4-hydroxy-2-nonenal and Necrosis

While most of the investigations into the causative events in the development of alcoholic liver disease (ALD) have been focused on multiple factors, increasing interest has centered around the possible role of immune mechanisms in the pathogenesis and perpetuation of ALD. This is because many of the clinical features of ALD suggest that immune effector mechanisms may be contributing to liver tissue damage, as evidenced by the detection of circulating autoantibodies, and the presence of CD4+ and CD8+ lymphoid cells in the livers of patients with ALD. One mechanism that has been associated with the development of autoimmune responses is the modification (haptenation or adduction) of liver proteins with aldehydes or other products of oxidative stress. This is because it has been shown that these adducted proteins can induce specific immune responses, to the adduct, the adduct plus protein (conformational antigens), as well as the unmodified parts of the protein. More importantly, it is possible to demonstrate that adducted self-proteins can induce reactivity to the normal self-protein and thereby induce autoimmune responses. Therefore, it is the purpose of this manuscript to outline the mechanism(s) by which these modified self proteins can induce autoimmune reactivity, and thus play a role in the development and/or progression of ALD.

Topics: Acetaldehyde; Aldehydes; Animals; Apoptosis; Autoimmune Diseases; Autoimmunity; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Death; Disease Progression; Haptens; Hepatitis; Humans; Immune System; Lipoproteins, LDL; Liver; Liver Diseases, Alcoholic; Malondialdehyde; Necrosis; Oxidative Stress; Receptors, Scavenger; Self Tolerance

The major difficulty in establishing a clinical effective bioartificial liver assist device for treatment of fulminate hepatic failure is limitation of our knowledge and technologies about fresh cell behaviors in culture and a lack of knowledge about the etiology and pathogenesis of hepatic coma. Increasing data from clinical and laboratory investigation have accrued indicating that toxins from necrotic liver tissue, mainly as oxygen reactive substances, have a role in the pathogenesis of hepatic encephalopathy and even multiple system organs failure. This paper presents the data available and suggests a new pathway for artificial and bioartificial liver assist system.

Topics: Aldehydes; Animals; Bioreactors; Brain; Cells, Cultured; Equipment Design; Free Radicals; Glutathione; Hepatic Encephalopathy; Humans; Inactivation, Metabolic; Lipid Peroxidation; Liver; Liver Failure; Liver Transplantation; Liver, Artificial; Multiple Organ Failure; Necrosis; Oxidative Stress; Rabbits; Toxins, Biological

4-Hydroxynonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological effects. Normal and malignant cells of the same origin express different sensitivity to HNE. We used human osteosarcoma cells (HOS) in different stages of differentiation in vitro, showing differences in mitosis, DNA synthesis, and alkaline phosphatase (ALP) staining. Differentiated HOS cells showed decreased proliferation (

Topics: Aldehydes; Alkaline Phosphatase; Apoptosis; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell Survival; Glutathione; Glutathione Transferase; Humans; Lipid Peroxidation; Necrosis; Osteosarcoma; Proteasome Endopeptidase Complex

Oxidative stress is a major factor explaining sperm dysfunction of spermatozoa surviving freezing and thawing and is also considered a major inducer of a special form of apoptosis, visible after thawing, in cryopreserved spermatozoa. To obtain further insights into the link between oxidative stress and the induction of apoptotic changes, stallion spermatozoa were induced to oxidative stress through redox cycling after exposure to 2-methyl-1,4-naphthoquinone (menadione), or hydroxyl radical formation after FeSO

Topics: Aldehydes; Animals; Apoptosis; Caspase 3; Dinoprost; Ferrous Compounds; Horses; Hydroxyl Radical; Lipid Peroxidation; Male; Membrane Potential, Mitochondrial; Necrosis; Oxidation-Reduction; Oxidative Stress; Sperm Motility; Spermatozoa; Vitamin K 3

Similar to the leaves of P. Quinquefolius, American ginseng berry (AGB) is another important part of P. Quinquefolius with alternative therapeutic potential. The liver protection capabilities of the former have been demonstrated previously, however, the later has not yet been evaluated.. Based on our previous observation, the present work was designed to evaluate the hepatic protective effects for novel mechanisms of AGB in acetaminophen (APAP)-induced liver injury in vivo.. All mice were divided into four groups as follows: normal group, APAP group and APAP + AGB (150 mg/kg and 300 mg/kg) groups. AGB were orally administered for one week before exposure to APAP (250 mg/kg). Severe liver injury was observed and hepatotoxicity was evaluated after 24 h through evaluating the biochemical markers, protein expressions levels and liver histopathology.. Our study results clearly demonstrated that AGB pretreatment ameliorated APAP-induced hepatic injury as evidenced by decreasing plasma alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) compared to the APAP group. Western blotting analysis showed that pretreatment with AGB decreased the expressions levels of TNF-α and nuclear transcription factor-κB (NF-κB p65) in liver tissues. Meanwhile, the protein expression levels of caspases, cytochrome c, and Bax were elevated by AGB treatment for seven days, while the protein expression level of Bcl-2 was inhibited comparison with that in APAP group. Furthermore, supplement of AGB resulted in increase of superoxide dismutase (SOD) and glutathione (GSH), while decrease of malondialdehyde (MDA) content and the expression levels of 4-hydroxynonenal (4-HNE) and cytochrome P450 E1 (CYP2E1). The results of histopathological staining demonstrated that AGB pretreatment inhibited APAP-induced hepatocyte infiltration, congestion, and necrosis.. The present study demonstrated that AGB pretreatment protected liver cells against APAP-induced hepatotoxicity through inhibition of oxidative stress, inflammation responses via TNF-α-mediated caspase-3/-8/-9 signaling pathways.

