thiobarbituric-acid and Reperfusion-Injury

To evaluate the efficacy of N-acetyl cysteine (NAC) in lower extremity ischemia/reperfusion.. A total of 23 patients who underwent surgical intervention due to acute femoral artery occlusion were assigned into 2 groups: control group (group 1, n=12); and NAC group (group 2, n=11). Patients in NAC group received NAC before reperfusion, and 8 and 16 h after reperfusion (3x300 mg), while patients in control group received only NaCl 0.9% (3x100 mL). Catalase, malondialdehyde (MDA) and thiol concentrations were determined in femoral vein samples collected at 6 different time points: before reperfusion (t1), and 30 min (t2), 2 h (t3), 6 h (t4), 12 h (t5) and 24 h (t6) after reperfusion. Alveolar-arterial oxygen gradient (A-aO2) was calculated in radial artery blood samples simultaneously collected at the same time points.. No significant differences between the two groups with regard to age (control group 61+/-13 and NAC group 64+/-11 years), gender (control group M/F: 7/5, NAC 6/5) and the average time from onset of symptoms (control group 9.6+/-3.5 h, and NAC group 10.2+/-3.1 h) were present. Catalase enzyme activity increased with reperfusion in both groups and there were no differences between the two groups. MDA levels did not change significantly with reperfusion in NAC group, whereas they were significantly higher in control group at t2 and t3 compared to NAC group (P<0.05). Thiol concentrations decreased with reperfusion in control group, and in NAC group increases that started with reperfusion returned back to baseline levels after 24 hours. Although the A-aO2 gradient increased in both groups with the beginning of reperfusion, the most prominent increase occurred in control group (P<0.05).. In control group, the significant increase in MDA levels and A-aO2 gradient in reperfusion phase were considered a sign of local and end organ injury. We did not observe these changes in NAC performed group thus showing the efficacy of NAC.

Topics: Acetylcysteine; Biomarkers; Blood Gas Analysis; Catalase; Embolectomy; Embolism; Female; Femoral Artery; Free Radical Scavengers; Humans; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Reperfusion Injury; Spectrophotometry; Thiobarbiturates; Treatment Outcome; Ultrasonography, Doppler, Color

To evaluate the effects of hypertonic saline solution associated to remote ischemic perconditioning in renal ischemia/reperfusion injury in rats.. Twenty five male rats (Wistar) underwent right nephrectomy and were distributed into five groups: Sham group (S); Ischemia/Reperfusion group (I/R) with 30 minutes of renal ischemia; Remote ischemic perconditioning group (Per) with three cycles of 10 minutes of I/R performed during kidney ischemia; Hypertonic saline solution group (HSS) treated with hypertonic saline solution (4ml/kg); remote ischemic perconditioning + Hypertonic saline solution group (Per+HSS) with both treatments. After reperfusion, blood samples were collected for BUN and creatinine serum levels analyzes. TBARS were evaluated in plasma and renal tissue to assess oxidative stress. Kidney histopathological examination were performed.. Per+HSS group showed a lower degree of renal dysfunction in relation to I/R group, whereas the technique of remote ischemic perconditioning isolated or associated with saline solution significantly reduced oxidative stress and histological damage.. Remote ischemic perconditioning associated or not to saline solution promoted reduction of acute renal injury induced by ischemia/reperfusion.

Topics: Animals; Blood Urea Nitrogen; Creatinine; Ischemia; Ischemic Preconditioning; Kidney; Kidney Function Tests; Male; Necrosis; Oxidative Stress; Protective Agents; Random Allocation; Rats, Wistar; Reperfusion Injury; Reproducibility of Results; Saline Solution, Hypertonic; Thiobarbiturates; Time Factors; Treatment Outcome

Ischemia/reperfusion (I/R) injury is characterized by the production of oxygen-free radicals leading to disturbances in vasomotility (microvascular constriction) and microvascular permeability (interstitial edema formation). The objective was to evaluate the effect of the combined antioxidative and enzymatic preparation Phlogenzym on I/R injury of skeletal muscle.. A rabbit hindlimb model of I/R (2.5/2 h) was used (IR group). Phlogenzym, containing rutin, trypsin, and bromelain, was applied enterally (60 mg/kg body weight) as a bolus 30 min prior to ischemia (Ph group). Sham-operated animals served as controls (CO group). Plasma malondialdehyde, potassium, and microvascular perfusion (monitored by laser flowmetry) were assessed. Histomorphometry and electron microscopy were performed from major adductor muscles.. Two hours after reperfusion, potassium levels were significantly elevated in IR compared to Ph group (6.7 +/- 1.2 versus 4.9 +/- 0.9 mmol/l, P < 0.006). Enhanced lipid peroxidation, apparent by increased plasma malondialdehyde levels, was ameliorated in the Ph group (1.0 +/- 0.1 versus 0.7 +/- 0.1 nmol/ml, P < 0.0001). No-reflow (reduction of blood flow by 62% in IR group) was not observed in the Ph group (P < 0.004). Phlogenzym treatment prevented microvascular constriction (17.6 +/- 2.3 versus 12.6 +/- 1.1 microm(2), P < 0.0001) and mollified interstitial edema (21.5 +/- 2.0 versus 26.0 +/- 3.7%, P < 0.017), resulting in mild ultrastructural alterations in contrast to pronounced sarcolemmal and mitochondrial damage in untreated rabbits.. Phlogenzym had a protective effect on skeletal muscle during I/R injury expressed by prevention of no-reflow and preservation of muscle tissue.

