4-hydroxy-2-nonenal and Reperfusion-Injury

Aldehyde dehydrogenase 2 (ALDH2) is best known for its critical detoxifying role in liver alcohol metabolism. However, ALDH2 dysfunction is also involved in a wide range of human pathophysiological situations and is associated with complications such as cardiovascular diseases, diabetes mellitus, neurodegenerative diseases and aging. A growing body of research has shown that ALDH2 provides important protection against oxidative stress and the subsequent loading of toxic aldehydes such as 4-hydroxy-2-nonenal and adducts that occur in human diseases, including ischemia reperfusion injury (IRI). There is increasing evidence of its role in IRI pathophysiology in organs such as heart, brain, small intestine and kidney; however, surprisingly few studies have been carried out in the liver, where ALDH2 is found in abundance. This study reviews the role of ALDH2 in modulating the pathways involved in the pathophysiology of IRI associated with oxidative stress, autophagy and apoptosis. Special emphasis is placed on the role of ALDH2 in different organs, on therapeutic "preconditioning" strategies, and on the use of ALDH2 agonists such as Alda-1, which may become a useful therapeutic tool for preventing the deleterious effects of IRI in organ transplantation.

Topics: Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Animals; Apoptosis; Autophagy; Benzamides; Benzodioxoles; Enzyme Activators; Humans; Lipid Peroxides; Liver; Metabolic Clearance Rate; Organ Transplantation; Oxidative Stress; Reactive Oxygen Species; Reperfusion Injury

Reactive oxygen intermediates (ROI) and other pro-oxidant agents are known to elicit, in vivo and in vitro, oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids (i.e, lipid peroxidation). This leads to the formation of a complex mixture of aldehydic end-products, including malonyldialdehyde (MDA), 4-hydroxy-2,3-nonenal (HNE), and other 4-hydroxy-2,3-alkenals (HAKs) of different chain length. These aldehydic molecules have been considered originally as ultimate mediators of toxic effects elicited by oxidative stress occurring in biological material. Experimental and clinical evidence coming from different laboratories now suggests that HNE and HAKs can also act as bioactive molecules in either physiological and pathological conditions. These aldehydic compounds can affect and modulate, at very low and nontoxic concentrations, several cell functions, including signal transduction, gene expression, cell proliferation, and, more generally, the response of the target cell(s). In this review article, we would like to offer an up-to-date review on this particular aspect of oxidative stress--dependent modulation of cellular functions-as well as to offer comments on the related pathophysiological implications, with special reference to human conditions of disease.

Topics: Aldehydes; Arteriosclerosis; Chemotactic Factors; Chronic Disease; Humans; Inflammation; Liver Diseases; Nervous System Diseases; Oxidative Stress; Proteins; Reperfusion Injury; Signal Transduction

Ischemia-reperfusion injury (IRI) is harmful to patients following kidney transplantation. Hypothermic machine perfusion (HMP) can be adopted to preserve grafts and reduce consequential injury. We hypothesized that aldehyde dehydrogenase 2 (ALDH2) partly mitigates kidney IRI via regulating excessive autophagy in HMP.. The rabbits were assigned to 5 groups: Normal, HMP, HMP + Alda-1, HMP + CYA and cold storage (CS). After the rabbit autologous kidney transplantation, renal pathology and function were evaluated by histological analysis, glomerular related proteins (desmin, nephrin), tubular injury factors (NGAL, Ki67), serum creatinine (Cr) and blood urea nitrogen (BUN). Oxidative stress molecular Malondialdehyde (MDA) and superoxide dismutase (SOD2) expression, as well as inflammatory cytokines (TNF-α, IL-6, IL-10) were assessed by immunohistochemistry. The expression of LC3, p62, ALDH2, p-Akt, mTOR, PTEN, p-PTEN, and 4-HNE were measured by immunohistochemistry, RT-PCR, Western blot analysis or ELISA.. HMP was more effective than CS for kidney preservation, with p- ALDH2 expressed in greater quantities in HMP. The results of kidney pathology and function in HMP + Alda-1 were the best. The MDA & SOD2 and the Vyacheslav score were improved in HMP + CYA. ALDH2 reduced 4-HNE-induced oxidative stress, inflammatory infiltration, the expression of LC3, p62 and inhibited autophagy accompanied by activation of p-Akt and mTOR via p-PTEN/PTEN.. Akt-mTOR autophagy pathway is a novel target for ALDH2 to reduce renal IRI partly by inhibition of 4-HNE in HMP, then protecting the donated kidney received after cardiac death (DCD).

Topics: Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Animals; Autophagy; Creatinine; Cytokines; Hypothermia, Induced; Kidney; Kidney Transplantation; Male; Oxidative Stress; Proto-Oncogene Proteins c-akt; Rabbits; Reperfusion Injury; TOR Serine-Threonine Kinases

Hepatic ischemia/reperfusion injury (HIRI) is a complex pathophysiological process that often leads to poor clinical prognosis. Clinically, the effective means to alleviate HIRI are limited. The aim of the present study was to investigate whether Alda‑1, an activator of mitochondrial aldehyde dehydrogenase 2 (ALDH2), had a protective effect on HIRI and to investigate the mechanisms underlying this protective effect. Sprague‑Dawley rats were treated with Alda‑1 or Daidzin, an ALDH2 inhibitor, 30 min before partial (70%) warm liver ischemia to induce HIRI. The 48 rats were randomly divided into four groups: Sham, ischemia injury (IR), IR‑Alda‑1, and IR‑Daidzin. After 6 and 24 h of reperfusion, serum and liver tissue samples were collected and stored for further experiments. Alanine aminotransferase, aspartate aminotransferase and hematoxylin & eosin staining was used to evaluate the liver damage. Western blotting and reverse transcription‑quantitative PCR were used to detect the expression of related proteins and mRNA. TUNEL staining was used to observe the apoptosis of liver cells. Transmission electron microscopy was used to detect the mitochondrial injuries. Alda‑1 pretreatment ameliorated the HIRI‑induced damage to the liver function and reduced histological lesions. Alda‑1 also increased ALDH2 activity after HIRI. Moreover, the pretreatment with Alda‑1 reduced the accumulation of toxic aldehyde 4‑hydroxy‑2‑nonenal, decreased the production of reactive oxygen species and malondialdehyde, reversed the damage to the liver mitochondria, attenuated hepatocyte apoptosis and inhibited the HIRI‑induced inflammatory response, including high‑mobility group box 1/toll‑like receptor 4 signaling. Alda‑1 also induced autophagy by upregulating autophagy‑related 7 and Rab7 increasing the microtubule associated protein 1 light chain 3 αII/I ratio and inhibiting p62 expression. ALDH2‑induced autophagy was dependent on the activation of the AKT/mammalian target of rapamycin (mTOR) and AMP‑activated protein kinase (AMPK) signaling pathways. In conclusion, the findings of the present study suggested that Alda‑1 may protect the liver against HIRI‑induced damage, including hepatic enzyme injury, acetaldehyde accumulation, oxidative stress, hepatocyte apoptosis and inflammation. Alda‑1 may confer this protection by inducing autophagy through the AKT/mTOR and AMPK signaling pathways. Therefore, ALDH2 could represent a potential pharmacological target in the clinical treatment

Topics: Aldehydes; Animals; Autophagy; Benzamides; Benzodioxoles; Disease Models, Animal; Gene Expression Regulation; Liver Diseases; Liver Function Tests; Male; Oxidative Stress; Random Allocation; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

Recombinant thrombomodulin (rTM) is a novel anticoagulant and anti-inflammatory agent that inhibits secretion of high-mobility group box 1 (HMGB1) from liver. We evaluated the protective effects of rTM on hepatic ischemia-reperfusion injury in rats. Ischemia was induced by clamping the portal vein and hepatic artery of left lateral and median lobes of the liver. At 30 min before ischemia and at 6 h after reperfusion, 0.3 ml of saline (IR group) or 0.3 ml of saline containing 6 mg/kg body weight of rTM (IR-rTM group) was injected into the liver through inferior vena cava or caudate vein. Blood flow was restored at 60 min of ischemia. Blood was collected 30 min prior to induction of ischemia and before restoration of blood flow, and at 6, 12, and 24 h after reperfusion. All the animals were euthanized at 24 h after reperfusion and the livers were harvested and subjected to biochemical and pathological evaluations. Serum levels of ALT, AST, and HMGB1 were significantly lower after reperfusion in the IR-rTM group compared to IR group. Marked hepatic necrosis was present in the IR group, while necrosis was almost absent in IR-rTM group. Treatment with rTM significantly reduced the expression of TNF-α and formation of 4-hydroxynonenal in the IR-rTM group compared to IR group. The results of the present study indicate that rTM could be used as a potent therapeutic agent to prevent IR-induced hepatic injury and the related adverse events.

Topics: Alanine Transaminase; Aldehydes; Animals; Aspartate Aminotransferases; HMGB1 Protein; Liver; Male; Malondialdehyde; Rats; Rats, Wistar; Recombinant Proteins; Reperfusion Injury; Thrombomodulin; Tumor Necrosis Factor-alpha

Ischemia-reperfusion injuries produce reactive oxygen species that promote the peroxide lipid oxidation process resulting in the production of an endogenic lipid peroxide, 4-hydroxy-trans-2-nonenal (4-HNE), a highly cytotoxic aldehyde that induces cell death. We synthesized a novel 4-HNE scavenger - a carnosine-hydrazide derivative, l-carnosine hydrazide (CNN) - and examined its neuroprotective effect in a model of transient ischemia. PC-12 cells were pre-incubated with various doses (0-50 mmol/L) of CNN for 30 min, followed by incubation with 4-HNE (250 μM). An MTT assay was performed 24 h later to examine cell survival. Transient ischemia was induced by bilateral common carotid artery occlusion (BCCO) in the Mongolian gerbil. Animals were assigned to sham-operated (n = 6), placebo-treated (n = 12), CNN pre-treated (20 mg/kg; n = 12), CNN post-treated (100 mg/kg; n = 11), and histidyl hydrazide (a previously known 4-HNE scavenger) post-treated (100 mg/kg; n = 7) groups. Heat shock protein 70 immunoreactivity in the hippocampal CA1 region was evaluated 24 h later, while delayed neuronal death using 4-HNE staining was evaluated 7 days later. Pre-incubation with 30 mmol/L CNN completely inhibited 4-HNE-induced cell toxicity. CNN prevented delayed neuronal death by >60% in the pre-treated group (p < 0.001) and by >40% in the post-treated group (p < 0.01). Histidyl hydrazide post-treatment elicited no protective effect. CNN pre-treatment resulted in high heat shock protein 70 and low 4-HNE immunoreactivity in CA1 pyramidal neurons. Higher 4-HNE immunoreactivity was also found in the placebo-treated animals than in the CNN pre-treated animals. Our novel compound, CNN, elicited highly effective 4-HNE scavenging activity in vitro. Furthermore, CNN administration both pre- and post-BCCO remarkably reduced delayed neuronal death in the hippocampal CA1 region via its induction of heat shock protein 70 and scavenging of 4-HNE.

Topics: Aldehydes; Animals; CA1 Region, Hippocampal; Carnosine; Cell Death; Gerbillinae; HSP70 Heat-Shock Proteins; Hydrazines; Ischemic Attack, Transient; Neurons; Neuroprotective Agents; PC12 Cells; Rats; Reperfusion Injury

Previous studies have proved that activation of aldehyde dehydrogenase two (ALDH2) can attenuate oxidative stress through clearance of cytotoxic aldehydes, and can protect against cardiac, cerebral, and lung ischemia/reperfusion (I/R) injuries. In this study, we investigated the effects of the ALDH2 activator Alda-1 on hepatic I/R injury. Partial warm ischemia was performed in the left and middle hepatic lobes of Sprague-Dawley rats for 1 h, followed by 6 h of reperfusion. Rats received either Alda-1 or vehicle by intravenous injection 30 min before ischemia. Blood and tissue samples of the rats were collected after 6-h reperfusion. Histological injury, proinflammatory cytokines, reactive oxygen species (ROS), cellular apoptosis, ALDH2 expression and activity, 4-hydroxy-trans-2-nonenal (4-HNE) and malondialdehyde (MDA) were measured. BRL-3A hepatocytes were subjected to hypoxia/reoxygenation (H/R). Cell viability, ROS, and mitochondrial membrane potential were determined. Pretreatment with Alda-1 significantly alleviated I/R-induced elevations of alanine aminotransferase and aspartate amino transferase, and significantly blunted the pathological injury of the liver. Moreover, Alda-1 significantly inhibited ROS and proinflammatory cytokines production, 4-HNE and MDA accumulation, and apoptosis. Increased ALDH2 activity was found after Alda-1 administration. No significant changes in ALDH2 expression were observed after I/R. ROS was also higher in H/R cells than in control cells, which was aggravated upon treatment with 4-HNE, and reduced by Alda-1 treatment. Cell viability and mitochondrial membrane potential were inhibited in H/R cells, which was attenuated upon Alda-1 treatment. Activation of ALDH2 by Alda-1 attenuates hepatic I/R injury via clearance of cytotoxic aldehydes.