Topics: Acetaminophen; Alanine Transaminase; Aldehydes; Animals; Aspartate Aminotransferases; Caspases; Chemical and Drug Induced Liver Injury; Cytochrome P-450 CYP2E1; Fruit; Glutathione; Interleukin-1beta; Liver; Male; Malondialdehyde; Mice; Necrosis; Oxidative Stress; Panax; Plant Extracts; Signal Transduction; Superoxide Dismutase; Transcription Factor RelA; Tumor Necrosis Factor-alpha

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

Acute liver injury is manifested by different degree of hepatocyte necrosis and may recover via the process of hepatocyte regeneration once the injury is discontinued. Most of the liver injury is associating with inflammatory cytokines. Resveratrol (RSV) is a natural phytoalexin with powerful anti-inflammatory effects.. The effects of RSV on cellular factors mediating liver damage and regeneration in acute carbon tetrachloride (CCl4 ) liver injury were investigated.. RSV decreased alanine aminotransferase, aspartate aminotransferase, necrosis, and 4-hydroxynonenal in the CCl4 -injured liver. RSV decreased hepatocyte apoptosis by reducing caspase 8 and caspase 3 but not Bax and Bcl-xL. RSV reduced Kupffer cells recruitment, the expressions of tumor necrosis factor-α and interleukin-6, but not interleukin-10. RSV lowered the numbers of anti-5-bromon-2'-deoxyuridine and anti-Ki67-positive hepatocytes. Hepatic hepatocyte growth factor, c-Met and transforming growth factor-α expressions were reduced by RSV, while transforming growth factor-β1 and hepatic stellate cells activation were not changed. RSV reduced the injury-induced CXCL10 elevations in serum and liver in vivo. Besides, RSV inhibited CXCL10 release from CCl4 -injured hepatocytes in vitro. In contrast, recombinant CXCL10 improved the viability of CCl4 -injured hepatocytes.. RSV therapy can be beneficial for acute toxic liver injury. RSV reduced hepatocyte apoptosis but limited hepatocyte regeneration possibly through reducing the hepatomitogenic signaling and the release of CXCL10.

Topics: Alanine Transaminase; Aldehydes; Animals; Anti-Inflammatory Agents; Apoptosis; Aspartate Aminotransferases; Carbon Tetrachloride; Caspase 3; Caspase 8; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Cytokines; Hepatocytes; Inflammation Mediators; Liver; Liver Regeneration; Male; Mice; Mice, Inbred C57BL; Necrosis; Phytoalexins; Phytotherapy; Resveratrol; Sesquiterpenes; Stilbenes

The aim of the study was to investigate the ameliorative effects and the mechanism of action of L-2-oxothiazolidine-4-carboxylate (OTC) on acetaminophen (APAP)-induced hepatotoxicity in mice. Mice were randomly divided into six groups: normal control group, APAP only treated group, APAP + 25 mg/kg OTC, APAP + 50 mg/kg OTC, APAP + 100 mg/kg OTC, and APAP + 100 mg/kg N-acetylcysteine (NAC) as a reference control group. OTC treatment significantly reduced serum alanine aminotransferase and aspartate aminotransferase levels in a dose dependent manner. OTC treatment was markedly increased glutathione (GSH) production and glutathione peroxidase (GSH-px) activity in a dose dependent manner. The contents of malondialdehyde and 4-hydroxynonenal in liver tissues were significantly decreased by administration of OTC and the inhibitory effect of OTC was similar to that of NAC. Moreover, OTC treatment on APAP-induced hepatotoxicity significantly reduced the formation of nitrotyrosin and terminal deoxynucleotidyl transferase dUTP nick end labeling positive areas of liver tissues in a dose dependent manner. Furthermore, the activity of caspase-3 in liver tissues was reduced by administration of OTC in a dose dependent manner. The ameliorative effects of OTC on APAP-induced liver damage in mice was similar to that of NAC. These results suggest that OTC has ameliorative effects on APAP-induced hepatotoxicity in mice through anti-oxidative stress and anti-apoptotic processes.