Topics: Animals; Antioxidants; Blood Pressure; Bromelains; Capillaries; Drug Combinations; Hydrogen-Ion Concentration; Lipid Peroxides; Male; Malondialdehyde; Microcirculation; Microscopy, Electron; Muscle Fibers, Skeletal; Muscle, Skeletal; Potassium; Rabbits; Reperfusion Injury; Rutin; Thiobarbiturates; Trypsin

The aim of this study was to investigate any possible protective effect of ketamine in acute muscular ischaemia and reperfusion injury by measuring malondialdehyde using thiobarbituric acid assay in rats.. Twelve female Wistar albino rats were anaesthetized with chloral hydrate and randomly assigned into two groups to receive ketamine 1 mg kg(-1) min(-1) or saline infusion. Blood and gastrocnemius muscle samples were obtained 10 min after onset of infusion, before ischaemia. Then, femoral arteries were clamped for 30 min. Blood and muscle samples were obtained at the 30th minute of ischaemia and 10 min after reperfusion.. Muscle malondialdehyde concentrations were 27.88 +/- 2.45, 27.62 +/- 3.98 before ischaemia, 32.10 +/- 4.19, 30.77 +/- 2.73 in the 30th minute of ischaemia and 44.34 +/- 2.45, 34.83 +/- 2.78 after reperfusion in saline and ketamine-treated rats, respectively (nmol g(-1), mean +/- SD). The muscle malondialdehyde level after reperfusion was lower in ketamine-treated rats compared to saline group (P < 0.002). Plasma malondialdehyde levels were 3.77 +/- 0.16, 3.78 +/- 0.18 before ischaemia, 3.81 +/- 0.25, 4.00 +/- 0.86 at the 30th minute of ischaemia and 4.00 +/- 0.53, 3.94 +/- 0.95 after reperfusion, respectively, in saline and ketamine-treated rats (micromol L(-1), mean +/- SD). The effect of ketamine on muscular malondialdehyde was not observed in concurrent plasma malondialdehyde levels.. Ketamine was found to attenuate acute ischaemia-reperfusion injury in muscle tissue in rats (muscular protective). Ketamine may attenuate lipid peroxidation in muscle tissue in tourniquet-requiring manoeuvres.

Topics: Anesthetics, Dissociative; Animals; Female; Ischemia; Ketamine; Lipid Peroxidation; Lipid Peroxides; Malondialdehyde; Muscle, Skeletal; Protective Agents; Random Allocation; Rats; Rats, Wistar; Reperfusion Injury; Sodium Chloride; Thiobarbiturates; Time Factors

Zinc may have an antioxidant effect mediated by induction of metallothionein. Based on the assumption that metallothionein can scavenge oxygen free radicals, we examined whether zinc administration prior to renal ischemia would improve renal dysfunction caused by ischemia-reperfusion injury in rats. Wistar rats weighing 265 g were treated with an intraperitoneal injection of 20 mg/kg zinc 24 h prior to the renal ischemia-reperfusion procedure, which was achieved by a 30-min clamping of the bilateral renal vessels and subsequent 90-min reperfusion. Thirty-minute renal clearance tests were performed before and after renal ischemia in zinc- (n = 11) and saline-treated (n = 8) rats. Thiobarbituric acid reactive substance, conjugated diene, and metallothionein levels in the renal tissues were also determined. Sham-operated rats (n = 5 in each treatment) served as control for the ischemia-reperfusion rats. Ischemia-reperfusion resulted in significantly lower glomerular filtration rate values and marked increases in tissue concentrations of thiobarbituric acid reactive substance and conjugated diene compared with sham-operation. Zinc administration improved the reduced glomerular filtration rate values seen after the ischemia-reperfusion procedure, but not to the extent of pre-ischemic levels. Zinc pretreatment significantly reduced the increased levels of thiobarbituric acid reactive substance and conjugated diene during ischemia-reperfusion and increased metallothionein levels compared with saline injection. These findings suggest that zinc has an antioxidant effect mediated through the induction of metallothionein, but appears only to have a minor protective effect on renal function induced by renal ischemia-reperfusion injury.