Topics: Alanine Transaminase; Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Animals; Antioxidants; Apoptosis; Aspartate Aminotransferases; Benzamides; Benzodioxoles; Cell Line; Enzyme Activators; Gene Expression; Hepatocytes; Injections, Intravenous; Liver; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

BACKGROUND Revascularization is a successful therapeutic strategy for myocardial infarction. However, restoring coronary blood flow can lead to ischemia-reperfusion (I/R) injury. Low-dose 4-hydroxy-2-nonenal (HNE) therapy appears to play a key role in myocardial tolerance to I/R injury. We hypothesized that the positive effects of HNE on myocardial I/R injury may be UCP3-dependent. MATERIAL AND METHODS Adult male wild-type (WT) or UCP3 knockout (UCP3-/-) mice were pre-treated with the UCP inhibitor genipin or saline 1 h before ischemia and underwent 30-min coronary artery ligation followed by 24-h reperfusion. Mice were treated with intravenous HNE (4 mg/kg) or saline 5 min before reperfusion. Echocardiography was conducted to measure left ventricular end-diastolic posterior wall thickness (LVPWd), end-diastolic diameter (LVEDD), and fractional shortening (FS). Infarct size was measured by TTC staining. qRT-PCR and Western blotting were used to assess the expression of UCP3, UCP2, and the apoptosis markers cytochrome C and cleaved caspase-3. RESULTS HNE improved survival at 24 h post-MI in wild-type mice (p<0.05) but not in UCP3-/- mice. HNE preserved LVEDD and FS in WT mice (p<0.05) but not in UCP3-/- mice. HNE reduced infarct size in WT mice (p<0.05) but not in UCP3-/- mice. HNE upregulated UCP3 expression (p<0.05) but did not affect UCP2 expression. HNE reduced apoptosis marker expression in WT mice (p<0.05) but not in UCP3-/- mice. HNE's positive effects were abrogated by genipin in an UCP3-dependent manner. CONCLUSIONS Low-dose HNE reperfusion therapy attenuates murine myocardial I/R injury in an UCP3-dependent manner. These effects are abrogated by genipin in an UCP3-dependent manner.

Topics: Aldehydes; Animals; Apoptosis; Coronary Vessels; Heart; Iridoids; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardial Infarction; Myocardial Reperfusion; Myocardial Reperfusion Injury; Myocardium; Reperfusion Injury; Uncoupling Protein 3

Ischemic renal injury is a complex syndrome; multiple cellular abnormalities cause accelerating cycles of inflammation, cellular damage, and sustained local ischemia. There is no single therapy that effectively resolves the renal damage after ischemia. However, infusions of normal adult rat renal cells have been a successful therapy in several rat renal failure models. The sustained broad renal benefit achieved by relatively few donor cells led to the hypothesis that extracellular vesicles (EV, largely exosomes) derived from these cells are the therapeutic effector

Topics: Acute Kidney Injury; Aldehydes; Animals; Cell Communication; Disease Models, Animal; Exosomes; Extracellular Vesicles; Female; Gene Expression Profiling; Genotype; Hypoxia; Kidney; Kidney Tubules; Microcirculation; Neutrophils; Phenotype; Rats; Rats, Sprague-Dawley; Renal Insufficiency; Reperfusion Injury; RNA, Messenger; Time Factors

Complex regional pain syndrome type 1 (CRPS1) may be evoked by ischemia/reperfusion, eliciting acute and chronic pain that is difficult to treat. Despite this, the underlying mechanism of CRPS1 has not been fully elucidated. Therefore, the goal of this study is to evaluate the involvement of inflammation, oxidative stress, and the transient receptor potential ankyrin 1 (TRPA1) channel, a chemosensor of inflammation and oxidative substances, in an animal model of chronic post-ischemia pain (CPIP). Male Wistar rats were subjected to 3 h hind paw ischemia/reperfusion (CPIP model). Different parameters of nociception, inflammation, ischemia, and oxidative stress were evaluated at 1 (acute) and 14 (chronic) days after CPIP. The effect of a TRPA1 antagonist and the TRPA1 immunoreactivity were also observed after CPIP. In the CPIP acute phase, we observed mechanical and cold allodynia; increased levels of tumor necrosis factor-α (hind paw), ischemia-modified albumin (IMA) (serum), protein carbonyl (hind paw and spinal cord), lactate (serum), and 4-hydroxy-2-nonenal (4-HNE, hind paw and spinal cord); and higher myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGase) activities (hind paw). In the CPIP chronic phase, we detected mechanical and cold allodynia and increased levels of IMA (serum), protein carbonyl (hind paw and spinal cord), and 4-HNE (hind paw and spinal cord). TRPA1 antagonism reduced mechanical and cold allodynia 1 and 14 days after CPIP, but no change in TRPA1 immunoreactivity was observed. Different mechanisms underlie acute (inflammation and oxidative stress) and chronic (oxidative stress) phases of CPIP. TRPA1 activation may be relevant for CRPS1/CPIP-induced acute and chronic pain.

Topics: Acetylglucosaminidase; Acute Pain; Aldehydes; Animals; Chronic Pain; Cold Temperature; Hindlimb; Hyperalgesia; Lactic Acid; Male; Nociception; Oxidative Stress; Peroxidase; Protein Carbonylation; Rats; Rats, Wistar; Reflex Sympathetic Dystrophy; Reperfusion Injury; Serum Albumin; TRPA1 Cation Channel; TRPC Cation Channels; Tumor Necrosis Factor-alpha

Excessive oxidative stress is a main cause of lung ischemia-reperfusion injury, which often results in respiratory insufficiency after open-heart surgery for a cardiopulmonary bypass. Previous studies demonstrate that the activation of aldehyde dehydrogenase-2 could significantly reduce the oxidative stress mediated by toxic aldehydes and attenuate cardiac and cerebral ischemia-reperfusion injury. However, both the involvement of aldehydes and the protective effect of the aldehyde dehydrogenase-2 agonist, Alda-1, in lung ischemia-reperfusion injury remain unknown.. Prospective laboratory and animal investigation were conducted.. State Key Laboratory of Cardiovascular Disease.. Primary human pulmonary alveolar epithelial cells, human pulmonary microvascular endothelial cells, and Sprague-Dawley rats.. A hypoxia/reoxygenation cell-culture model of human pulmonary alveolar epithelial cell, human pulmonary microvascular endothelial cell, and an isolated-perfused lung model were applied to mimic lung ischemia-reperfusion injury. We evaluated the effects of Alda-1 on aldehyde dehydrogenase-2 quantity and activity, on aldehyde levels and pulmonary protection.. We have demonstrated that ischemia-reperfusion-induced pulmonary injury concomitantly induced aldehydes accumulation in human pulmonary alveolar epithelial cells and lung tissues, but not in human pulmonary microvascular endothelial cells. Moreover, Alda-1 pretreatment significantly elevated aldehyde dehydrogenase-2 activity, increased surfactant-associated protein C, and attenuated elevation of 4-hydroxy-2-nonenal, apoptosis, intercellular adhesion molecule-1, inflammatory response, and the permeability of pulmonary alveolar capillary barrier, thus alleviated injury.. Our study indicates that the accumulation of 4-hydroxy-2-nonenal plays an important role in lung ischemia-reperfusion injury. Alda-1 pretreatment can attenuate lung ischemia-reperfusion injury, possibly through the activation of aldehyde dehydrogenase-2, which in turn removes 4-hydroxy-2-nonenal in human pulmonary alveolar epithelial cells. Alda-1 pretreatment has clinical implications to protect lungs during cardiopulmonary bypass.

Topics: Aldehyde Dehydrogenase, Mitochondrial; Aldehydes; Alveolar Epithelial Cells; Animals; Benzamides; Benzodioxoles; Cells, Cultured; Humans; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Ischemia-reperfusion (IR) injury is a major clinical problem and is associated with numerous adverse effects. GGsTop [2-amino-4{[3-(carboxymethyl)phenyl](methyl)phosphono}butanoic acid] is a highly specific and irreversible γ-glutamyl transpeptidase (γ-GT) inhibitor. We studied the protective effects of GGsTop on IR-induced hepatic injury in rats. Ischemia was induced by clamping the portal vein and hepatic artery of left lateral and median lobes of the liver. Before clamping, saline (IR group) or saline containing 1 mg/kg body wt of GGsTop (IR-GGsTop group) was injected into the liver through the inferior vena cava. At 90 min of ischemia, blood flow was restored. Blood was collected before induction of ischemia and prior to restoration of blood flow and at 12, 24, and 48 h after reperfusion. All the animals were euthanized at 48 h after reperfusion and the livers were harvested. Serum levels of alanine transaminase, aspartate transaminase, and γ-GT were significantly lower after reperfusion in the IR-GGsTop group compared with the IR group. Massive hepatic necrosis was present in the IR group, while only few necroses were present in the IR-GGsTop group. Treatment with GGsTop increased hepatic GSH content, which was significantly reduced in the IR group. Furthermore, GGsTop prevented increase of hepatic γ-GT, malondialdehyde, 4-hydroxynonenal, and TNF-α while all these molecules significantly increased in the IR group. In conclusion, treatment with GGsTop increased glutathione levels and prevented formation of free radicals in the hepatic tissue that led to decreased IR-induced liver injury. GGsTop could be used as a pharmacological agent to prevent IR-induced liver injury and the related adverse events.

Topics: Alanine Transaminase; Aldehydes; Aminobutyrates; Animals; Aspartate Aminotransferases; Cytoprotection; Disease Models, Animal; Enzyme Inhibitors; gamma-Glutamyltransferase; Glutathione; Interleukin-1beta; Liver; Liver Diseases; Male; Malondialdehyde; Necrosis; Organophosphonates; Oxidative Stress; Rats, Wistar; Reperfusion Injury; Tumor Necrosis Factor-alpha

Transient ischemia-reperfusion in the hand and foot elicits spontaneous dysesthesia. However, the mechanisms by which this occurs are not completely understood. The objectives of this study were to examine peripheral neural activity related to spontaneous dysesthesia in a mouse model of hind-paw transient ischemic-reperfusion and to investigate the involvement of oxidative stress in this neural activity. The femoral artery and vein were interrupted for 10min using tourniquet pressure, before the tourniquet was removed to allow reperfusion of the hind paw. Neural activity in the saphenous nerve was recorded during both ischemia and reperfusion. In both the ischemic phase and the reperfusion phase, the frequency of saphenous nerve firing was significantly increased compared to baseline. The antioxidant agent N-acetyl-l-cysteine inhibited significantly the firing of the saphenous nerve in both the maximum and minimum activity periods during ischemia, and in the maximum activity state after reperfusion percentage inhibition being approximately 68%, 60%, and 58%, respectively. In the reperfusion phase, the production of 4-hydroxy-2-noneal, a major product of endogenous lipid peroxidation, was significantly increased in the plantar skin, and this was inhibited by N-acetyl-l-cysteine. In the ischemic phase, a similar trend was observed. These results suggest that an increase in peripheral nerve activity related to oxidative stress may be involved in the spontaneous dysesthesia induced by transient ischemia-reperfusion.