Topics: Acetaminophen; Alanine Transaminase; Aldehydes; Analgesics, Non-Narcotic; Animals; Antioxidants; Apoptosis; Aspartate Aminotransferases; Caspase 3; Chemical and Drug Induced Liver Injury; DNA Fragmentation; Glutathione; Glutathione Peroxidase; Liver; Male; Malondialdehyde; Mice; Mice, Inbred BALB C; Necrosis; Oxidative Stress; Pyrrolidonecarboxylic Acid; Thiazolidines; Tyrosine

Oxidative stress contributes to myonecrosis in the dystrophin-deficient fibers of mdx mice and in Duchenne's muscular dystrophy. We examined the effects of ascorbic acid (AA), an antioxidant and free radical scavenger, on the dystrophic diaphragm muscle.. Mdx mice (14 d old) received AA for 14 d. Control mdx mice received saline. The muscle damage was visualized by the penetration of Evans blue dye into myofibers and the extent of inflammation was assessed by histologic analysis. Creatine kinase levels were measured for the biochemical evaluation of muscle fiber degeneration. The levels of tumor necrosis factor-α (a proinflammatory cytokine) and 4-hydroxynonenal (a marker of lipid peroxidation) were analyzed by immunoblotting.. Ascorbic acid decreased creatine kinase levels, myonecrosis, inflammation, and the levels of tumor necrosis factor-α and 4-hydroxynonenal.. The present results suggest that AA plays a protective role in dystrophic muscle degeneration, possibly by decreasing reactive oxygen species, and support further investigations of AA as a potential therapy for dystrophinopathies.

Topics: Aldehydes; Animals; Antioxidants; Ascorbic Acid; Creatine Kinase; Diaphragm; Dystrophin; Female; Inflammation; Male; Mice; Mice, Inbred mdx; Muscle Fibers, Skeletal; Muscular Dystrophies; Necrosis; Oxidative Stress; Reactive Oxygen Species; Tumor Necrosis Factor-alpha

Lipid peroxidation is generally considered as primarily implicated in the pathogenesis of Alzheimer's disease (AD); one of its more reactive end products, 4-hydroxynonenal (HNE), has been shown to cause neuron dysfunction and degeneration. HNE production in the brain is stimulated by the amyloid-β peptide (Aβ), whose excessive accumulation in specific brain areas is a hallmark of AD. Conversely, Aβ production is up-regulated by this multifunctional aldehyde. Findings reported here point to the ability of HNE and Aβ to interact, with consequent potentiation of Aβ's cytotoxicity as determined in vitro using neuron-like cells derived from human dental-pulp progenitor cells. Preincubation of cells with the aldehyde markedly up-regulated Aβ uptake and intracellular accumulation, by overexpressing two of the three components of the plasma membrane multireceptor complex CD36/CD47/β1-integrin: experimental and clinical data indicate that intraneuronal accumulation of Aβ is an early event possibly playing a primary role in AD pathogenesis. That HNE-mediated overexpression of CD36 and β1-integrin, which plays a key role in HNE's potentiating Aβ neurotoxicity, in terms of necrosis, was confirmed when this effect was prevented by specific antibodies against the two receptors.

Topics: Adult; Aldehydes; Alzheimer Disease; Amyloid beta-Peptides; Antigens, Differentiation; Apoptosis; CD36 Antigens; CD47 Antigen; Cell Differentiation; Cell Nucleus Shape; Cell Shape; Cells, Cultured; Dental Pulp; Female; Gene Expression; Humans; Integrin beta1; L-Lactate Dehydrogenase; Lipid Peroxidation; Membrane Lipids; Necrosis; Neurons; Primary Cell Culture; Stem Cells; Up-Regulation

Oxidant stress is critically involved in various liver diseases. Superoxide formation causes c-Jun NH2-terminal kinase (JNK)- and caspase-dependent apoptosis in cultured hepatocytes. To verify these findings in vivo, male Fisher rats were treated with diquat and menadione. The oxidant stress induced by both compounds was confirmed by increased formation of glutathione disulfide and 4-hydroxynonenal protein adducts. Plasma alanine aminotransferase activities increased from 46+/-4 U/l in controls to 955+/-90 U/l at 6 h after diquat treatment. Hematoxylin and eosin staining of liver sections revealed large areas of necrotic cells at 3 and 6 h. DNA strandbreaks, evaluated with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, showed clusters of TUNEL-positive cells, where the staining was predominantly cytosolic and the cells were swollen, indicating oncotic necrosis. There was no significant increase in caspase-3 activities or relevant release of DNA fragments into the cytosol at any time between 0 and 6 h after diquat treatment. Despite the activation of JNK after high doses of diquat, the JNK inhibitor SP-600125 did not protect against diquat-induced necrosis. Menadione alone did not cause liver injury, but, in combination with phorone and FeSO4, induced moderate oncotic necrosis. On the other hand, if animals were treated with galactosamine/endotoxin as positive control for apoptosis, caspase-3 activities were increased by 259%, the number of TUNEL-positive cells with apoptotic morphology was increased 103-fold, and DNA fragmentation was enhanced 6-fold. The data indicate that liver cell death initiated by diquat-induced superoxide formation in vivo is mediated predominantly by oncotic necrosis and is independent of JNK activation.