Topics: Acute Kidney Injury; Animals; Antioxidants; Disease Models, Animal; Glomerular Filtration Rate; Kidney; Lipid Peroxidation; Male; Metallothionein; Rats; Rats, Wistar; Reactive Oxygen Species; Renal Circulation; Reperfusion Injury; Thiobarbiturates; Treatment Outcome; Zinc

The aim of this study was to investigate the extent to which ischemia and reperfusion lead to oxidative damage of the retinal tissue and investigate how ischemic and reperfused retinal tissues react to the application of perfluorooctylbromide (PFOB) and, if this reaction can be influenced by protective drugs such as vitamin E (Vit.E). The experiments were performed with 60 male Wistar rats, divided into 12 groups using an established model of reversible ischemia and reperfusion of the globe. Grouping of animals was carried out according to different ischemia and reperfusion periods and different therapeutic regimens (PFOB, Vit.E). Treatment with PFOB and/or Vit.E was performed after 60 min of ischemia with 60 min of reperfusion. At the end of the experiments thiobarbituric acid reactive substances (TBARS) were determined in the retinal tissues and served as parameters of oxidative tissue damage. Ischemia of up to 60 min led to a significant increase in TBARS values. Ninety and 120 min of ischemia led to no further significant elevation compared to the 60 min or 90 min group. Following 60 min of ischemia, a reperfusion period of 15 min led to an increase in TBARS values that was significant (P<0.05) after 30 and 60 min. Addition of PFOB resulted in a further significant (P<0.05) increase in TBARS values as compared to the respective group without treatment. Vit. E alone did not change the values significantly compared to the respective group without treatment. However, the application of Vit.E in addition to PFOB led to a significant reduction in TBARS values. Ischemia resulted in severe oxidative retinal tissue damage, which increased during reperfusion. The reperfusion damage might be due to the known depletion of protecting substances such as vitamin E. Enhancement of oxygen supply by PFOB during reperfusion without any tissue protection leads to more severe damage. Thus, additional protection of the tissue by powerful antioxidants is necessary when providing oxygen for better tissue recovery.

Topics: Animals; Fluorocarbons; Hydrocarbons, Brominated; Ischemia; Male; Peroxides; Rats; Rats, Wistar; Reperfusion Injury; Retina; Retinal Diseases; Thiobarbiturates; Time Factors; Vitamin E

Oxygen free radicals may be implicated in the pathogenesis of ischemia-reperfusion damage. It is known that 2-chloroadenosine (2-CADO) has neuromodulatory effects and prevents the neuronal damage seen in the period of postischemia reperfusion. However, direct effects of 2-CADO on lipid peroxidation have not been investigated previously. The attack on the cell membrane by free radicals leads to lipid peroxidation, which can be assayed by the malondialdehyde (MDA) level. The aim of this study was to determine the effect of 2-CADO therapy on lipid peroxidation in experimental forebrain ischemia and postischemia reperfusion in Mongolian gerbils. Cerebral ischemia was induced by a bilateral 30-mm occlusion of the common carotid arteries. 2-Chloroadenosine (0.6 mg/kg, IV) was administered 5 min subsequent to ischemia. Ischemia was followed by reperfusion for 30 min. The MDA level was measured by the thiobarbituric acid (TBA) test. Bilateral carotid artery occlusion for 30 min in gerbils resulted in no significant change in MDA level in the brain. The MDA level was higher in postischemia reperfusion than in the ischemic group. 2-Chloroadenosine treatment did not change the MDA level in the ischemic period. However, the MDA level recovered significantly upon 2-CADO therapy during reperfusion following ischemia. These results suggest that 2-CADO may offer some degree of protection against oxidative stress in cerebral ischemia-reperfusion damage.

Topics: 2-Chloroadenosine; Animals; Drug Evaluation, Preclinical; Female; Gerbillinae; Lipid Peroxidation; Lipid Peroxides; Male; Malondialdehyde; Neuroprotective Agents; Prosencephalon; Reperfusion Injury; Thiobarbiturates

The effect of 4 hours of ischemia followed by reperfusion for 1 hour has been studied in fully anesthetized rabbits. Muscles from the limb subjected to ischemia and reperfusion showed considerable ultrastructural damage, although the distribution of damage between muscles was not uniform (anterior tibialis > soleus > quadriceps). Damage to the muscle was associated with a significant increase in the concentration of some indicators of free radical-mediated processes (thiobarbituric acid-reactive substances and diene conjugates), although others (glutathione and protein sulfhydryl groups) were unchanged. Reperfused muscles also showed considerable changes in their calcium and sodium contents. Treatment of animals with dantrolene sodium (4 mg/hr) throughout the periods of ischemia and reperfusion was found to preserve the ultrastructural appearance of quadriceps, soleus and anterior tibialis muscles. No effect of dantrolene sodium on indicators of free radical activity or muscle cation content was seen.