Topics: Action Potentials; Aldehydes; Animals; Disease Models, Animal; Hindlimb; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Paresthesia; Peripheral Nerves; Reperfusion Injury; Skin

Renal ischemia-reperfusion (I/R) is a major cause of acute renal failure. The mechanisms of I/R injury include endoplasmic reticulum (ER) stress, inflammatory responses, hypoxia, and generation of reactive oxygen species (ROS). CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) is involved in the ER stress signaling pathways. CHOP is a transcription factor and a major mediator of ER stress-induced apoptosis. However, the role of CHOP in renal I/R injury is still undefined. Here, we investigated whether CHOP could regulate I/R-induced renal injury using CHOP-knockout mice and cultured renal tubular cells as models.. In CHOP-knockout mice, loss of renal function induced by I/R was prevented. Renal proximal tubule damage was induced by I/R in wild-type mice; however, the degree of alteration was significantly less in CHOP-knockout mice. CHOP deficiency also decreased the I/R-induced activation of caspase-3 and -8, apoptosis, and lipid peroxidation, whereas the activity of endogenous antioxidants increased. In an in vitro I/R model, small interfering RNA targeting CHOP significantly reversed increases in H2O2 formation, inflammatory signals, and apoptotic signals, while enhancing the activity of endogenous antioxidants in renal tubular cells.. To the best of our knowledge, this is the first study which demonstrates that CHOP deficiency attenuates oxidative stress and I/R-induced acute renal injury both in vitro and in vivo.. These findings suggest that CHOP regulates not only apoptosis-related signaling but also ROS formation and inflammation in renal tubular cells during I/R. CHOP may play an important role in the pathophysiology of I/R-induced renal injury.

Topics: Aldehydes; Animals; Antioxidants; Apoptosis; Cell Hypoxia; Cell Line; Gene Knockdown Techniques; Glutathione; Ischemia; Kidney; Lipid Peroxidation; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Reactive Oxygen Species; Reperfusion Injury; RNA, Small Interfering; Transcription Factor CHOP

We demonstrated that 3-nitrotyrosine and 4-hydroxy-2-nonenal levels in mouse brain were elevated from 1 h until 8 h after global brain ischemia for 14 min induced with the 3-vessel occlusion model; this result indicates that ischemia reperfusion injury generated oxidative stress. Reactive oxygen species production was observed not only in the hippocampal region, but also in the cortical region. We further evaluated the neuroprotective effect of xanthine oxidoreductase inhibitors in the mouse 3-vessel occlusion model by analyzing changes in the expression of genes regulated by the transcription factor nuclear factor-kappa B (including pro-inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), matrix metalloproteinase-9 and intercellular adhesion molecules-1). Administration of allopurinol resulted in a statistically significant decrease in IL-1β and TNF-α mRNA expression, whereas febuxostat had no significant effect on expression of these genes; nevertheless, both inhibitors effectively reduced serum uric acid concentration. It is suggested that the neuroprotective effect of allopurinol is derived not from inhibition of reactive oxygen species production by xanthine oxidoreductase, but rather from a direct free-radical-scavenging effect.

Topics: Aldehydes; Allopurinol; Animals; Biomarkers; Brain; Brain Ischemia; Disease Models, Animal; Interleukin-1beta; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Neuroprotective Agents; NF-kappa B; Oxidative Stress; Reactive Oxygen Species; Reperfusion Injury; RNA, Messenger; Tumor Necrosis Factor-alpha; Tyrosine; Uric Acid; Xanthine Dehydrogenase

Despite successful revascularization, reperfusion after prolonged ischemia causes ischemia reperfusion (I/R) injury. Recruitment and activation of neutrophils is thought to be a key event causing I/R injury. We examined whether post-ischemic intra-arterial infusion of liposome-encapsulated hemoglobin (LEH), an artificial oxygen carrier without neutrophils, could reduce I/R injury in a rat transient middle cerebral artery occlusion (MCAO) model. Male Sprague-Dawley rats were subjected to 2-h MCAO and then were divided into three groups: (1) LEH group (n=7) infused with LEH (Hb concentration of 6g/dl, 10ml/kg/h) through the recanalized internal carotid artery for 2h, (2) vehicle group (n=8) infused with saline (10ml/kg/h) in the same manner as the LEH group, and (3) control group (n=9) subjected to recanalization only. After 24-h reperfusion, all rats were tested for neurological score and then sacrificed to examine infarct and edema volumes, myeloperoxidase (MPO) expression, matrix metalloproteinase-9 (MMP-9) expression and activity, and reactive oxygen species (ROS) production. Compared with the control group and the vehicle group, the LEH group showed a significantly better neurological score and significantly smaller infarct and edema volumes. MPO expression, MMP-9 expression and activity, and ROS production in the LEH group were also significantly lower than those in the control and vehicle groups. The results in the present study suggest that post-ischemic intra-arterial infusion of LEH can reduce I/R injury through reducing the effect of MMP-9, most likely produced by neutrophils. This therapeutic strategy may be a promising candidate to prevent I/R injury after thrombolysis and/or thromboectomy.

Topics: Aldehydes; Animals; Brain; Brain Ischemia; Carotid Artery, Internal; Edema; Hemoglobins; Humans; Infarction, Middle Cerebral Artery; Infusions, Intra-Arterial; Liposomes; Male; Matrix Metalloproteinase 9; Peroxidase; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Severity of Illness Index

Alpinia katsumadai (Zingiberaceae) has been identified by the National Plant Quarantine Service in Korea. The extract of Alpinia katsumadai seed (EAKS) has antioxidant activities.. We investigated the neuroprotective effects of EAKS on ischemic damage in the gerbil hippocampal CA1 region after transient cerebral ischemia.. The ethanol extract of EAKS was obtained by organic solvent, collected in Kangwon province (South Korea) and orally administered using a feeding needle once a day for one week before transient cerebral ischemia in gerbils.. We adapted oral administration of 25 and 50 mg/kg EAKS because there are no data about the absorption and metabolism of EKAS. We found a significant neuroprotection in the 50 mg/kg EAKS-treated ischemia group, not in the 25 mg/kg EAKS-treated ischemia group, at 4 days ischemia-reperfusion (I-R). In the 50 mg/kg EAKS-treated ischemia group, about 68% of pyramidal neurons in the CA1 region were immunostained with neuronal nuclei (NeuN) 4 days after I-R, compared to the vehicle-treated ischemia group. 8-Hydroxy-2'-deoxyguanosine (a marker for DNA damage) and 4-hydroxy-2-nonenal (a marker for lipid peroxidation) immunoreactivity in the CA1 region of the EAKS-treated ischemia group were not markedly changed compared to the vehicle-treated ischemia group. In addition, Cu,Zn- and Mn-SOD immunoreactivity in the CA1 region of the EAKS-treated ischemia group were increased compared to the vehicle-treated ischemia group.. Repeated supplements of EAKS could protect neurons against ischemic damage, showing that DNA damage and lipid peroxidation are attenuated and SODs are increased in the ischemic CA1 region.

Topics: Administration, Oral; Aldehydes; Alpinia; Animals; Antioxidants; Brain Ischemia; CA1 Region, Hippocampal; Cytoprotection; Disease Models, Animal; DNA Damage; Ethanol; Gerbillinae; Immunohistochemistry; Lipid Peroxidation; Male; Neuroprotective Agents; Oxidative Stress; Plant Extracts; Plants, Medicinal; Reperfusion Injury; Seeds; Solvents; Superoxide Dismutase; Time Factors

Cannabinoid CB(2) receptor activation has been reported to attenuate myocardial, cerebral and hepatic ischaemia-reperfusion (I/R) injury.. We have investigated the effects of a novel CB(2) receptor agonist ((1S,4R)-2-(2,6-dimethoxy-4-(2-methyloctan-2-yl)phenyl)-7,7-dimethylbicyclo[2.2.1]hept-2-en-1-yl)methanol (HU-910) on liver injury induced by 1 h of ischaemia followed by 2, 6 or 24 h of reperfusion, using a well-established mouse model of segmental hepatic I/R.. Displacement of [(3) H]CP55940 by HU-910 from specific binding sites in CHO cell membranes transfected with human CB(2) or CB(1) receptors (hCB(1/2) ) yielded K(i) values of 6 nM and 1.4 µM respectively. HU-910 inhibited forskolin-stimulated cyclic AMP production by hCB(2) CHO cells (EC(50) = 162 nM) and yielded EC(50) of 26.4 nM in [(35) S]GTPγS binding assays using hCB(2) expressing CHO membranes. HU-910 given before ischaemia significantly attenuated levels of I/R-induced hepatic pro-inflammatory chemokines (CCL3 and CXCL2), TNF-α, inter-cellular adhesion molecule-1, neutrophil infiltration, oxidative stress and cell death. Some of the beneficial effect of HU-910 also persisted when given at the beginning of the reperfusion or 1 h after the ischaemic episode. Furthermore, HU-910 attenuated the bacterial endotoxin-triggered TNF-α production in isolated Kupffer cells and expression of adhesion molecules in primary human liver sinusoidal endothelial cells stimulated with TNF-α. Pretreatment with a CB(2) receptor antagonist attenuated the protective effects of HU-910, while pretreatment with a CB(1) antagonist tended to enhance them.. HU-910 is a potent CB(2) receptor agonist which may exert protective effects in various diseases associated with inflammation and tissue injury.. This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.

Topics: Alanine Transaminase; Aldehydes; Animals; Apoptosis; Aspartate Aminotransferases; Bridged Bicyclo Compounds; Cell Death; Cell Line; CHO Cells; Cricetinae; Cytokines; DNA Fragmentation; Humans; Inflammation; Intercellular Adhesion Molecule-1; Liver; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Protective Agents; Receptor, Cannabinoid, CB2; Reperfusion Injury; RNA, Messenger

Activation of cannabinoid CB(2) receptors protects against various forms of ischaemia-reperfusion (I/R) injury. Δ(8) -Tetrahydrocannabivarin (Δ(8) -THCV) is a synthetic analogue of the plant cannabinoid Δ(9) -tetrahydrocannabivarin, which exhibits anti-inflammatory effects in rodents involving activation of CB(2) receptors. Here, we assessed effects of Δ(8) -THCV and its metabolite 11-OH-Δ(8) -THCV on CB(2) receptors and against hepatic I/R injury.. Effects in vitro were measured with human CB(2) receptors expressed in CHO cells. Hepatic I/R injury was assessed in mice with 1h ischaemia and 2, 6 or 24h reperfusion in vivo.. Displacement of [(3) H]CP55940 by Δ(8) -THCV or 11-OH-Δ(8) -THCV from specific binding sites in CHO cell membranes transfected with human CB(2) receptors (hCB(2) ) yielded K(i) values of 68.4 and 59.95 nM respectively. Δ(8) -THCV or 11-OH-Δ(8) -THCV inhibited forskolin-stimulated cAMP production by hCB(2) CHO cells (EC(50) = 12.95 and 14.3 nM respectively). Δ(8) -THCV, given before induction of I/R, attenuated hepatic injury (measured by serum alanine aminotransferase and aspartate aminotransferase levels), decreased tissue protein carbonyl adducts, 4-hydroxy-2-nonenal, the chemokines CCL3 and CXCL2,TNF-α, intercellular adhesion molecule 1 (CD54) mRNA levels, tissue neutrophil infiltration, caspase 3/7 activity and DNA fragmentation. Protective effects of Δ(8) -THCV against liver damage were still present when the compound was given at the beginning of reperfusion. Pretreatment with a CB(2) receptor antagonist attenuated the protective effects of Δ(8) -THCV, while a CB(1) antagonist tended to enhance it.. Δ(8) -THCV activated CB(2) receptors in vitro, and decreased tissue injury and inflammation in vivo, associated with I/R partly via CB(2) receptor activation.. This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.