Topics: Alanine Transaminase; Aldehydes; Animals; Antifibrinolytic Agents; Apoptosis; Caspases; Chemical and Drug Induced Liver Injury; Diquat; Disease Models, Animal; DNA Fragmentation; Endotoxins; Galactosamine; Glutathione Disulfide; Hepatocytes; In Situ Nick-End Labeling; JNK Mitogen-Activated Protein Kinases; Liver Diseases; Male; Necrosis; Oxidative Stress; Rats; Rats, Inbred F344; Superoxides; Vitamin K 3

Sustained activation of the c-Jun NH(2)-terminal kinase (JNK) signaling pathway mediates the development and progression of experimental diet-induced nonalcoholic fatty liver disease (NAFLD). Delineating the mechanism of JNK overactivation in the setting of a fatty liver is therefore essential to understanding the pathophysiology of NAFLD. Both human and experimental NAFLD are associated with oxidative stress and resultant lipid peroxidation, which have been proposed to mediate the progression of this disease from simple steatosis to steatohepatitis. The ability of oxidants and the lipid peroxidation product 4-hydroxynonenal (HNE) to activate JNK signaling suggested that these two factors may act synergistically to trigger JNK overactivation. The effect of HNE on hepatocyte injury and JNK activation was therefore examined in cells under chronic oxidant stress from overexpression of the prooxidant enzyme cytochrome P450 2E1 (CYP2E1), which occurs in NAFLD. CYP2E1-generated oxidant stress sensitized a rat hepatocyte cell line to death from normally nontoxic concentrations of HNE. CYP2E1-overexpressing cells underwent a more profound depletion of glutathione (GSH) in response to HNE secondary to decreased gamma-glutamylcysteine synthetase activity. GSH depletion led to overactivation of JNK/c-Jun signaling at the level of mitogen-activated protein kinase kinase 4 that induced cell death. Oxidant stress and the lipid peroxidation product HNE cause synergistic overactivation of the JNK/c-Jun signaling pathway in hepatocytes, demonstrating that HNE may not be just a passive biomarker of hepatic oxidant stress but rather an active mediator of hepatocellular injury through effects on JNK signaling.

Topics: Aldehydes; Animals; Apoptosis; Catalase; Cell Death; Cell Line, Transformed; Cytochrome P-450 CYP2E1; Extracellular Signal-Regulated MAP Kinases; Glutamate-Cysteine Ligase; Glutathione; Glutathione Transferase; Heat-Shock Response; Hepatocytes; Hydrogen Peroxide; JNK Mitogen-Activated Protein Kinases; Maleates; Malondialdehyde; MAP Kinase Kinase 4; Necrosis; Oxidative Stress; Phosphorylation; Proto-Oncogene Proteins c-jun; Rats; Reactive Oxygen Species; Signal Transduction; Transcription Factor AP-1; Transfection

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

Melatonin has marked antioxidant properties. The aim of the present study was to evaluate the therapeutic effect of melatonin on acute liver injury induced in rats by carbon tetrachloride (CCl4), allyl alcohol (AA) and their combination. A total of 108 male Wistar rats were divided into 12 experimental groups according to their treatment regimen (n = 5-10 rats in each group). Melatonin (100 mg/kg body weight, BW) was administered 6 hr (a) after a single dose of CCl4 (intragastrically 0. 66 mL/kg BW diluted 1:1 v/v with corn oil); (b) a single dose of AA (intraperitonealy, 0.62 mmol/kg BW 1:50 v/v in 0.9% saline solution); and (c) a combination of the above substances. Rats were sacrificed at 24 and 48 hr post-toxin administration and the therapeutic effect of melatonin was investigated by assessment of histopathological changes and lipid peroxidation alterations determined by measuring tissue malondialdehyde plus 4-hydroxy-nonenal (MDA + 4-HNE), plasma MDA and plasma levels of liver enzymes. The levels of a key antioxidant, glutathione (GSH), were measured in liver tissue homogenates. Hepatic necrosis was significantly reduced in the melatonin-treated rats 48 hr after administration of CCl4, AA and CCl4 + AA. The levels of hepatic enzymes in plasma were found to be significantly reduced at 24 and 48 hr in the CCl4 + AA treated rats after melatonin administration. Additionally, MDA and MDA + 4-HNE concentrations were significantly reduced at 24 and 48 hr time-points in all groups that received melatonin. GSH levels were decreased in liver after the toxic substances administration, whereas melatonin reversed this effect. In conclusion, a single dose of melatonin decreased hepatic injury induced by CCl4, AA and CCl4 + AA. The inhibition of the oxidative stress and therefore lipid peroxidation by melatonin in CCl4 and AA administered animals, may constitute the protective mechanism of melatonin against acute liver injury.