Topics: Animals; Cations; Dantrolene; Glutathione; In Vitro Techniques; Infusions, Intravenous; Ischemia; Microscopy, Electron; Muscle Relaxants, Central; Muscle, Skeletal; Myofibrils; Rabbits; Reperfusion Injury; Technetium; Thiobarbiturates

This study examined whether ischemia-reperfusion injury to skeletal muscle could be reduced by post-ischemic infusion of phosphoenolpyruvate (PEP) and adenosine triphosphate (ATP). The rectus femoris muscle of 54 rabbits was rendered ischemic for 3.5 hr. Eighteen rabbits received no further treatment. Thirty-six were infused intra-arterially at the end of ischemia, 18 with vehicle alone, and 18 with a mixture of PEP (80 mumol/kg) and ATP (2.6 mumol/kg). Six rabbits from each group were explored after 24 hr reperfusion and the muscles assessed for viability (by nitro blue tetrazolium), ATP (by luciferin-luciferase chemiluminescence), malonyldialdehyde (MDA) (thiobarbituric acid method), and water content. The remaining muscles in each group were examined histologically after either 1 hr or 4 days of reperfusion. At 24 hr the viability of the PEP/ATP infused muscles (78.9 +/- 15.4 percent) was significantly greater than that of untreated (41.4 +/- 27.3 percent) or vehicle-infused groups (34.0 +/- 32.7 percent). ATP stores were significantly higher and MDA (indicative of free radical activity) and water content significantly lower in the PEP/ATP treated group. At 24 hr and 4 days, muscles infused with PEP/ATP showed less necrosis and fewer infiltrating neutrophils than the untreated groups. Studies with isolated rabbit neutrophils showed that ATP alone significantly inhibited superoxide anion production by stimulated neutrophils. However, when combined with PEP at concentrations similar to those achieved in vivo, ATP did not significantly affect superoxide production. The findings indicate that post-ischemic infusion of PEP/ATP significantly reduces ischemia-reperfusion injury in rabbit skeletal muscle. The protective effect of PEP/ATP is more likely to be due to supplementation of intracellular ATP stores than to the inhibition of superoxide production by infiltrating neutrophils.

Topics: Adenosine Triphosphate; Animals; Body Water; Free Radicals; Indicators and Reagents; Injections, Intra-Arterial; Ischemia; Luminescent Measurements; Malondialdehyde; Muscle, Skeletal; Necrosis; Neutrophils; Nitroblue Tetrazolium; Pharmaceutical Vehicles; Phosphoenolpyruvate; Rabbits; Reperfusion Injury; Superoxides; Thiobarbiturates; Tissue Survival

We assessed the effects of the calcium channel blocker verapamil on postischemic oxidative injury in the rat liver. In the untreated rats, the values of tissue lipid peroxidation products (thiobarbituric acid-reactive substances) remained unchanged during 90 min of warm ischemia. However, the values increased significantly after the next 60 min of reperfusion compared with those in the sham-operated rats (P less than 0.01). Intravenous infusion of verapamil (5 micrograms.kg-1.min-1) significantly reduced the extent of lipid peroxidation during reperfusion compared with that in the untreated rats (P less than 0.02). The percentages of tissue water content and the serum lactate dehydrogenase activities after 60 min of reperfusion were significantly lower in the treated rats than in the untreated rats (P less than 0.02 and P less than 0.01, respectively). We also investigated the influence of verapamil on superoxide-generating activity determined by the superoxide-dependent cytochrome c reduction of peritoneal polymorphonuclear leukocytes (PMNs) harvested from normal, non-ischemic, and non-treated rats in vitro. This demonstrated that there was no apparent effect with the highest verapamil concentration level (8 microM) observed in the rat plasma during our experiment. These findings suggest that verapamil might reduce the postischemic oxidative injury in the rat liver by mechanisms perhaps not related to the suppression of rat PMNs superoxide-generating activity.

Topics: Animals; Body Water; Infusions, Intravenous; L-Lactate Dehydrogenase; Lipid Peroxidation; Liver Diseases; Male; Neutrophils; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxides; Thiobarbiturates; Verapamil

The influx of extracellular Ca2+ has been postulated to be one of the mediators of ischemia-reperfusion injury. A possible link between Ca2+ influx and oxygen radical generation has also been suggested. In the present study, using the isolated perfused rat liver, we evaluated the role of extracellular Ca2+ on oxygen radical generation, liver damage, and lipid peroxidation during 30 min ischemia and 60 min of reperfusion. Oxygen radical generation in the liver was continuously monitored by lucigenin-enhanced chemiluminescence. Liver damage and lipid peroxidation were evaluated by measuring lactate dehydrogenase (LDH) and thiobarbituric acid reactive substances (TBARS) release into the effusate, respectively. In the absence of extracellular Ca2+ (much less than 30 microM) oxygen radical generation from the liver increased gradually over 2 hr and there were concomitant increases in LDH and TBARS release. When livers were made ischemic and then reperfused, oxygen radical generation increased at the onset of reperfusion and then decreased over 30 min of reperfusion. After 30 min of reperfusion, livers reperfused with low Ca2+ buffer showed a linear increase in oxygen radical generation as well as progressive increases in LDH and TBARS release. On the other hand, livers reperfused with Ca2+ containing (1.25 mM) buffer showed no further increase in oxygen radical generation and no evidence of progressive liver damage and lipid peroxidation. These results suggest that Ca2+ overload is not a primary cause of liver ischemia-reperfusion injury and that the presence of extracellular Ca2+ during reperfusion is necessary to maintain normal liver function.