Topics: Alanine Transaminase; Aldehydes; Animals; Apoptosis; Aspartate Aminotransferases; CHO Cells; Cricetinae; Cricetulus; Cytokines; DNA Fragmentation; Dronabinol; Humans; Inflammation; Liver; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Protective Agents; Receptor, Cannabinoid, CB2; Reperfusion Injury; RNA, Messenger

The synthesis, physico-chemical, and biological characterisation of a short series of carnosine amides bearing NO-donor nitrooxy functionalities are described. The NO-donor carnosine analogues and their des-NO derivatives display carnosine-like properties, differing from the lead for their high serum stability. The newly-synthesised compounds are able to complex Cu(2+) ions at physiological pH, displaying significant copper ion sequestering ability, and protect LDL from oxidation catalysed by Cu(2+) ions. All products show moderately-potent HNE quenching activity. The NO-donor compounds 7c-f relaxed rat aorta strips via an NO-dependent mechanism. In vivo evaluation of organ protection in a model of cerebral ischaemia/reperfusion injury, using the selected NO-donor 7e and its des-NO analogue 7a, showed that both derivatives protect from hypoxia-induced brain damage, at lower concentrations than carnosine; 7e also decreased serum TNF-α levels. This class of NO-donor carnosine amides is worthy of further study as potential tools for treating a wide range of chronic vascular and neurodegenerative diseases in which NO-bioavailability is reduced.

Topics: Aldehydes; Animals; Antioxidants; Carnosine; Chemical Phenomena; Chemistry Techniques, Synthetic; Copper; Drug Stability; Humans; Hydrophobic and Hydrophilic Interactions; In Vitro Techniques; Male; Nitric Oxide; Rats; Reperfusion Injury; Vasodilation

Radix Astragali has been commonly used as traditional herbal medicine in China for reinforcing vital energy, strengthening superficial resistance and promoting the discharge of pus and the growth of new tissue.. The present study was to investigate the neuroprotective effect of calycosin isolated from the roots of Radix Astragali on cerebral ischemic/reperfusion injury.. After 24h of reperfusion following ischemia for 2h induced by middle cerebral artery occlusion (MCAO), Sprague-Dawley rats were intragastrically administered different doses of calycosin (7.5, 15, 30 mg/kg, respectively). Neurological deficit, infarct volume, histopathology changes and some oxidative stress markers were evaluated after 24h of reperfusion.. Treatment with calycosin significantly ameliorated neurologic deficit and infarct volume after cerebral ischemia reperfusion. Calycosin also reduced the content of malondialdehyde (MDA), protein carbonyl and reactive oxygen species (ROS), and up-regulated the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in a dose-dependent manner. Moreover, calycosin can also inhibit the expression of 4-Hydroxy-2-nonenal (4-HNE).. These results suggest that calycosin has a neuroprotective effect against cerebral ischemia/reperfusion injury. The mechanism might be attributed to its antioxidant effects.

Topics: Aldehydes; Animals; Behavior, Animal; Brain; Catalase; Diagnostic Techniques, Neurological; Disease Models, Animal; Glutathione Peroxidase; Infarction, Middle Cerebral Artery; Isoflavones; Male; Malondialdehyde; Mitochondria; Movement; Neuroprotective Agents; Phytotherapy; Protein Carbonylation; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase

This study was designed to investigate if α-mangostin (α-M), a xanthone present in the pericarp of Garcinia mangostana L., was able to protect against reperfusion injury in Langendorff-reperfused hearts. It was observed that α-M maintains the cardiac mechanical work, diminishes the area of infarct, and prevents the decrease in cardiac ATP and phosphocreatine levels in the reperfused myocardium. The protective effect of this xanthone was associated with reduction of oxidative stress. α-M treatment prevented reperfusion injury-induced protein oxidation (protein carbonyl content), lipid peroxidation (malondialdehyde and 4-hydroxynonenal content), and diminution of glutathione content. In fact, after α-M treatment, the values in these parameters were comparable to those obtained in nonreperfused hearts. In summary, α-M induces a protective effect in postischemic heart associated to the prevention of oxidative stress secondary to reperfusion injury.

Topics: Aldehydes; Animals; Antioxidants; Garcinia mangostana; Glutathione; Heart; Lipid Peroxidation; Male; Malondialdehyde; Myocardium; Oxidative Stress; Phosphocreatine; Plant Extracts; Protective Agents; Rats; Rats, Wistar; Reperfusion Injury; Xanthones

Retinal ischemia-reperfusion (I/R) injury by transient elevation of intraocular pressure (IOP) is known to induce neuronal damage through the generation of reactive oxygen species. Study results have indicated that molecular hydrogen (H(2)) is an efficient antioxidant gas that selectively reduces the hydroxyl radical (*OH) and suppresses oxidative stress-induced injury in several organs. This study was conducted to explore the neuroprotective effect of H(2)-loaded eye drops on retinal I/R injury.. Retinal ischemia was induced in rats by raising IOP for 60 minutes. H(2)-loaded eye drops were prepared by dissolving H(2) gas into a saline to saturated level and administered to the ocular surface continuously during the ischemia and/or reperfusion periods. One day after I/R injury, apoptotic cells in the retina were quantified, and oxidative stress was evaluated by markers such as 4-hydroxynonenal and 8-hydroxy-2-deoxyguanosine. Seven days after I/R injury, retinal damage was quantified by measuring the thickness of the retina.. When H(2)-loaded eye drops were continuously administered, H(2) concentration in the vitreous body immediately increased and I/R-induced *OH level decreased. The drops reduced the number of retinal apoptotic and oxidative stress marker-positive cells and prevented retinal thinning with an accompanying activation of Müller glia, astrocytes, and microglia. The drops improved the recovery of retinal thickness by >70%.. H(2) has no known toxic effects on the human body. Thus, the results suggest that H(2)-loaded eye drops are a highly useful neuroprotective and antioxidative therapeutic treatment for acute retinal I/R injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Apoptosis; Biomarkers; Deoxyguanosine; Diffusion; Disease Models, Animal; Hydrogen; Hydroxyl Radical; Immunoenzyme Techniques; In Situ Nick-End Labeling; Male; Microscopy, Confocal; Neuroglia; Ophthalmic Solutions; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Retinal Diseases; Retinal Neurons; Vitreous Body

Reactive oxygen species (ROS) attack polyunsaturated fatty acids of the membrane and trigger lipid peroxidation, which results in the generation of alpha,beta-unsaturated aldehydes, such as 4-hydroxy-2-nonenal (4-HNE). There is compelling evidence that high concentrations of aldehydes are responsible for much of the damage elicited by cardiac ischemia-reperfusion injury, while sublethal concentrations of aldehydes stimulate stress resistance pathways, to achieve cardioprotection. We investigated the mechanism of cardioprotection mediated by 4-HNE. For cultured cardiomyocytes, 4-HNE was cytotoxic at higher concentrations (>or=20 microM) but had no appreciable cytotoxicity at lower concentrations. Notably, a sublethal concentration (5muM) of 4-HNE primed cardiomyocytes to become resistant to cytotoxic concentrations of 4-HNE. 4-HNE induced nuclear translocation of transcription factor NF-E2-related factor 2 (Nrf2), and enhanced the expression of gamma-glutamylcysteine ligase (GCL) and the core subunit of the Xc(-) high-affinity cystine transporter (xCT), thereby increasing 1.45-fold the intracellular GSH levels. Cardiomyocytes treated with either Nrf2-specific siRNA or the GCL inhibitor l-buthionine sulfoximine (BSO) were less tolerant to 4-HNE. Moreover, the cardioprotective effect of 4-HNE pretreatment against subsequent glucose-free anoxia followed by reoxygenation was completely abolished in these cells. Intravenous administration of 4-HNE (4 mg/kg) activated Nrf2 in the heart and increased the intramyocardial GSH content, and consequently improved the functional recovery of the left ventricle following ischemia-reperfusion in Langendorff-perfused hearts. This cardioprotective effect of 4-HNE was not observed for Nrf2-knockout mice. In summary, 4-HNE activates Nrf2-mediated gene expression and stimulates GSH biosynthesis, thereby conferring on cardiomyocytes protection against ischemia-reperfusion injury.

Topics: Aldehydes; Animals; Blotting, Western; Cell Death; Cells, Cultured; Glutathione; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocytes, Cardiac; NF-E2-Related Factor 2; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

Prolonged ischemia amplified iscehemia/reperfusion (IR) induced renal apoptosis and autophagy. We hypothesize that ischemic conditioning (IC) by a briefly intermittent reperfusion during a prolonged ischemic phase may ameliorate IR induced renal dysfunction. We evaluated the antioxidant/oxidant mechanism, autophagy and apoptosis in the uninephrectomized Wistar rats subjected to sham control, 4 stages of 15-min IC (I15 x 4), 2 stages of 30-min IC (I30 x 2), and total 60-min ischema (I60) in the kidney followed by 4 or 24 hours of reperfusion. By use of ATP assay, monitoring O2-. amounts, autophagy and apoptosis analysis of rat kidneys, I60 followed by 4 hours of reperfusion decreased renal ATP and enhanced reactive oxygen species (ROS) level and proapoptotic and autophagic mechanisms, including enhanced Bax/Bcl-2 ratio, cytochrome C release, active caspase 3, poly-(ADP-ribose)-polymerase (PARP) degradation fragments, microtubule-associated protein light chain 3 (LC3) and Beclin-1 expression and subsequently tubular apoptosis and autophagy associated with elevated blood urea nitrogen and creatinine level. I30 x 2, not I15 x 4 decreased ROS production and cytochrome C release, increased Manganese superoxide dismutase (MnSOD), Copper-Zn superoxide dismutase (CuZnSOD) and catalase expression and provided a more efficient protection than I60 against IR induced tubular apoptosis and autophagy and blood urea nitrogen and creatinine level. We conclude that 60-min renal ischemia enhanced renal tubular oxidative stress, proapoptosis and autophagy in the rat kidneys. Two stages of 30-min ischemia with 3-min reperfusion significantly preserved renal ATP content, increased antioxidant defense mechanisms and decreased ischemia/reperfusion enhanced renal tubular oxidative stress, cytosolic cytochrome C release, proapoptosis and autophagy in rat kidneys.

Topics: Aldehydes; Animals; Antioxidants; Apoptosis; Autophagy; Blood Urea Nitrogen; Creatinine; Cysteine Proteinase Inhibitors; Cytochromes c; Female; Ischemic Preconditioning; Isoenzymes; Kidney; NADPH Oxidases; Nephrectomy; Oxidative Stress; Peroxidase; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase

Retinal ischemia/reperfusion (I/R) injury results in the generation of reactive oxygen species (ROS). The aim of this study was to investigate whether delivery of the manganese superoxide dismutase gene (SOD2) or the catalase gene (CAT) could rescue the retinal vascular damage induced by I/R in mice.. I/R injury to the retina was induced in mice by elevating intraocular pressure for 2 hours, and reperfusion was established immediately afterward. One eye of each mouse was pretreated with plasmids encoding manganese superoxide dismutase or catalase complexed with cationic liposomes and delivered by intravitreous injection 48 hours before initiation of the procedure. Superoxide ion, hydrogen peroxide, and 4-hydroxynonenal (4-HNE) protein modifications were measured by fluorescence staining, immunohistochemistry, and Western blot analysis 1 day after the I/R injury. At 7 days after injury, retinal vascular cell apoptosis and acellular capillaries were quantitated.. Superoxide ion, hydrogen peroxide, and 4-HNE protein modifications increased at 24 hours after I/R injury. Administration of plasmids encoding SOD2 or CAT significantly reduced levels of superoxide ion, hydrogen peroxide, and 4-HNE. Retinal vascular cell apoptosis and acellular capillary numbers increased greatly by 7 days after the injury. Delivery of SOD2 or CAT inhibited the I/R-induced apoptosis of retinal vascular cell and retinal capillary degeneration.. Delivery of antioxidant genes inhibited I/R-induced retinal capillary degeneration, apoptosis of vascular cells, and ROS production, suggesting that antioxidant gene therapy might be a treatment for I/R-related disease.