Topics: Alanine Transaminase; Aldehydes; Animals; Aspartate Aminotransferases; Carbon Tetrachloride Poisoning; Glutathione; Hepatocytes; L-Lactate Dehydrogenase; Liver; Male; Malondialdehyde; Melatonin; Mitosis; Necrosis; Propanols; Rats; Rats, Wistar

Reactive alpha,beta-unsaturated aldehydes are major components of common environmental pollutants and are products of lipid oxidation. Although these aldehydes have been demonstrated to induce apoptotic cell death in various cell types, we recently observed that the alpha,beta-unsaturated aldehyde acrolein (ACR) can inhibit constitutive apoptosis of polymorphonuclear neutrophils and thus potentially contribute to chronic inflammation. The present study was designed to investigate the biochemical mechanisms by which two representative alpha,beta-unsaturated aldehydes, ACR and 4-hydroxynonenal (HNE), regulate neutrophil apoptosis. Whereas low concentrations of either aldehyde (<10 microM) mildly promoted apoptosis in neutrophils (reflected by increased phosphatidylserine exposure, caspase-3 activation, and mitochondrial cytochrome c release), higher concentrations prevented critical features of apoptosis (caspase-3 activation, phosphatidylserine exposure) and caused delayed neutrophil cell death with characteristics of necrosis/oncosis. Inhibition of caspase-3 activation by either aldehyde occurred despite increases in mitochondrial cytochrome c release and occurred in close association with depletion of cellular GSH and with cysteine modifications within caspase-3. However, procaspase-3 processing was also prevented, because of inhibited activation of caspases-9 and -8 under similar conditions, suggesting that ACR (and to a lesser extent HNE) can inhibit both intrinsic (mitochondria dependent) and extrinsic mechanisms of neutrophil apoptosis at initial stages. Collectively, our results indicate that alpha,beta-unsaturated aldehydes can inhibit constitutive neutrophil apoptosis by common mechanisms, involving changes in cellular GSH status resulting in reduced activation of initiator caspases as well as inactivation of caspase-3 by modification of its critical cysteine residue.

Topics: Acrolein; Air Pollutants; Aldehydes; Apoptosis; Caspases; Cells, Cultured; Cysteine Proteinase Inhibitors; Cytochromes c; Enzyme Activation; Glutathione; Humans; Lipid Peroxidation; Mitochondria; Necrosis; Neutrophils; Phosphatidylserines

The effects of the dietary antioxidant N-acetylcysteine (NAC) on alcoholic liver damage were examined in a total enteral nutrition (TEN) model of ethanol toxicity in which liver pathology occurs in the absence of endotoxemia. Ethanol treatment resulted in steatosis, inflammatory infiltrates, occasional foci of necrosis, and elevated ALT in the absence of increased expression of the endotoxin receptor CD 14, a marker of Kupffer cell activation by LPS. In addition, ethanol treatment induced CYP 2 E1 and increased TNFalpha and TGFbeta mRNA expression accompanied by suppressed hepatic IL-4 mRNA expression. Ethanol treatment also resulted in the hepatic accumulation of malondialdehyde (MDA) and hydroxynonenal (HNE) protein adducts, decreased antioxidant capacity, and increased antibody titers toward serum hydroxyethyl radical (HER), MDA, and HNE adducts. NAC treatment increased cytosolic antioxidant capacity, abolished ethanol-induced lipid peroxidation, and inhibited the formation of antibodies toward HNE and HER adducts without interfering with CYP 2 E1 induction. NAC also decreased ethanol-induced ALT release and inflammation and prevented significant loss of hepatic GSH content. However, the improvement in necrosis score and reduction of TNFalpha mRNA elevation did not reach statistical significance. Although a direct correlation was observed among hepatic MDA and HNE adduct content and TNFalpha mRNA expression, inflammation, and necrosis scores, no correlation was observed between oxidative stress markers or TNFalpha and steatosis score. These data suggest that ethanol-induced oxidative stress can contribute to inflammation and liver injury even in the absence of Kupffer cell activation by endotoxemia.