Topics: Acridines; Animals; Calcium; Free Radicals; Ischemia; L-Lactate Dehydrogenase; Liver; Oxygen; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Thiobarbiturates

In the past, antioxidant and chelator studies have implicated a role for iron-dependent oxidative damage in tissues subjected to ischaemia followed by reperfusion. As ferritin is a major source of iron in non-muscular organs and therefore a potential source of the iron required for oxygen radical chemistry, we have determined conditions under which ferritin iron reduction leads to the formation of a pool of iron which is capable of catalysing lipid peroxidation. Under anaerobic conditions and in the presence of rat liver microsomes, flavin mononucleotide (FMN) catalysed the reduction of ferritin iron as shown by both continuous spectrophotometric measurements of tris ferrozine-Fe(II) complex formation and post-reaction Fe(II) determination. The presence of either ferrozine or citrate was not found to alter the time course or extent of ferritin reduction. In contrast, the addition of air to the reactants after a 20 min period of anaerobic reduction resulted in peroxidation of the microsome suspension (as determined with the 2-thiobarbituric acid test) only in the presence of a chelator such as citrate, ADP or nitrilotriacetic acid. These results support the concept that reduced ferritin iron can mediate oxidative damage during reperfusion of previously ischaemic tissues, provided that chelating agents such as citrate or ADP are present.

Topics: Animals; Catalysis; Ferritins; Flavin Mononucleotide; Free Radicals; Iron Chelating Agents; Lipid Peroxidation; Microsomes, Liver; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Thiobarbiturates

The placement of rubber band tourniquets upon rat hind-limbs for 5 h followed by reperfusion of the extremities results in a severe form of circulatory shock characterized by hypotension and death within 24 h of tourniquet release. Oxidative damage to muscle tissue is an early consequence of hind-limb reperfusion on tourniquet release, yet this local damage does not explain the lethal hypotensive shock state which evolves within the next 24 h. Multiple system organ failure (MSOF), of as of yet unknown causes, is usually described in relation to several shock states. It has been suggested that injured or necrotic tissue may activate neutrophils, platelets, and the coagulation system leading to embolization in remote tissues. Effective decreases in hepatic blood flow have been observed in several forms of sepsis which precedes the biochemical evidence consistent with an ischemic insult of the liver. In support of our original hypothesis, that organ failure has its genesis in a primary perfusion abnormality with secondary ischemic organ injury, herein we have assessed the possibility that oxygen-derived free radicals are generated in the liver of rats after reperfusion of their hind-limbs on release of the tourniquets. We report on the protective effects of allopurinol (ALLO) and a mixture of superoxide dismutase (SOD) catalase (CAT) and dimethylsulfoxide (DMSO) on liver free sulfhydryl content (SH), thiobarbituric acid-reactive substances (TBARS), and on the release of aspartic acid (AsT) and alanine aminotransferase (AlT) activities, and of alkaline phosphatase during a 5 h tourniquet period and after 2 h of reperfusion of the hind-limbs. During the hind-limb ischemic period hepatis tissue SH levels remained essentially constant during the first hour (6.02 +/- 0.36 to 5.65 +/- 0.20 mumoles/g wet tissue), and decreased significantly, over and above the normal circadian decrease of liver glutathione levels, to 4.02 +/- 0.69 mumoles/g wet tissue after the third hour and remained lowered until tourniquet release. A further significant decrease (3.11 +/- 0.49 mumoles/g wet tissue) was observed after 2h of reperfusion. TBARS production remained constant during the 5 h hind-limb ischemic period (168.4 +/- 37.3 mumoles/g wet tissue) and rose by 55% to 261.7 +/- 55.8 mumoles/g wet tissue after 2 h of tourniquet release. ALLO, but not the SOD-CAT-DMSO combination, protected hepatic SH loss during the hind-limb ischemic insult, yet both offered protection after 2 h o

Topics: Alanine Transaminase; Alkaline Phosphatase; Animals; Aspartate Aminotransferases; Female; Free Radicals; Hindlimb; Ischemia; Liver; Liver Diseases; Male; Oxygen; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Shock; Sulfhydryl Compounds; Thiobarbiturates; Tourniquets

Using the isolated perfused rat liver, we investigated the relationship of glutathione (GSH) with reactive oxygen species (ROS) generation and liver cell damage during ischemia/reperfusion in normal and GSH-depleted conditions. Lucigenin-enhanced chemiluminescence was used as a sensitive index of tissue ROS generation. After 30 minutes of equilibration, livers were subjected to global ischemia for various times (60 or 90 minutes) and then reperfused for another 120 minutes. Intracellular ROS levels increased sharply at the onset of reperfusion and then declined slowly. After 30 to 60 minutes of reperfusion, ROS levels started to increase progressively in a linear fashion. However, sinusoidal glutathione disulfide release did not increase during reperfusion in the same livers, suggesting that intracellular ROS generation is too low to cause a significant increase in GSH oxidation. Pretreatment with phorone (300 mg/kg intrapentoneally [ip]), which reduced hepatic GSH by 90%, did not cause any difference in intracellular ROS generation compared with the control livers. There were also no significant differences in lactate dehydrogenase and thiobarbituric acid reactive substances (TBARS) release between the control and phorone-treated livers during reperfusion after various times of ischemia. These data indicate that ROS generation in the normal isolated perfused liver during ischemia/reperfusion is extremely low and intracellular GSH does not serve as a major intracellular defense system against such a low oxidative stress.