Topics: Aldehydes; Animals; Blotting, Western; Capillaries; Catalase; Female; Gene Expression Regulation, Enzymologic; Gene Transfer Techniques; Hydrogen Peroxide; Immunohistochemistry; In Situ Nick-End Labeling; Liposomes; Mice; Mice, Inbred C57BL; Plasmids; Reactive Oxygen Species; Reperfusion Injury; Retinal Degeneration; Retinal Vessels; Spectrometry, Fluorescence; Superoxide Dismutase; Superoxides

The c-Jun N-terminal kinase (JNK) pathway enhances graft injury after liver transplantation (LT). We hypothesized that the JNK2 isoform promotes graft injury via the mitochondrial permeability transition (MPT). Livers of C57BL/6J (wild-type, WT) and JNK2 knockout (KO) mice were transplanted into WT recipients after 30 h of cold storage in UW solution. Injury after implantation was assessed by serum ALT, histological necrosis, TUNEL, Caspase 3 activity, 30-day survival, and cytochrome c and 4-hydroxynonenal immunostaining. Multiphoton microscopy after LT monitored mitochondrial membrane potential in vivo. After LT, ALT increased three times more in WT compared to KO (p < 0.05). Necrosis and TUNEL were more than two times greater in WT than KO (p < 0.05). Immunostaining showed a >80% decrease of mitochondrial cytochrome c release in KO compared to WT (p < 0.01). Lipid peroxidation was similarly decreased. Every KO graft but one survived longer than all WT grafts (p < 0.05, Kaplan-Meier). After LT, depolarization of mitochondria occurred in 73% of WT hepatocytes, which decreased to 28% in KO (p < 0.05). In conclusion, donor JNK2 promotes injury after mouse LT via the MPT. MPT inhibition using specific JNK2 inhibitors may be useful in protecting grafts against adverse outcomes from ischemia/reperfusion injury.

Topics: Alanine Transaminase; Aldehydes; Animals; Apoptosis; Caspase 3; Immunohistochemistry; Isoenzymes; Lipid Peroxidation; Liver Transplantation; Male; Membrane Potential, Mitochondrial; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Mitogen-Activated Protein Kinase 9; Necrosis; Permeability; Prospective Studies; Random Allocation; Reperfusion Injury; Transplants

The mechanisms of progression from fatty liver to steatohepatitis and cirrhosis are not well elucidated. Mitochondrial dysfunction represents a key factor in the progression of non-alcoholic steatohepatitis (NASH) as mitochondria are the main cellular site of fatty acid oxidation, ATP synthesis and reactive oxygen species (ROS) production.. (1) To evaluate the role of the uncoupling protein 2 in controlling mitochondrial proton leak and ROS production in NASH rats and humans; and (2) to assess the acute liver damage induced by ischaemia-reperfusion in rats with NASH.. Mitochondria were extracted from the livers of NASH humans and rats fed a methionine and choline deficient diet. Proton leak, H(2)O(2) synthesis, reduced glutathione/oxidised glutathione, 4-hydroxy-2-nonenal (HNE)-protein adducts, uncoupling protein-2 (UCP2) expression and ATP homeostasis were evaluated before and after ischaemia-reperfusion injury.. NASH mitochondria exhibited an increased rate of proton leak due to upregulation of UCP2. These results correlated with increased production of mitochondrial hydrogen peroxide and HNE-protein adducts, and decreased hepatic ATP content that was not dependent on mitochondrial ATPase dysfunction. The application of an ischaemia-reperfusion protocol to these livers strongly depleted hepatic ATP stores, significantly increased mitochondrial ROS production and impaired ATPase activity. Livers from patients with NASH exhibited UCP2 over-expression and mitochondrial oxidative stress.. Upregulation of UCP2 in human and rat NASH liver induces mitochondrial uncoupling, lowers the redox pressure on the mitochondrial respiratory chain and acts as a protective mechanism against damage progression but compromises the liver capacity to respond to additional acute energy demands, such as ischaemia-reperfusion. These findings suggest that UCP2-dependent mitochondria uncoupling is an important factor underlying events leading to NASH and cirrhosis.

Topics: Acute Disease; Adenosine Triphosphatases; Adenosine Triphosphate; Adult; Aldehydes; Animals; Disease Progression; Fatty Liver; Female; Humans; Ion Channels; Liver; Male; Membrane Potential, Mitochondrial; Middle Aged; Mitochondria, Liver; Mitochondrial Proteins; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Uncoupling Protein 2

The effect of the garlic-derived antioxidant S-allylcysteine (SAC) on renal injury and oxidative stress induced by ischemia and reperfusion (IR) was studied in this work. Rats were anesthetized and subjected to right nephrectomy; 15 min later ischemia was induced for a period of 40 min and then the rats were subjected to a reperfusion period of 6 h after which they were killed to obtain blood and the left kidney. SAC was given at a dose of 100 mg/kg 30 min before nephrectomy, 15 min before ischemia, immediately before reperfusion and 2 h after reperfusion. IR-induced renal injury was evident by the increase in blood urea nitrogen (BUN) and serum creatinine as well as by the renal structural damage which was assessed by histological analysis. IR-induced oxidative stress was evident by the increase in immunostaining with 4-hydroxy-2-nonenal (4-HNE). SAC treatment was able to ameliorate the increase in BUN and serum creatinine and to decrease the structural damage. This protective effect was associated with a decrease in the immunostaining for 4-HNE. It is concluded that the antioxidant properties of SAC are involved in its protective effect on renal ischemia and reperfusion injury.

Topics: Aldehydes; Animals; Antioxidants; Cysteine; Female; Garlic; Immunohistochemistry; Kidney; Kidney Diseases; Rats; Reperfusion Injury

Our previous studies have shown that ferulic acid (4-hydroxy-3-methoxycinnamic acid, FA) inhibits intercellular adhesion molecule-1 (ICAM-1) expression in the ischemic striatum after 2 h of reperfusion in a transient middle cerebral artery occlusion model in rats. The purpose of this study is to further investigate the neuroprotective effects of FA during reperfusion after cerebral ischemia. Rats were subjected to 90 min of ischemia; they were then sacrificed after 2, 10, 24 and 36 h of reperfusion. ICAM-1 and macrophage-1 antigen (Mac-1) mRNA were detected using semi-quantitative RT-PCR at 2 h of reperfusion. Mac-1, 4-hydroxy-2-nonenal (4-HNE), 8-hydroxy-2'-deoxyguanosine (8-OHdG), active caspase 3, neuronal nuclei (NeuN) and TUNEL positive cells were measured at 2, 10, 24 and 36 h of reperfusion. FA (100 mg/kg, i.v.) administered immediately after MCAo inhibited ICAM-1 and Mac-1 mRNA expression in the striatum at 2 h of reperfusion, and reduced the number of Mac-1, 4-HNE and 8-OHdG positive cells in the ischemic rim and core at 10, 24 and 36 h of reperfusion. FA decreased TUNEL positive cells in the penumbra at 10 h, and in the ischemic boundary and core at 24 and 36 h of reperfusion. FA curtailed active caspase 3 expression in the penumbra at 10 h and restored NeuN-labeled neurons in the penumbra and ischemic core at 36 h of reperfusion. FA decreased the level of ICAM-1 mRNA and the number of microglia/macrophages, and subsequently down-regulated inflammation-induced oxidative stress and oxidative stress-related apoptosis, suggesting that FA provides neuroprotection against oxidative stress-related apoptosis by inhibiting ICAM-1 mRNA expression after cerebral ischemia/reperfusion injury in rats.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Apoptosis; Brain Ischemia; Caspase 3; Coumaric Acids; Deoxyguanosine; Disease Models, Animal; DNA-Binding Proteins; Encephalitis; Free Radical Scavengers; Gene Expression; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Intercellular Adhesion Molecule-1; Macrophage-1 Antigen; Male; Nerve Tissue Proteins; Neuroprotective Agents; Nuclear Proteins; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA, Messenger

Damage of the placenta resulting from ischemia-reperfusion is important to the pathophysiology of preeclampsia. Here we investigated whether low concentrations of glyceryl trinitrate (GTN), a nitric oxide mimetic with anti-apoptotic properties, inhibit hypoxia/reoxygenation-induced apoptosis in the syncytiotrophoblast of chorionic villous explants from human placentas. Compared with villi analyzed immediately after delivery or maintained under normoxic conditions, villi exposed to a 6-hour cycle of hypoxia/reoxygenation exhibited greater numbers of syncytiotrophoblasts with terminal dUTP nick-end labeling (TUNEL)-positive nuclei in the syncytiotrophoblast. This increased number of TUNEL-positive nuclei was paralleled by higher levels of 4-hydroxynonenal (marker of lipid peroxidation), nitrotyrosine residues, and active caspase-3 and polyADP-ribose polymerase expression. Morphological analysis of explants exposed to hypoxia/reoxygenation revealed apoptotic and aponecrotic features similar to those of chorionic villi from preeclamptic pregnancies. Treatment with GTN during the hy-poxia/reoxygenation cycle blocked the increases in the number of TUNEL-positive nuclei and in the levels of 4-hydroxynonenal, nitrotyrosine, and active caspase-3. Incubation with GTN also attenuated the hypoxia/reoxygenation-induced polyADP-ribose polymerase expression and the apoptotic and aponecrotic morphological alterations. These results suggest that small concentrations of nitric oxide protect chorionic villi from hypoxia/reoxygenation-induced damage and provide a rationale for the use of low doses of nitric oxide mimetics in the treatment and/or prevention of preeclampsia.

Topics: Aldehydes; Apoptosis; Blotting, Western; Caspase 3; Collagen Type XI; Female; Humans; Hypoxia; Immunohistochemistry; In Situ Nick-End Labeling; Microscopy, Electron, Transmission; Nitroglycerin; Organ Culture Techniques; Pre-Eclampsia; Pregnancy; Reperfusion Injury; Tocolytic Agents; Trophoblasts; Tyrosine

The pathogenesis of ischemia-reperfusion involves generation of reactive oxygen and resulting lipid peroxidation. However, investigation that ischemia-reperfusion following tourniquet release enhances lipid peroxidation is insufficient.. Tourniquet was applied to a unilateral hind limb of mice for 3h followed by 5-, 15-, 30- and 60-min release. To examine superoxide production immunohistochemically in ischemia-reperfusion muscles, a primary antibody directed to 4-hydroxy-nonenal (HNE) was used. Furthermore, we analyzed 7alpha- and 7beta-hydroperoxycholest-5-en-3beta-ol, 7alpha- and 7beta-hydroxycholesterol, and 7-ketocholesterol by HPLC in the gastrocnemius muscles, kidneys, liver, heart and lungs of mice after 1-h reperfusion.. Increased HNE immunoreactivitiy was observed in the tourniquet-applied side of gastrocnemius muscles of hind limb particularly after 5-min reperfusion. All the oxysterols were significantly higher in the gastrocnemius muscles of the tourniquet-applied side than of the contralateral muscles. Oxysterols were elevated in the kidneys and the liver. Together with the presence of high blood urea nitrogen, these data indicate that the kidney is vulnerable to ischemia-reperfusion.. The enhanced oxidative stress due to ischemia-reperfusion appears to increase HNE in muscle and oxysterols by peroxidation not only in the gastrocnemius muscles but also in the kidneys and liver.

Topics: Aldehydes; Animals; Cholesterol; Heart; Hindlimb; Ischemia; Kidney; Lipid Peroxidation; Liver; Lung; Male; Mice; Mice, Inbred C57BL; Muscles; Reperfusion Injury; Superoxides; Time Factors; Tourniquets

Increased production of reactive oxygen species (ROS) following cerebral ischemia-reperfusion (I/R) is an important underlying cause for neuronal injury leading to delayed neuronal death (DND). In this study, apocynin, a specific inhibitor for NADPH oxidase, was used to test whether suppression of ROS by the NADPH oxidase inhibitor can protect against ischemia-induced ROS generation and decrease DND. Global cerebral ischemia was induced in gerbils by a 5-min occlusion of bilateral common carotid arteries (CCA). Using measurement of 4-hydroxy-2-nonenal (HNE) as a marker for lipid peroxidation, apocynin (5 mg/kg body weight) injected i.p. 30 min prior to ischemia significantly attenuated the early increase in HNE in hippocampus measured at 3 h after I/R. Apocynin also protected against I/R-induced neuronal degeneration and DND, oxidative DNA damage, and glial cell activation. Taken together, the neuroprotective effects of apocynin against ROS production during early phase of I/R and subsequent I/R-induced neuronal damage provide strong evidence that inhibition of NADPH oxidase could be a promising therapeutic mechanism to protect against stroke damage in the brain.