Topics: Acetylcysteine; Aldehydes; Animals; Antioxidants; Cattle; Central Nervous System Depressants; Cytochrome P-450 CYP2E1; Cytokines; Cytosol; Enteral Nutrition; Ethanol; Glutathione; Immune System; Immunohistochemistry; Inflammation; Kupffer Cells; Lipid Peroxidation; Lipopolysaccharide Receptors; Lipopolysaccharides; Liver; Lymphotoxin-alpha; Male; Malondialdehyde; Necrosis; Oxidants; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Tumor Necrosis Factor-alpha

In this study we investigated the effect of insulin on neuronal viability and antioxidant defense mechanisms upon ascorbate/Fe2+-induced oxidative stress, using cultured cortical neurons. Insulin (0.1 and 10 microM) prevented the decrease in neuronal viability mediated by oxidative stress, decreasing both necrotic and apoptotic cell death. Moreover, insulin inhibited ascorbate/Fe2+-mediated lipid and protein oxidation, thus decreasing neuronal oxidative stress. Increased 4-hydroxynonenal (4-HNE) adducts on GLUT3 glucose transporters upon exposure to ascorbate/Fe2+ were also prevented by insulin, suggesting that this peptide can interfere with glucose metabolism. We further analyzed the influence of insulin on antioxidant defense mechanisms in the cortical neurons. Oxidative stress-induced decreases in intracellular uric acid and GSH/GSSG levels were largely prevented upon treatment with insulin. Inhibition of phosphatidylinositol-3-kinase (PI-3K) or mitogen-induced extracellular kinase (MEK) reversed the effect of insulin on uric acid and GSH/GSSG, suggesting the activation of insulin-mediated signaling pathways. Moreover, insulin stimulated glutathione reductase (GRed) and inhibited glutathione peroxidase (GPx) activities under oxidative stress conditions, further supporting that insulin neuroprotection was related to the modulation of the glutathione redox cycle. Thus, insulin may be useful in preventing oxidative stress-mediated injury that occurs in several neurodegenerative disorders.

Topics: Aldehydes; Animals; Apoptosis; Ascorbic Acid; Cell Survival; Cells, Cultured; Cerebral Cortex; Female; Ferrous Compounds; Glucose Transporter Type 3; Glutathione; Insulin; Lipid Peroxidation; Necrosis; Neurons; Oxidative Stress; Rats; Rats, Wistar; Stimulation, Chemical; Uric Acid

The mechanisms associated with cell death have been an important focus for neurobiology research. In the present study, the methodology of flow cytometry was used to optimize quantification of the toxic effects of tumor necrosis factor-alpha (TNF-alpha), trans-4-hydroxy-2-nonenal (4-HNE), and aged amyloid-beta (Abeta1-42) on rat primary cortical neurons. The fluorescent dyes annexin V-FITC and propidium iodide (PI) were used to identify populations of viable, early apoptotic, necrotic and late apoptotic cells by flow cytometry. Prior to exposure, the primary cultures showed 83% cell viability. Flow cytometry following labeling of cells with a specific neuronal marker, TUJ-1, revealed 82% pure neuronal populations, whereas approximately 7% were astrocytic as shown by glial fibrillary acidic protein positivity. Exposure of primary cultures to TNF-alpha, 4-HNE, and aged Abeta1-42 gave an increased number of early apoptotic cells. We show that flow cytometry is a suitable method for quantifying effects of different stressors on neurons in primary cultures. This technique could be useful for screening and testing of pharmacological compounds relevant to neurodegenerative disorders.

Topics: Aldehydes; Amyloid beta-Peptides; Animals; Apoptosis; Biomarkers; Cell Survival; Cells, Cultured; Cerebral Cortex; Disease Models, Animal; Flow Cytometry; Necrosis; Neurodegenerative Diseases; Neuroglia; Neurons; Neurotoxins; Oxidative Stress; Peptide Fragments; Rats; Rats, Sprague-Dawley; Tubulin; Tumor Necrosis Factor-alpha

Fatty liver caused by ethanol decreases survival after liver transplantation in rats. This study investigated if antioxidant polyphenols from Camellia sinenesis (green tea) prevent failure of fatty grafts from ethanol-treated rats. Donor rats were given ethanol intragastrically (6 g/kg). After 20 h, livers were explanted and stored in University of Wisconsin solution for 24 h. Prior to implantation, the explanted grafts were rinsed with lactated Ringer's solution containing 0 to 60 microg/ml polyphenols. Alanine aminotransferase (ALT) release after liver transplantation was 4.5-fold higher in recipients receiving ethanol-induced fatty grafts than in those receiving normal grafts. Liver grafts from ethanol-treated donors also developed severe focal necrosis. Graft survival was 11% in the ethanol group versus 88% for normal grafts. Polyphenol treatment at 60 microg/ml blunted ALT release by 66%, decreased necrotic areas by 84%, and increased survival to 75%. Ethanol increased alpha-(4-pyridyl-1-oxide)-N-tert.-butylnitrone free radical adducts in bile by 2.5-fold, as measured by electron spin resonance spectroscopy, and caused accumulation of 4-hydroxynonenal in liver sections, effects blunted by polyphenols. Epicatechin gallate, a major polyphenol from C. sinenesis, also decreased enzyme release, minimized pathological changes, and decreased free radical adduct formation. In conclusion, polyphenols scavenged free radicals in ethanol-induced fatty livers and decreased injury after liver transplantation.