Topics: Acridines; Animals; Glutathione; Ischemia; Ketones; Kinetics; L-Lactate Dehydrogenase; Lipid Peroxidation; Liver; Luminescent Measurements; Male; Oxidation-Reduction; Oxygen; Rats; Rats, Inbred Strains; Reperfusion Injury; Thiobarbiturates

This study was designed to clarify the role of leukotrienes (LTs) in gastric injury induced by ischemia-reperfusion in rats. Gastric lesions were produced by clamping of the celiac artery and by reoxygenation following clamping. Administration of AA-861, a lipoxygenase inhibitor, significantly inhibited the increase in the total area of the gastric erosions and the increase in thiobarbituric acid-reactive substances in the gastric mucosa. Administration of YM-638, a peptide LT antagonist, showed protective effects similar to AA-861. These results suggest that the protective effects of AA-861 and YM-638 against ischemia-reperfusion-induced gastric injury were due to their antioxidative action.

Topics: Animals; Benzoquinones; Gastric Mucosa; Leukotrienes; Lipid Peroxidation; Lipoxygenase Inhibitors; Male; Rats; Rats, Inbred Strains; Reperfusion Injury; Thiadiazoles; Thiobarbiturates

In the present study, we quantified the biochemical [thiobarbituric acid (TBA) reactants, superoxide dismutase (SOD) and vitamin E] and histologic changes in the small intestinal tissue after ischemia and/or reperfusion. Sixty-seven Wistar rats were divided into 7 groups; N group: control, A-I group: 30 min. ischemia, A-II group: 120 min. ischemia, B-I group: Declamp after 30 min. ischemia, B-II group: 30 min. reperfusion after 30 min. ischemia, B-III group: 30 min. reperfusion after 120 min. ischemia, E group: vitamin E administration 30 min. reperfusion after 30 min. ischemia. The levels of TBA reactants were significantly different between A-II and B-II, B-II and E (all p less than 0.01). For SOD, there were significant differences between N and B-I (p less than 0.01), N and E (p less than 0.05). For vitamin E, there were significant differences between A-I and B-I, A-I and B-I, B-II and E (all p less than 0.01). Histologic changes showed that the grade of tissue injury was more severe in B-I and B-II than in A-I, and was less in E than in B-II. It is suggested that vitamin E protected cells from injury due to oxygen free radicals.

Topics: Animals; Free Radicals; Intestine, Small; Ischemia; Lipid Peroxides; Male; Oxygen; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxide Dismutase; Thiobarbiturates; Vitamin E

The protective effect of a novel synthetic zinc-carnosine chelate compound, zinc N-(3-aminopropionyl)-L-histidine (Z-103), on the gastric mucosal injury induced by ischemia-reperfusion was studied in rats. Ischemia and reperfusion injury was produced on the rat stomach by applying a small clamp to the celiac artery for 30 min and by removal of the clamp for 30 min. The decrease in the gastric mucosal blood flow was not influenced by the treatment with Z-103. The increase in total area of the erosions on the stomach after ischemia-reperfusion and the increase in lipid peroxides in the gastric mucosa were significantly inhibited by the oral administration of Z-103. In addition, Z-103 inhibited lipid peroxidation of rat brain homogenate and liver microsome in vitro. These results suggest that the protective effect of Z-103 against the aggravation of gastric mucosal injury induced by ischemia-reperfusion may be due to its inhibitory effect on lipid peroxidation.

Topics: Animals; Anti-Ulcer Agents; Antioxidants; Blood Flow Velocity; Carnosine; Cholesterol; Dipeptides; Gastric Mucosa; Lipid Peroxidation; Male; Organometallic Compounds; Oxidation-Reduction; Rats; Rats, Inbred Strains; Reperfusion Injury; Thiobarbiturates; Vitamin E; Zinc; Zinc Compounds

Endothelial cells may be damaged by oxygen reactive species produced by granulocytes, by transition metal ions or by xanthine oxidase, an enzyme present in great quantity in these cells. Since it has been observed that propionyl carnitine protects the heart from peroxidation, we have investigated the effect of this compound on the formation of thiobarbituric acid reactive oxidation products (TBAR) in endothelial membranes. The peroxidation systems used were a mixture of Fe3+ and Fe2+, hydrogen peroxide and Fe2+, or xanthine oxidase-- xanthine. Propionyl carnitine at millimolar concentrations decreases TBAR formation. The protection is concentration-dependent and is almost absent in the presence of propionate and carnitine. From these results it appears that propionyl carnitine may protect not only myocardium but also vessels from peroxidative damage that occurs during ischaemia and reperfusion.