Topics: Acetophenones; Aldehydes; Animals; Antioxidants; Biomarkers; Brain Ischemia; Cell Death; Cerebral Infarction; Disease Models, Animal; DNA Damage; Enzyme Inhibitors; Gerbillinae; Gliosis; Hippocampus; Male; NADPH Oxidases; Nerve Degeneration; Neurons; Neuroprotective Agents; Oxidative Stress; Reactive Oxygen Species; Reperfusion Injury; Time Factors; Treatment Outcome

Prolonged hepatic warm ischemia has been incriminated in oxidative stress after reperfusion. However, the magnitude of oxidative stress during ischemia has been controversial. The aims of the present study were to elucidate whether lipid peroxidation progressed during ischemia and to clarify whether oxidative stress during ischemia aggravated the oxidative damage after reperfusion. Rats were subjected to 30 to 120 min of 70% warm ischemia alone or followed by reperfusion for 60 min. Lipid peroxidation (LPO) was evaluated by amounts of phosphatidylcholine hydroperoxide (PC-OOH) and phosphatidylethanolamine hydroperoxide (PE-OOH) as primary LPO products. Total amounts of malondialdehyde and 4-hydroxy-2-nonenal (MDA + 4-HNE), degraded from hydroperoxides, were also determined. PC-OOH and PE-OOH significantly increased at 60 and 120 min ischemia with concomitant increase of oxidized glutathione. These hydroperoxides did not increase at 60 min reperfusion after 60 min ischemia, whereas they did increase at 60 min reperfusion after 120 min ischemia with deactivation of phospholipid hydroperoxide glutathione peroxidase and superoxide dismutase. The amount of MDA + 4-HNE exhibited similar changes, but the velocity of production dropped with ischemic time longer than 60 min. In conclusion, oxidative stress progressed during ischemia and triggered the oxidative injury after reperfusion. Secondary LPO products are less sensitive, especially during ischemia, which may cause possible underestimation and discrepancy.

Topics: Aldehydes; Animals; Glutathione Peroxidase; Ischemia; Lipid Peroxidation; Liver; Liver Function Tests; Male; Malondialdehyde; Oxidative Stress; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipid Hydroperoxide Glutathione Peroxidase; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxide Dismutase; Survival Rate

In hepatic ischaemia/reperfusion injury, activated liver macrophages (Kupffer cells) are dominantly regulated by a transcription factor, nuclear factor kappaB (NFkappaB), with respect to expression of inflammatory cytokines, acute phase response proteins, and cell adhesion molecules.. We assessed whether inactivation of NFkappaB in the liver could attenuate total hepatic warm ischaemia/reperfusion injury.. We studied rats with hepatic overexpression of inhibitor kappaBalpha super-repressor (IkappaBalpha SR) caused by a transgene introduced using an adenoviral vector. Hepatic ischaemia/reperfusion injury was induced under warm conditions by total occlusion of hepatoduodenal ligament structures for 20 minutes, followed by reperfusion. Controls included uninfected and control virus (AdLacZ) infected rats.. IkappaBalpha SR was overexpressed in Kupffer cells as well as in hepatocytes, blocking nuclear translocation of NFkappaB (p65) into the nucleus after reperfusion. Gene transfection with IkappaBalpha SR, but not with LacZ, markedly attenuated ischaemia/reperfusion injury, suppressing inducible nitric oxide synthase and nitrotyrosine expression in the liver. Moreover, no remarkable hepatocyte apoptosis was detected under IkappaBalpha SR overexpression.. Adenoviral transfer of the IkappaBalpha SR gene in the liver ameliorates short term warm ischaemia/reperfusion injury, possibly through attenuation of hepatic macrophage activation.

Topics: Adenoviridae; Aldehydes; Animals; Blotting, Western; Gene Transfer Techniques; Hepatocytes; I-kappa B Proteins; Kupffer Cells; Liver; Male; NF-kappa B; NF-KappaB Inhibitor alpha; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Tumor Necrosis Factor-alpha; Tyrosine

Hepatic warm ischemia-reperfusion injury (IRI) during hepatectomy and liver transplantation is a major cause of liver dysfunction in which the pathologic role of free radicals is a major concern. To assess the effect of MCI-186 (edaravone) on hepatic IRI, male Wistar rats were subjected to partial hepatic ischemia for 60 min after pretreatment with vehicle (group C) or MCI-186 (group M), or after both MCI-186 pretreatment and additional administration of MCI-186 12 h after reperfusion (group MX). Groups M and MX showed significantly lower levels of serum alanine aminotransferase and hepatic lipid peroxidation than group C, and also significantly lower expression levels of mRNA for cytokines, chemokines and intercellular adhesion molecule-1. There were fewer tissue monocytes and neutrophils in groups M and MX than in group C. These effects were more marked in group MX than in group M. Our findings suggest that treatment with MCI-186 attenuates hepatic IRI in this rat in vivo model.

Topics: Alanine Transaminase; Aldehydes; Animals; Antipyrine; Chemokines; Cytokines; Edaravone; Free Radical Scavengers; Immunohistochemistry; Liver; Macrophages; Male; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger; Time Factors

Oxidative stress contributes to ischemia/reperfusion neuronal damage in a consecutive 2-phase pattern: an immediate direct cytotoxic effect and subsequent redox-mediated inflammatory insult. The present study was designed to assess the neuroprotective mechanisms of edaravone, a novel free radical scavenger, through antioxidative and anti-inflammatory pathways, from the early period to up to 7 days after ischemia/reperfusion in mice.. Mice were subjected to 60-minute ischemia followed by reperfusion. They were divided into the edaravone group (n=72; with different schedules for first administration) and the vehicle (control) group (n=36). Infarct volume and neurological deficit scores were evaluated at several time points after ischemia. Immunohistochemical analysis for 4-hydroxy-2-nonenal (HNE), 8-hydroxy-deoxyguanosine (8-OHdG), ionized calcium-binding adapter molecule 1 (Iba-1), inducible NO synthase (iNOS), and nitrotyrosine were performed at 24 hours, 72 hours, or 7 days after reperfusion.. Edaravone, even when administrated 6 hours after onset of ischemia/reperfusion, significantly reduced the infarct volume (68.10+/-6.24%; P<0.05) and improved the neurological deficit scores (P<0.05) at 24 hours after reperfusion. Edaravone markedly suppressed the accumulation of HNE-modified protein and 8-OHdG at the penumbra area during the early period after reperfusion (P<0.05) and reduced microglial activation, iNOS expression, and nitrotyrosine formation at the late period.. Our results indicated that edaravone exerts an early neuroprotective effect through the early free radicals scavenging pathway and a late anti-inflammatory effect and suggested that edaravone is important for expansion of the therapeutic time window in stroke patients.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Anti-Inflammatory Agents; Antioxidants; Antipyrine; Brain; Brain Ischemia; Deoxyguanosine; DNA Damage; Edaravone; Electrophoresis, Polyacrylamide Gel; Free Radical Scavengers; Immunoblotting; Immunohistochemistry; Inflammation; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Oxidative Stress; Reperfusion Injury; Time Factors; Tyrosine

1. The effects of short-term oral administration of red wine polyphenolic compounds (RWPC, 20 mg x kg(-1) day(-1) for 7 days) on haemodynamics, ex vivo cardiac responsiveness and ischaemia-reperfusion injury were investigated in rats. The involvement of nitric oxide (NO) was evaluated using the NO synthase inhibitor, N(G)-nitro-l-arginine methyl ester (l-NAME, 2 mg x kg(-1) day(-1) for 7 days), at a dose which did not affect blood pressure. 2. Ex vivo reactivity of hearts from RWPC-treated rats showed lower basal developed pressure, greater heart rate and decreased inotropic responses to either beta-adrenoceptor or muscarinic receptor stimulation with isoprenaline or carbachol, respectively.3. RWPC treatment did not modify cardiac expression of endothelial NO synthase or Cu/Zn superoxide dismutase. However, it increased nitrite in the coronary effluent. 4. In ischaemia-reperfusion, RWPC treatment reduced infarct size and oxidative stress, as shown by the myocardial content of the end products of lipid peroxidation, malondialdehyde and 4-hydroxynonenal, without affecting post-ischaemic contractile dysfunction. All the observed effects of RWPC were prevented by l-NAME treatment. 5. Altogether, these data show that short-term treatment with RWPC decreases blood pressure and cardiac responsiveness, and protects against post-ischaemic infarction via decreased oxidative stress. All the above effects of RWPC are sensitive to NO synthase inhibition that implies an involvement of NO-dependent pathway. This study suggests a basis for the beneficial effects of plant-derived polyphenols against cardiovascular disease.

Topics: Administration, Oral; Aldehydes; Animals; Blood Pressure; Blotting, Western; Carbachol; Coronary Circulation; Drug Administration Schedule; Drug Therapy, Combination; Flavonoids; France; Heart Rate; Heart Ventricles; Hypotension; Isoproterenol; Male; Malondialdehyde; Myocardial Infarction; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitrites; Phenols; Polyphenols; Rats; Rats, Wistar; Reperfusion Injury; Time Factors; Ventricular Function; Ventricular Pressure; Wine

Free radicals induced by cerebral ischemia-reperfusion injury can trigger lipid peroxidation, leading to the production of malondialdehyde (MDA) and 4-hydroxy-2(E)-nonenal (4-HNE). Post-ischemia electroacupuncture (EA) therapy was able to reduce extent of lipid peroxidation. However, the effect of pre-ischemic EA therapy has not been reported. In this study, we aim to investigate the effectiveness of pre-ischemic EA therapy on lipid peroxidation in the rat ischemic injury model. Four groups of Sprague-Dawley rats were designed: Placebo group (without EA therapy), NA group (EA therapy on non-acupoint), GB20 group (EA therapy on Fengchi), and ST36 group (EA therapy on Zusanli). Half of each group (n = 6) received 30-minute EA therapy for 3 times and the other half group for 18 times before the occlusion of right middle cerebral artery. Right brains were taken for determination of concentration of MDA and the total of MDA plus 4-HNE. We found that multiple pre-ischemia EA therapy at either GB20 or ST36 can effectively reduce the amount of MDA produced after MCA occlusion. However, this reduction was not observed in the total amount of MDA and 4-HNE. In conclusion, pre-ischemia EA can partly regulate the lipid peroxidation in cerebral ischemia, where both GB20 and ST36 have a similar beneficial effectiveness.

Topics: Aldehydes; Animals; Brain; Brain Chemistry; Electroacupuncture; Hypoxia-Ischemia, Brain; Lipid Peroxidation; Male; Malondialdehyde; Medicine, Chinese Traditional; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Free radicals are involved in the protective mechanism of preconditioning (PC), whereas antioxidant compounds abolish this benefit. Melatonin is a hormone with antioxidant properties. The aim of our study was to evaluate the effect of melatonin on infarct size in ischemic preconditioning in vivo. We randomly divided 33 male rabbits into four groups and subjected them to 30 min of myocardial ischemia and 3 h of reperfusion with the following prior interventions: (i) no intervention, (ii) iv melatonin at a total dose of 50 mg/kg, (iii) PC with two cycles of 5 min ischemia and 10 min reperfusion, and (iv) combined melatonin and PC. In a second series of experiments, another antioxidant agent N-acetylcysteine (NAC) was used in a control and in a PC group. Myocardial infarct size was determined and blood samples were drawn at different time points for the determination of lipid peroxidation products, total superoxide dismutase (SOD) activity, and (1)H-NMR spectra to evaluate the changes in the metabolic profile. Melatonin showed no effect on myocardial infarct size in the group of sustained ischemia (42.9 +/- 3.6% vs 47.4 +/- 4.9%) and it did not attenuate the reduction of myocardial infarct size in the PC group (13.6 +/- 2.4% vs 14.0 +/- 1.7%). A similar effect was found in NAC-treated groups (44.8 +/- 3.4% vs 14.3 +/- 1.3%). Lipid peroxidation product levels were significantly elevated in the control and PC groups, whereas melatonin decreased them in both groups. The SOD activity was enhanced in the PC group compared to controls; melatonin kept SOD activity unchanged during ischemia/reperfusion and enhanced its activity when it was combined with PC. Melatonin did not change the metabolic profile of the control and PC groups. Melatonin does not prevent the beneficial effect of ischemic PC on infarct size despite its antioxidant properties.