Topics: Alanine Transaminase; Aldehydes; Animals; Antioxidants; Bile; Camellia; Catechin; Central Nervous System Depressants; Electron Spin Resonance Spectroscopy; Ethanol; Fatty Liver; Female; Flavonoids; Free Radical Scavengers; Free Radicals; Graft Survival; Liver Transplantation; Necrosis; Phenols; Polyphenols; Rats; Rats, Sprague-Dawley

Reactive oxygen radicals play an important role in various forms of liver injury. In this study, we evaluated the efficacy of edaravone, a newly synthesized free radical scavenger, in its clinical dosage on an experimental model of acute liver injury in rats.. The clinical dose of edaravone (3 mg/kg) was intravenously administered immediately and 3 h after intraperitoneal administration of carbon tetrachloride (CCl4) in rats. Histological evaluation including apoptosis and cytokine profiles were examined.. Fatty degeneration and necrosis with marked elevation of serum alanine aminotransferase and lactate dehydrogenase levels developed after CCl4 administration were significantly reduced by edaravone. In addition, the apoptotic index assessed by TUNEL method was significantly lowered in the edaravone treated group. Serum and liver transcription levels of interleukin-6, tumor necrosis factor-alpha, interleukin-4, and interleukin-10 were increased following CCl4 administration, and they were attenuated by edaravone treatment. The formation of malondialdehyde, 4-hydroxynonenal adduct and one of the markers for oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine, was also inhibited by edaravone treatment.. Edaravone has a remarkable protective effect on acute liver injury caused by oxygen radicals through not only attenuating the membrane lipid peroxidation, but also inhibiting the production of inflammatory cytokines. We theorize that edaravone may have a clinical benefit in the treatment of various liver injuries.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acute Disease; Alanine Transaminase; Aldehydes; Animals; Antipyrine; Apoptosis; Cell Death; Cytokines; Deoxyguanosine; Edaravone; Free Radical Scavengers; Growth Inhibitors; Immunohistochemistry; In Situ Nick-End Labeling; Interleukin-10; Interleukin-4; Interleukin-6; Liver; Male; Models, Chemical; Necrosis; Oxygen; Rats; Rats, Wistar; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Tumor Necrosis Factor-alpha

Carbon monoxide (CO) is the most popular cause of poisoning. The bilateral basal ganglia lesion characterizes the delayed neuronal cell death (DCD). We demonstrated there were both apoptosis and necrosis in the cortex, basal ganglia and hippocampus in a case of human CO accident. To elucidate the mechanism of DCD after CO inhalation, histological studies on the rat brain were conducted. Rats were ventilated with nitrous oxide (sham group), 10% O(2) (hypoxia group) or 1005 ppm CO (CO group) for 90 min, while the pericranial temperature was controlled at either 32, 37, or 39 degrees C during CO inhalation. After reoxygenation for 30 min, the rats were allowed to recover for 48 h. The ratio of eosinophilic and HNE-positive neurons in the cortex were higher in the CO group than in the hypoxia group at 37 degrees C, while the PaO(2) was much lower in the hypoxia than in the CO group. The damage was alleviated in the hypothermia (32 degrees C) as compared with normothermia, while the hyperthermia (39 degrees C) did not significantly increased it. CO inhalation injures neuron by reactive oxygen species (ROS), independent of hypoxia, as can be concluded from the histological comparison of DCD with HNE immunoreactivity.

Topics: Aldehydes; Animals; Apoptosis; Blood Pressure; Carbon Monoxide; Carbon Monoxide Poisoning; Cerebral Cortex; Heart Rate; Hypothermia, Induced; Immunohistochemistry; In Situ Nick-End Labeling; Male; Necrosis; Neurons; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species

Oxidants have been shown to be involved in alcohol-induced liver injury. This study was designed to determine whether cocoa flavonoid extract, composed mostly of epicatechin and epicatechin oligomers, protects against early alcohol-induced liver injury in rats. Male Wistar rats were fed high-fat liquid diets with or without ethanol (10-14 g/kg per day) and cocoa extract (400 mg/kg per day) continuously for 4 weeks using an enteral feeding protocol. Mean body weight gains ( approximately 4 g/day) were not significantly different between treatment groups. Cocoa extract did not affect average daily urine ethanol concentrations ( approximately 200mg/dL). After 4 weeks, serum alanine amino transferase levels of the ethanol group were increased nearly fourfold (110+/-16 IU/L) compared to control values (35+/-3 IU/L); this effect of ethanol was blocked by cocoa extract (60+/-6 IU/L). Additionally, enteral ethanol caused severe fat accumulation, mild inflammation, and necrosis in the liver; cocoa extract significantly blunted these changes. Increases in liver TNFalpha protein levels caused by ethanol were completely blocked by cocoa extract. Further, ethanol significantly increased the accumulation of protein adducts of 4-hydroxynonenal, a product of lipid peroxidation serving as an index of oxidative stress; again this was counteracted by the addition of cocoa extract. These results indicate that dietary flavanols such as those found in cocoa can prevent early alcohol-induced liver injury.