Topics: Animals; Carnitine; Cattle; Cell Membrane; Cell Separation; Dose-Response Relationship, Drug; Endothelium, Vascular; Hydrogen Peroxide; Iron; Reperfusion Injury; Thiobarbiturates; Xanthine Oxidase

Glutathione status and products from lipid peroxidation [measured as thiobarbituric acid reactive substances (TBARS)] were determined in red and white muscle tissue of the rat. Marked differences between both muscle types were found in reduced glutathione (GSH) and oxidized glutathione (GSSG) content, exhibiting 163% and 183%, respectively, higher levels in red than in white muscle tissue, while the ratio of GSSG/GSH showed no differences. These characteristics may be due to an adaptive mechanism related to the 48% higher baseline level of TBARS in red muscle tissue. Immediately after 4 h of tourniquet-ischemia GSH, GSSG, and TBARS were increased (16%, 32%, 45% in white muscle; 19%, 49%, and 42% in red muscle, respectively), whereas the GSSG/GSH ratio remained unchanged. During the subsequent reperfusion period, GSH decreased within 2 h by 39% in white and 89% in red muscle to a minimal level of 5 mmol/g protein in both types of muscle. No recovery from the depletion was observed up to 12 h of reperfusion. The GSH decrease was parallelled by a marked increase of the GSSG/GSH ratio (150% in white and 450% in red muscle) and followed by about 150% increase in TBARS in both muscle types. This suggests that the increase in damaging TBARS is a secondary event after depletion of cellular antioxidants. Treatment of the animals during the reperfusion period with methyl-prednisolone, deferoxamine, or superoxide dismutase and catalase did not prevent the GSH decrease, but were effective in reducing the GSSG/GSH ratio to near normal and reducing the TBARS increase by about 50%.

Topics: Animals; Catalase; Deferoxamine; Glutathione; Glutathione Disulfide; Lipid Peroxidation; Male; Methylprednisolone; Muscles; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxide Dismutase; Thiobarbiturates; Tissue Distribution

Conjugated dienes (CD) are putative chemical imprints of oxyradical damage. Employing a highly selective assay for dienes based on their condensation with 14C-tetracyanoethylene (14C-TCNE), and a 14C-TCNE reagent with 60 times higher specific radioactivity than that used by Waller and Recknagel (1978), we have described the profile of phospholipid CD during global ischemia and reperfusion of the rat liver. During 70 min of ischemia, the hepatic CD appeared to increase moderately, but not statistically significantly, relative to that in sham-operated controls (with mean CD = 0.0397 +/- 0.0040 nmoles CD/nmole phosphate, for n = 7). In subsequent reperfusion, CD increased 2.6-3.3 fold higher than in sham controls during the first 10-15 min, declining thereafter to ischemia-like levels by 30 min of reflow. Our data demonstrate that oxyradicals are generated mostly during reperfusion of the post-ischemic rat liver, and that the refined TCNE method can quantitate tissue CD sensitively and relatively specifically.

Topics: Alkenes; Analysis of Variance; Animals; Calibration; Ethylenes; Free Radicals; Kinetics; Lipid Peroxidation; Liver; Male; Methods; Molecular Structure; Nitriles; Phospholipids; Rats; Rats, Inbred Strains; Reperfusion Injury; Sensitivity and Specificity; Thiobarbiturates

Reperfusion of rat kidney submitted to temporal ischaemia induces a decrease in glutathione content. Lipid peroxidation is not detected in kidney homogenates but microsomes obtained after periods of reperfusion longer than 60 minutes show increased malondialdehyde values correlated with high oxygen consumption and superoxide free radical generation. Microsomes obtained from kidneys submitted to 15 or 60 minutes of reperfusion are resistant to NADPH-induced lipid peroxidation but after 120 minutes of reperfusion an increased lipid peroxidative response is observed. Although the mechanism of the protection found in microsomes against the induction of oxidative stress in the first 60 minutes of reperfusion is unknown, it is postulated that this subcellular fraction plays an important role in the oxidative stress observed after longer periods of reperfusion.

Topics: Animals; Free Radicals; Glutathione; Ischemia; Kidney; Kinetics; Lipid Peroxidation; Male; Microsomes; NADP; Oxidation-Reduction; Oxygen; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxides; Thiobarbiturates