Topics: Acetylcysteine; Aldehydes; Animals; Antioxidants; Free Radicals; Ischemic Preconditioning; Lipid Peroxidation; Magnetic Resonance Spectroscopy; Male; Malondialdehyde; Melatonin; Models, Statistical; Oxidative Stress; Rabbits; Reperfusion Injury; Superoxide Dismutase; Time Factors

It has been shown that the renin-angiotensin system (RAS) plays key roles in the development of fibrosis in numerous organs, including the liver. Other studies have suggested that the RAS also may play roles in diseases of chronic inflammation. However, whether the RAS also can mediate acute inflammation in liver is unclear. The purpose of this study therefore was to determine the effect of the RAS inhibitors captopril and losartan on acute liver damage and inflammation caused by hepatic ischemia and subsequent reperfusion. Accordingly, male rats were subjected to 1 hour of hepatic ischemia (70%) followed by reperfusion; animals were killed 3, 8, or 24 hours after reperfusion. The effect of captopril or losartan (100 or 5 mg/kg intragastrically, respectively) was compared with that of vehicle (saline). The expression of angiotensinogen in liver increased fivefold 3 hours after reperfusion. Indices of liver damage and inflammation (e.g., alanine aminotransferase levels, pathological features, tumor necrosis factor-alpha levels, and intercellular adhesion molecule-1 expression) all were significantly elevated in vehicle-treated animals after hepatic ischemia and subsequent reperfusion. Ischemia and reperfusion also caused an increase in the accumulation of protein adducts of 4-hydroxynonenal, an index of oxidative stress. Captopril or losartan treatment showed profound protective effects under these conditions, significantly blunting the increase in all these parameters caused by ischemia and reperfusion. In conclusion, RAS inhibitors prevent acute liver injury in a model of inflammation caused by ischemia and reperfusion. These data further suggest that the RAS may play a key role in mediating such responses in the liver and suggest a novel role for this system.

Topics: Alanine Transaminase; Aldehydes; Animals; Captopril; Gene Expression Regulation; Intercellular Adhesion Molecule-1; Liver; Male; Neutrophils; Rats; Rats, Sprague-Dawley; Renin-Angiotensin System; Reperfusion Injury; Tumor Necrosis Factor-alpha

Increasing evidence indicates that protein-aldehyde adducts involving mostly 4-hydroxynonenal could be causally involved in both pathophysiological and adaptive events following an oxidative stress insult such as ischemia/reperfusion. The goal of this study was to assess if isotope dilution chromatography-mass spectrometry can be used to quantitate changes in the cardiac levels of 4-hydroxynonenal and 1,4-dihydroxynonene, one of its major metabolites, bound to thiol proteins during ischemia/reperfusion. For this purpose, we modified a previously published method to include treatment with Raney Nickel, which specifically cleaves thioether linkages. Our study model was the isolated Langendorff-perfused rat heart subjected to various ischemia/reperfusion protocols. Hearts perfused under normoxia contained small amounts of protein-bound 4-hydroxynonenal and 1,4-dihydroxynonene (1.38 +/- 0.29 and 2.69 +/- 0.17 nmol/g wet weight, respectively). The accumulation of these adducts after global ischemia depended on the severity of the ischemic insult up to a plateau and was not exacerbated by reperfusion. In conclusion, our method allows the quantification of time-dependent changes in 4-hydroxynonenal and 1,4-dihydroxynonene bound to proteins via thioether linkage in ischemic/reperfused heart tissues. The presence of protein-bound 1,4-dihydroxynonene in heart tissues suggests that this organ can detoxify protein-bound 4-hydroxynonenal.

Topics: Aldehydes; Animals; Free Radicals; Gas Chromatography-Mass Spectrometry; Heart; Male; Myocardium; Oxygen; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfhydryl Compounds; Sulfides; Temperature; Time Factors

Heat shock preconditioning (HSPC) is a promising strategy for providing ischemic tolerance. The objective of this study is to investigate the effectiveness of HSPC in preventing oxidative damage of cellular proteins and DNA during ischemia-reperfusion of the liver. Male Wistar rats were divided into a heat shock group (group HS) and control (group C). Forty-eight hours prior to ischemia, rats in group HS received HSPC at 42 degrees C for 15 min. All rats received hepatic warm ischemia for 30min and subsequent reperfusion. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (HNE) modified proteins in liver tissue, survival rate of the animals, and changes in biochemical and histological parameters were compared between groups. Heat shock protein 72 was produced only in group HS. The 7-day survival of rats was significantly better in group HS (10/10) than in group C (5/10) (p < 0.01). The serum release of alanine aminotransferase (n = 10, p < 0.01) and the concentration of adenosine triphosphate in liver tissue (n = 10, p < 0.01) 40min after reperfusion was significantly better in group HS than in group C. The formation of 8-OHdG in liver tissue measured by high-performance liquid chromatography was suppressed in group HS (p < 0.01). The production of HNE-modified proteins as determined by Western-blot analysis was also decreased in group HS. These results were also confirmed by immunohistochemical analysis. As determined by levels of 8-OHdG and HNE-modified proteins produced during ischemia-reperfusion of the liver, HSPC reduced the oxidative injury of cellular proteins and DNA in the liver tissue.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Body Temperature; Deoxyguanosine; DNA Damage; Heat-Shock Proteins; Heat-Shock Response; HSP72 Heat-Shock Proteins; Hyperthermia, Induced; Liver; Male; Protein Processing, Post-Translational; Rats; Rats, Wistar; Reperfusion Injury; Survival Rate

Free radical-induced oxidative damages of macromolecules and cell death are important factors in the pathogenesis of ischemia/reperfusion brain injury. In the present study, an investigation as to whether green tea extract reduces ischemia/reperfusion-induced brain injury in Mongolian gerbils was conducted. The effect of green tea on the ischemia/reperfusion-induced production of hydrogen peroxide, lipid peroxidation and oxidative DNA damage (formation of 8-hydroxydeoxyguanosine), and cell death in addition to locomotor activity was studied. Two doses (0.5 or 2%) of green tea extract were added into the drinking water and to be accessed by animals ad libitum for 3 weeks prior to the induction of ischemia. A global ischemia was induced by the bilateral occlusion of the common carotid arteries for 5 min. Reperfusion was achieved by releasing the occlusion and restoring blood circulation for 48 h. The infarction volumes were 112+/-31 mm(3) and 76+/-11 mm(3) in the 0.5 and 2% green tea pretreated animals compared to 189+/-12 mm(3) in the ischemia/reperfusion animals. Green tea extract also reduced the levels of ischemia/reperfusion-induced hydrogen peroxide (from 1470+/-170 to 1034+/-46 and 555+/-30 nmole/mg protein), lipid peroxidation products (from 1410+/-210 to 930+/-40 and 330+/-20 nmole/mg protein) and 8-oxodG (from 3.9+/-0.1 to 2.8+/-0.3 and1.9+/-0.3 ng/microg DNA, x10(-2)) by pretreatment of 0.5 or 2% green tea for 3 weeks, respectively. Moreover, green tea also reduced the number of ischemia/reperfusion-induced apoptotic cells (from 59+/-12 to 37+/-8, 15+/-11 apoptotic cells/high power field in the striatum region) and locomotor activity (from 15140+/-2940 to 3900+/-600 and 4100+/-1200). This study therefore suggests that green tea may be a useful agent for the prevention of cerebral ischemia damage.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Apoptosis; Beverages; Brain; Brain Infarction; Cerebrovascular Circulation; Cysteine Proteinase Inhibitors; Deoxyguanosine; DNA; Female; Gerbillinae; Hydrogen Peroxide; Ischemic Attack, Transient; Lipid Peroxidation; Malondialdehyde; Motor Activity; Neurons; Oxidative Stress; Plant Extracts; Reperfusion Injury

Previous evidence suggests that both oxygen radicals and nitric oxide (NO) are important mediators of injury during renal ischemia-reperfusion (I-R) injury. However, the generation of reactive nitrogen species (RNS) has not been evaluated in this model at early time points. The purpose of these studies was to examine the development of oxidant stress and the formation of RNS during I-R injury. Male Sprague-Dawley rats were anesthetized and subjected to 40 min of bilateral renal ischemia followed by 0, 3, or 6 h of reperfusion. Control animals received a sham operation. Plasma urea nitrogen and creatinine levels were monitored as markers of renal injury. Glutathione (GSH) oxidation and 4-hydroxynonenal (4-HNE)-protein adducts were used as markers of oxidant stress. 3-Nitrotyrosine (3-NT) was used as a biomarker of RNS formation. Significant increases in plasma creatinine concentrations and urea nitrogen levels were found following both 3 and 6 h of reperfusion. Increases in GSH oxidation, 4-HNE-protein adduct levels, and 3-NT levels were observed following 40 min of ischemia with no reperfusion. Since these results suggested RNS generation during the 40 min of ischemia, a time course of RNS generation following 0, 5, 10, 20, and 40 min of ischemia was evaluated. Significant increases in 3-NT generation was detected as early as 10 min of ischemia and rose to values nearly 10-fold higher than Control at 40 min of ischemia. No additional increase was observed following reperfusion. The data clearly demonstrate that oxidative stress and RNS generation occur in the kidney during ischemia.

Topics: Aldehydes; Animals; Blood Urea Nitrogen; Creatinine; Free Radicals; Glutathione; Kidney; Male; Nitrates; Oxidation-Reduction; Oxidative Stress; Proteins; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors; Tyrosine

Oxidative stress is a prominent feature of the placenta in many complications of pregnancy, such as preeclampsia. The cause is primarily unknown, although ischemia-reperfusion injury is one possible mechanism. Our aim was to test this hypothesis by examining the oxidative status of human placental tissues during periods of hypoxia and reoxygenation in vitro. Rapid generation of reactive oxygen species was detected using the fluorogenic probe, 2',7'-dichlorofluorescein diacetate, when hypoxic tissues were reoxygenated. The principal sites were the villous endothelium, and to a lesser extent the syncytiotrophoblast and stromal cells. Increased concentrations of heat shock protein 72, nitrotyrosine residues, and 4-hydroxy-2-nonenal were also observed in the villous endothelial and underlying smooth muscle cells, and in the syncytiotrophoblast. Furthermore, preloading placental tissues with the reactive oxygen species scavengers desferrioxamine and alpha-phenyl-N-tert-butylnitrone reduced levels of oxidative stress after reoxygenation. These changes are consistent with an ischemia-reperfusion injury, and mirror those seen in preeclampsia. Consequently, in vitro hypoxia/reoxygenation may represent a suitable model system for investigating the generation of placental oxidative stress in preeclampsia and other complications of pregnancy.

Topics: Aldehydes; Cyclic N-Oxides; Deferoxamine; Female; Fluorescent Antibody Technique; Heat-Shock Proteins; HSP72 Heat-Shock Proteins; Humans; Hypoxia; Immunohistochemistry; Ischemia; Nitrogen Oxides; Oxidative Stress; Oxygen; Placenta; Pregnancy; Pregnancy Complications; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase; Tissue Distribution; Tyrosine

Mitochondrial dysfunction is a characteristic of ischemia/reperfusion (I/R) injury in the heart. While oxidative stress has been implicated in mitochondrial damage in I/R injury, the underlying mechanisms are unclear. 4-Hydroxynonenal (HNE) is a toxic aldehyde generated by lipid peroxidation. The purpose of the present study was to assess the role of HNE in I/R-induced damage of a crucial component of the mitochondrial electron transport chain, cytochrome c oxidase (COX). I/R was induced in male WKY rats by 15 mins of ischemia followed by reperfusion for up to 3 h. COX activity was measured spectrophotometrically at 550 nm. HNE adducts with COX subunits were detected by Western Blot using an HNE-histidine antibody. HNE and reduced glutathione (GSH) contents were measured in mitochondria by HPLC. Following 3 h of reperfusion, COX activity was reduced to 59% of control, accompanied by increases in HNE adducts with COX (P<0.05). Mitochondrial HNE content in reperfused hearts was increased to 165% of control, whereas GSH was decreased to 62% of control (P<0.05). After purified COX was incubated with HNE in vitro, COX activity was decreased progressively with increasing concentrations of HNE, accompanied by concentration-dependent formation of HNE adducts with COX. GSH prevented HNE adduct formation as well as COX inhibition by HNE. These results suggest that HNE, via adduct formation with COX subunits, plays an important role in COX dysfunction caused by reperfusion. The findings also indicate that decreases in mitochondrial GSH stores in reperfused myocardium could potentiate HNE-mediated COX damage.

