in this model. The suppression of apoptosis might ameliorate lung function after reperfusion.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis; Blood Pressure; Cryopreservation; Cytoprotection; Deoxyguanosine; Glycine; Immunohistochemistry; In Situ Nick-End Labeling; Inhalation; Ischemia; Lung; Male; Oxidative Stress; Pressure; Pulmonary Artery; Pulmonary Circulation; Rats; Rats, Inbred Lew; Reperfusion Injury; Staining and Labeling

Reperfusion injury is considered primarily an inflammatory response to oxidative stress. In vitro, oxygen free radicals induce the formation of oxidized phospholipids with platelet-activating factor (PAF) activity (PAF-like lipids). We examined the following: 1) whether PAF and PAF-like lipids are released during reperfusion; 2) the relationship between these phospholipids and oxidative damage on the one hand, and leukocyte recruitment in renal tissue on the other; and 3) whether antioxidant treatment influences the behavior of these phospholipids, the renal inflammatory response, and the outcome of postischemic acute renal failure. After 60 min of warm renal ischemia in rabbits, a release of PAF and, particularly, PAF-like lipids was seen in the first 15 min of reperfusion. In addition, the release of those phospholipids was associated with intense tissue DNA oxidation and with an increase in myeloperoxidase activity. Vitamin C was able to attenuate these postischemic oxidative changes, decrease PAF and PAF-like lipid levels, and, consequently, reduce myeloperoxidase activity. After 40 min of warm renal ischemia in rats, vitamin C treatment ameliorated renal function and structure. This is the first in vivo demonstration of the release of phospholipid oxidation products as part of an oxidative-inflammatory response after renal ischemia-reperfusion, with the release of phospholipid oxidation products significantly reduced by antioxidant treatment.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Ascorbic Acid; Creatinine; Deoxyguanosine; DNA Damage; Inflammation; Ischemia; Kidney; Lipoproteins, LDL; Oxidative Stress; Platelet Activating Factor; Rabbits; Rats

Ischemia-reperfusion (IR) injury is an intractable process associated not only with therapeutic recanalization of vessels, but also with partial resection or transplantation of solid organs including liver. To develop methods for predicting the degree of hepatic IR injury and further to identify injured cells, we studied the formation of 8-hydroxy-2'-deoxy-guanosine (8-OHdG) and 4-hydroxy-2-nonenal (HNE)-modified proteins in the normothermic hepatic IR model of rats using immunohistochemistry, high-performance liquid chromatography (HPLC) determination and Western blot. The Pringle maneuver for either 15 or 30 min duration produced reversible or lethal damage, respectively. The levels of both products were significantly increased in proportion to ischemia duration 40 min after reperfusion, suggesting the involvement of hydroxyl radicals. Increased immunoreactivity of 8-OHdG was observed not only in the nuclei of hepatocytes but also in those of bile canalicular and endothelial cells. However, immunoreactivity of HNE-modified proteins was detected in the cytoplasm of hepatocytes, which was confirmed by Western blot, and in addition, in the nuclei of hepatocytes after severe injury. Thus, localization of the two oxidatively modified products was not identical. Our data suggest that these two products could be used for the assessment of hepatic IR injury in tissue, but that the biological significance of the two products might be different.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Blotting, Western; Body Temperature; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Adducts; DNA Damage; Hepatocytes; Hydroxyl Radical; Immunoenzyme Techniques; Ischemia; Liver; Liver Function Tests; Male; Molecular Weight; Nuclear Proteins; Oxidation-Reduction; Oxidative Stress; Proteins; Rats; Rats, Wistar; Reperfusion Injury; Specific Pathogen-Free Organisms; Time Factors

Nitric oxide has a clearly defined place in normal renal homoeostasis while there is a continuing debate as to its role under pathophysiological conditions. This study investigated the role of nitric oxide in a model of renal warm ischaemia-reperfusion injury.. Groups of rats underwent bilateral renal warm ischaemia (for 15-60 min) followed by reperfusion (20 or 80 min) before unilateral nephrectomy for measurement of renal nitric oxide (as nitroxides) and oxidative damage. Renal function was measured on days 2 and 7 before killing and nephrectomy. A further group received the nitric oxide synthase inhibitor N(G)-nitro L-arginine methyl ester (L-NAME; 50 mg per kg body-weight) before induction of warm ischaemia.. In early reperfusion there was a correlation between the duration of warm ischaemia (15-45 min) and renal nitrate (r2=0.97) which increased from a mean(s.e.m.) baseline value of 95(5.9) to 208(17.3) nmol per mg protein following 45 min of warm ischaemia. Levels were further raised at 80 min and maintained through to day 7 (241(12.5) nmol per mg protein in 45-min group). This rise was attenuated by L-NAME (P< 0.01) as was the early rise in oxidative damage seen otherwise. By day 7, however, oxidative damage was increased (all P< or = 0.01).. Renal nitric oxide increased early in recoverable warm ischaemia-reperfusion injury and remained raised to day 7. Nitric oxide synthase inhibition ameliorated early but exacerbated late damage suggesting that the early burst of nitric oxide is cytotoxic but that overall nitric oxide may exert a cytoprotective effect.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; DNA Damage; Glomerular Filtration Rate; Hot Temperature; Ischemia; Kidney; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Rats; Rats, Wistar; Reperfusion Injury