Reactive oxygen species are a major cause of damage occurring in ischemic tissue after reperfusion. During reperfusion transitional metals such as iron are required for reactive oxygen species to mediate their major toxic effects. Xanthine oxidase is an important source of reactive oxygen species during ischemia-reperfusion injury, but not in all organs or species. Because cytochrome P-450 enzymes are an important pulmonary source of superoxide anion (O2-.) generation under basal conditions and during hyperoxia, and provide iron catalysts necessary for hydroxyl radical (.OH) formation and propagation of lipid peroxidation, we postulated that cytochrome P-450 might have a potential role in mediating ischemia-reperfusion injury. In this report, we explored the role of cytochrome P-450 enzymes in a rabbit model of reperfusion lung injury. The P-450 inhibitors 8-methoxypsoralen, piperonyl butoxide, and cimetidine markedly decreased lung edema from transvascular fluid flux. Cimetidine prevented the reperfusion-related increase in lung microvascular permeability, as measured by movement of 125I-albumin from the vascular space into lung water and alveolar fluid. P-450 inhibitors also prevented the increase in lung tissue levels of thiobarbituric acid reactive products in the model. P-450 inhibitors did not block enhanced O2-. generation by ischemic reperfused lungs, measured by in vivo reduction of succinylated ferricytochrome c in lung perfusate, but did prevent the increase in non-protein-bound low molecular weight chelates of iron after reperfusion. Thus, cytochrome P-450 enzymes are not likely a major source of enhanced O2-. generation, but serve as an important source of iron in mediating oxidant injury to the rabbit lung during reperfusion. These results suggest an important role of cytochrome P-450 in reperfusion injury to the lung and suggest potential new therapies for the disorder.

Topics: Animals; Capillary Permeability; Cimetidine; Cytochrome P-450 Enzyme System; Iron; Ischemia; Lung; Methoxsalen; Piperonyl Butoxide; Rabbits; Reperfusion Injury; Superoxides; Thiobarbiturates

In this study we have examined the effect of propionyl-L-carnitine (PC) on rat spinal cord ischaemia and post-ischaemic reperfusion injury by evaluating two lipid peroxidation indices, thiobarbituric acid reactive substances (TBARS) and diene conjugation, before and after the addition of an ADP-Fe+2 complex to spinal cord homogenates. Aerobic, ischaemic, and post ischaemic reperfusion rat spinal cord homogenates from PC treated and untreated animals did not show any statistically significant difference in their TBARS and conjugated diene content. The addition of the ADP-Fe+2 complex to these homogenates resulted in an increased production of both the lipid peroxidation indices, though the magnitude of such formation was related to the type of experimental intervention. The post-ischaemic reperfusion samples of untreated rats showed the highest TBARS and conjugated diene content, while ischaemic samples in either treated and untreated rats did not show any statistically significant difference with respect to the aerobic samples. The post-ischaemic reperfusion samples of treated rats showed a statistically significant decrease of TBARS and conjugated diene production in comparison to the untreated samples. In addition, PC was also able to partially inhibit TBARS and conjugated diene formation in linoleic acid micelles exposed to hemoglobin, though it did not protect albumin fragmentation from the irradiation of water with an X-ray source.

Topics: Animals; Carnitine; Free Radicals; In Vitro Techniques; Ischemia; Lipid Peroxidation; Male; Rats; Rats, Inbred Strains; Reperfusion Injury; Spinal Cord; Thiobarbiturates

Free radicals in the small intestine were quantified by using an electron spin resonance spectrometer, and the amounts of TBA (thiobarbituric acid) reactants in arterial plasma, portal venous plasma and intestinal tissue were determined at the several stages. The effects of allopurinol, alpha-tocopherol, the simultaneous occlusion of superior mesenteric artery or the porto-jugular venous bypass, with the temporary occlusion of the portal vein, were also investigated. 1) Free radical concentration (mostly, semiquinones of CoQ and/or flavin in mitochondria) decreased with portal vein occlusion but showed a temporary increase at 10 sec after reperfusion. Allopurinol suppressed such temporary increase. 2) TBA reactants increased with the temporary occlusion of the portal vein. TBA reactants decreased during the portal vein occlusion with alpha-tocopherol and during reperfusion with allopurinol. Lipid peroxidation in the small intestine was also diminished by using the methods of simultaneous occlusion of the superior mesenteric artery or the porto-jugular venous bypass. In conclusion, there may be three sources for the generation of superoxide: the xanthine oxidase system, semiquinone radicals and paramagnetic metal irons. They may induce lipid a peroxidation, which accelerates the injury on the small intestine, in acute portal vein occlusion and the following restoration of portal vein flow in rats.

Topics: Allopurinol; Animals; Constriction; Electron Spin Resonance Spectroscopy; Free Radicals; Intestine, Small; Lipid Peroxidation; Male; Portal Vein; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxides; Thiobarbiturates; Vitamin E

Ischemia and reperfusion are of the greatest importance in the pathology of many diseases. We investigated the roles of oxygen-derived free radicals and lipid peroxidation in gastric mucosal injury, such as spotty and linear hemorrhagic erosions, induced in rats by ischemia-reperfusion. The gastric mucosal injury and the increase in thiobarbituric acid (TBA) reactants in the gastric mucosa induced by ischemia-reperfusion were significantly inhibited by treatment with SOD and catalase. These results suggest that oxygen-derived free radicals and lipid peroxidation play important roles in the pathogenesis of acute gastric mucosal lesions induced by ischemia-reperfusion.

Topics: Animals; Catalase; Free Radicals; Gastric Mucosa; Lipid Peroxides; Male; Oxygen; Rats; Rats, Inbred Strains; Reperfusion Injury; Superoxide Dismutase; Thiobarbiturates