Topics: Aldehydes; Animals; Blotting, Western; Chromatography, High Pressure Liquid; Cysteine Proteinase Inhibitors; Dose-Response Relationship, Drug; Electron Transport Complex IV; Glutathione; Growth Inhibitors; Male; Myocardial Ischemia; Myocardial Reperfusion; Myocardium; Oxidative Stress; Rats; Rats, Inbred WKY; Reperfusion Injury; Time Factors

To investigate whether lipid peroxides play a role in retinal cell death due to ischemia-reperfusion injury, whether recombinant human thioredoxin (rhTRX) treatment reduces production of lipid peroxides of the retina, and whether such treatment reduces the number of cells expressing c-Jun and cyclin D1.. Retinal ischemia was induced in rats by increasing the intraocular pressure to 110 mm Hg for 60 minutes. After reperfusion, immunohistochemical staining for lipid peroxide, peroxynitrite, c-Jun, and cyclin D1 and propidium iodide (PI) staining were performed on retinal sections from animals treated intravenously with and without rhTRX, a free radical scavenger. Quantitative analyses of PI-, c-Jun-, and cyclin D1-positive cells were performed after the ischemic insult. Concentration of lipid peroxides in the retina was determined by the thiobarbituric acid assay.. Specific immunostaining for lipid peroxides was seen in the ganglion cell layer at 6 hours after reperfusion, in the inner nuclear layer at 12 hours, and in the outer nuclear layer at 48 hours. Time course studies for PI-positive cells in the three nuclear layers coincided with those of specific immunostaining for lipid peroxides. The specific immunostaining was weakened by pre- and posttreatment with 0.5 mg of rhTRX. The number of PI-, c-Jun-, and cyclin D1-positive cells and the concentration of lipid peroxides were significantly decreased by treatment with rhTRX compared with those of vehicle-treated control rats (P: < 0. 01).. Lipid peroxides formed by free radicals may play a role in neuronal cell death in retinal ischemia-reperfusion injury.

Topics: Aldehydes; Animals; Cell Death; Cyclin D1; Fluorescent Antibody Technique, Indirect; Free Radical Scavengers; Lipid Peroxidation; Lipid Peroxides; Male; Nitrates; Propidium; Proto-Oncogene Proteins c-jun; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Reperfusion Injury; Retina; Retinal Diseases; Thiobarbituric Acid Reactive Substances; Thioredoxins

It has been proposed that reactive oxygen species and lipid peroxidation have a role in the delayed neuronal death of pyramidal cells in the CA1 region. To explore the in situ localization and serial changes of 4-hydroxy-2-nonenal-modified proteins, which are major products of membrane peroxidation, we used immunohistochemistry of the gerbil hippocampus after transient forebrain ischemia with or without preconditioning ischemia. The normal gerbil hippocampus showed weak immunoreactivity for 4-hydroxy-2-nonenal-modified proteins in the cytoplasm of CA1 pyramidal cells. 4-hydroxy-2-nonenal immunoreactivity showed no marked changes after preconditioning ischemia. In the early period after ischemia and reperfusion, there was a transient increase of nuclear 4-hydroxy-2-nonenal immunoreactivity in CA1 pyramidal neurons. In contrast, cytoplasmic immunoreactivity transiently disappeared during same period and then increased markedly from 8h to seven days. One week after ischemia, 4-hydroxy-2-nonenal immunoreactivity was observed within reactive astrocytes in the CA1 region. Early nuclear accumulation of 4-hydroxy-2-nonenal in CA1 neurons may indicate a possible role in signal transduction between the nucleus and cytoplasm/mitochondria, while delayed accumulation of 4-hydroxy-2-nonenal-modified proteins in the cytoplasm may be related to mitochondrial damage. We conclude that 4-hydroxy-2-nonenal may be a key mediator of the oxidative stress-induced neuronal signaling pathway and may have an important role in modifying delayed neuronal death.

Topics: Aldehydes; Animals; Brain Ischemia; Cell Death; Gerbillinae; Lipid Peroxidation; Male; Pyramidal Cells; Reperfusion Injury; Signal Transduction

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

4-Hydroxy-2-nonenal (HNE)-modified proteins and 3-nitro-L-tyrosine were evaluated as a specific marker of reactive oxygen species (ROS)- and nitric oxide (NO)-mediated peroxynitrite-induced tissue injuries in ischemic and reperfused skin flap by Western blot analysis. Specimens were taken from island skin flaps of rats during the following three conditions: ischemia only, 5 hours of ischemia and reperfusion, and 10 hours of ischemia and reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine increased with ischemic time (3, 6, and 10 hours postischemia). In the reperfused skin flap after both 5 and 10 hours of ischemia, HNE-modified proteins and 3-nitro-L-tyrosine were increased 3 hours postreperfusion, and they reached a maximum 6 hours after reperfusion. HNE-modified proteins and 3-nitro-L-tyrosine 1 hour postreperfusion were higher with 10 hours ischemia-reperfusion than with 5 hours ischemia-reperfusion. These results indicate (1) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity in ischemic flaps is dependent on the ischemic period and (2) that ROS- and NO-induced peroxynitrite-mediated cytotoxicity occurs during an early stage of reperfusion if the ischemic period is long.

Topics: Aldehydes; Animals; Blotting, Western; Free Radicals; Ischemia; Male; Proteins; Rats; Rats, Wistar; Reperfusion Injury; Skin; Specific Pathogen-Free Organisms; Surgical Flaps; Tyrosine

Topics: Aldehydes; Antioxidants; Cholestasis; Humans; Liver Cirrhosis; Liver Transplantation; Malondialdehyde; Oxidation-Reduction; Postoperative Complications; Postoperative Period; Regression Analysis; Reperfusion Injury; Syndrome

Bcl-2 has a role in suppressing the production of reactive oxygen species and lipid peroxidation. To explore the in situ localization of 4-hydroxy-2-nonenal (HNE)-modified proteins and the Bcl-2 oncoprotein, we used double immunofluorescence labeling and confocal imaging in the rat brain after 3 h of middle cerebral artery (MCA) occlusion followed by reperfusion. Immunoreactivity for HNE or Bcl-2 was not detected at 1 h, but appeared in some intact neurons in the boundary between the infarcted and non-infarcted zones at 12 h. At 48 h, HNE-positive microglia were colocalized with Bcl-2 in the infarcted area and the boundary zone. Bcl-2 may play an important role in the antioxidant system promoting survival of the neurons and activated microglia following reperfusion injury.

Topics: Aldehydes; Animals; Brain Chemistry; Ischemic Attack, Transient; Lipid Peroxidation; Male; Microglia; Microscopy, Confocal; Microscopy, Fluorescence; Nerve Tissue Proteins; Neurons; Oxidative Stress; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury

To assess the role of superoxide (O2-) and nitric oxide (NO) in ischaemic-reperfusion-induced acute renal failure, we investigated whether an activation of the L-arginine-NO pathway contributes to ischaemia-reperfusion-induced kidney membrane peroxidation by measurement of 4-hydroxynonenal (HNE) content in anaesthetized rats submitted to acute renal ischaemia. Following ischaemia-reperfusion injury, renal blood flow (RBF) was significantly reduced, while renal vascular resistance was significantly increased. Infusion of neither L-arginine nor D-arginine led to a recovery of RBF. L-Arginine, but not D-arginine, caused a significant increase in HNE accumulation in the ischaemic kidney. L-Arginine infusion enhanced the degree of lipid peroxidation afforded by ischaemia-reperfusion injury in the kidney suggesting that products of the endogenous L-arginine-NO pathway may react with O2- to initiate lipid peroxidation.

Topics: Aldehydes; Animals; Arginine; Cricetinae; Ischemia; Kidney; Lipid Peroxidation; Male; Nitric Oxide; Rats; Rats, Wistar; Reactive Oxygen Species; Renal Circulation; Reperfusion Injury; Superoxides; Vascular Resistance

Hyperoxic cardiopulmonary resuscitation (CPR) is associated with an increase in neurologic dysfunction upon successful resuscitation with much of the damage attributable to an increase in reperfusion oxidant injury. We hypothesized that by contrast, hypoxic ventilation during resuscitation would improve neurologic outcome by reducing available substrate necessary for oxidant injury. Specifically, this study investigated the effects of 2 levels of hypoxic ventilation during resuscitation: F1O2 = 0.085, PaO2 = 26.6 +/- 3.4 mmHg, (HY8), and F1O2 = 0.12, PaO2 = 33.0 +/- 4.2 mmHg, (HY12), and normoxic resuscitation: F1O2 = 0.21, PaO2 = 60.6 +/- 17.0 mmHg, (N) on survival and neurological outcome following 9 min of normothermic cardiac arrest. Concentrations of malonaldehyde (MDA) and 4-hydroxynonenal (4-OH) in plasma and concentrations of glutathione (GSH) in erythrocyte lysates were measured to quantify possible radical damage. Physiological variables including arterial blood gases were followed for 24 h after resuscitation. Neurologic outcome was assessed using a standardized scoring system. Hypoxically (HY8) resuscitated dogs tended to have a greater neurologic deficit than normoxically resuscitated dogs and had reduced overall survival (16.9 +/- 8.9 h) compared to N dogs (24.0 +/- 0.0 h). Overall survival time correlated negatively (-0.693) and significantly (P = 0.0018) with plasma glucose concentration. Arterial plasma glucose concentrations were higher in the HY8 group compared to the N group immediately (HY8, 312 +/- 86 mg/dL; N, 196 +/- 82 mg/dL; P = 0.17) and 30 min (HY8, 331 +/- 109 mg/dL; N, 187 +/- 74 mg/dL; P = 0.077) following resuscitation. No statistically discernible differences in markers of oxidant injury were apparent among the 3 groups, but pooled data increased significantly with time for MDA and 4-OH. Pooled data for GSH showed a significant drop at 1 h following resuscitation and returned to normal by 6 h. Data from these markers suggested attendant oxidant injury in all groups. Thus, hypoxic ventilation at 2 depths of hypoxia during resuscitation failed to improve neurologic outcome beyond that achieved by ventilation with air, suggesting that normoxia rather than hyperoxia or hypoxia is the ideal target for arterial oxygenation during resuscitation.

Topics: Aldehydes; Animals; Blood Glucose; Brain Ischemia; Cardiopulmonary Resuscitation; Central Nervous System Diseases; Dogs; Erythrocytes; Glutathione; Heart Arrest; Male; Malondialdehyde; Neurologic Examination; Oxygen; Oxygen Inhalation Therapy; Reperfusion Injury; Respiration, Artificial

Ischemia (one hour) and following reperfusion (up to one hour) of the small intestine induce biochemical changes which are indices for the formation and action of oxygen free radicals and which occur predominantly during the reperfusion period. But the villi and the epithelial cells show different patterns of damage, occurring both at the end of the ischemic period and during the reperfusion period. Although the quantitative morphological changes are increased during the reperfusion in comparison with the ischemic phase the quality of the pattern of structural damage is the same in both periods of the experiment. This pattern of the damage includes: 1. the neighbourhood of groups of villi with total ischemic-lytic dissolution of the villi, of villi with damage of the epithelial cells at the tip and at the lateral area and of normal villi; 2. the different degree of structural damage of neighbouring epithelial cells within one villus whose cells are either of regular structural or damaged at subcellular organelles including the plasma membrane or of those being necrotically destroyed and on the way of release into the luminal space; 3. a differentiation of the structural changes of the microvilli and other organelles within single and neighbouring epithelial cells. The biochemical findings on purine nucleotide metabolism and on the formation of oxygen free radicals as "mean values" of a homogenate from a large group of cells cannot reflect the morphological-ultrastructural changes of single villi or even single epithelial cells. The possible reasons for the mosaicism of the morphological changes during ischemia and reperfusion are discussed.

Topics: Adenosine Triphosphate; Aldehydes; Animals; Glutathione; Guanosine Triphosphate; Intestine, Small; Male; Microscopy, Electron; Rats; Rats, Wistar; Reperfusion Injury