Topics: Alanine Transaminase; Aldehydes; Animals; Cacao; Catechin; Celiac Disease; Disease Models, Animal; Enteral Nutrition; Ethanol; Inflammation; Liver Diseases, Alcoholic; Necrosis; Phytotherapy; Plant Extracts; Proteins; Rats; Weight Gain

Four-hydroxynonenal (HNE) has been proposed as an important marker of radical-induced lipid peroxidation. The principal objective of this study was to assess the occurrence of lipid peroxidation in normal perinatal brain and brains with one form of pontosubicular neuronal necrosis (PSN). Immunochemical studies using an antibody against HNE-modified protein were performed in controls aged from 20 weeks of gestation to 64 years, and patients with PSN. Immunohistochemical study showed developmental and aging changes of positive staining in Purkinje cells and pontine neurons (27 weeks-7 months, 50 and 64 years). In addition, karyorrhectic cells in pontine nuclei with PSN were positively stained. Immunoblotting revealed that a 75-kDa protein, which is speculated to be mitochondrial complex-1 protein, was the most intensely expressed among multiple immunoreactive proteins. Our results identified the presence of oxidative stress in the perinatal neuron, and this oxidative stress may contribute to some forms of karyorrhectic death.

Topics: Adolescent; Aldehydes; Child; Child, Preschool; Gestational Age; Hippocampus; Humans; Infant; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Middle Aged; Necrosis; Pons; Purkinje Cells

The metabolism of CCl(4) initiates the peroxidation of polyunsaturated fatty acids producing alpha,beta-unsaturated aldehydes, such as 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA). The facile reactivity of these electrophilic aldehydic products suggests they play a role in the toxicity of compounds like CCl(4). To determine the rate at which CCl(4)-initiated lipid peroxidation results in the formation of 4-HNE and/or MDA hepatic protein adducts, rats were given an intragastric dose of CCl(4) (1.0 ml/kg) and euthanized 0-72 h after administration. Rabbit polyclonal antisera directed toward 4-HNE- or MDA-protein epitopes were employed in immuno-histochemical and immuno-precipitation/Western analyses to detect 4-HNE and MDA-protein adducts in paraffin-embedded liver sections and liver homogenates. As early as 6 h post CCl(4) exposure, 4-HNE and MDA adducts were detected immuno-histochemically in hepatocytes localized to zone 2 of the hepatic acinus. Liver injury was progressive to 24 h as lipid peroxidation and hepatocellular necrosis increased. The hallmark of CCl(4) hepatotoxicity, zone 3 necrosis, was observed 24 h after CCl(4) administration and immuno-positive hepatocytes were observed in zone 2 as well as zone 3. Immuno-positive cells were no longer visible by 36 to 72 h post CCl(4) administration. From 6 to 48 h after CCl(4) administration, at least four adducted proteins were immuno-precipitated from liver homogenates with the anti-MDA or anti-4HNE serum, which corresponded to molecular weights of 80, 150, 205, and greater than 205 kDa. These results demonstrate that 4-HNE and MDA alkylate specific hepatic proteins in a time-dependent manner, which appears to be associated with hepatocellular injury following CCl(4) exposure.

Topics: Alanine Transaminase; Aldehydes; Alkylation; Animals; Blotting, Western; Carbon Tetrachloride; Fatty Acids, Unsaturated; Immunohistochemistry; Lipid Peroxidation; Liver; Male; Malondialdehyde; Mineral Oil; Molecular Weight; Necrosis; Precipitin Tests; Proteins; Rats; Thiobarbituric Acid Reactive Substances; Time Factors

1,2-Dichlorobenzene (1,2-DCB) is a potent hepatotoxicant in male Fischer 344 (F344) rats and previous studies have suggested that reactive oxygen species may play a role in the development of hepatotoxicity. Since reactive oxygen species can damage lipid membranes, this study was conducted to determine the extent of lipid peroxidation after administration of 1,2-DCB by immuno-histochemical analysis of 4-hydroxynonenal (4-HNE) protein adduct formation in liver and conjugated diene formation in liver and serum. The contribution of Kupffer cells to the lipid peroxidation was also investigated. Male F344 rats were administered 1,2-DCB (3.6 mmol/kg i.p. in corn oil) and killed at selected times between 3 and 48 h. Time course studies revealed the greatest abundance of 4-HNE protein adducts in the centrilobular regions of the liver 24 h after 1,2-DCB administration, with much lower levels at 16 h. Adducts were present in necrotic and vacuolized centrilobular hepatocytes of 1,2-DCB treated rats but not in livers of controls. Further, conjugated dienes were significantly increased in liver and serum 16 and 24 h after 1,2-DCB administration, peaking at 24 h. These data correlated with hepatocellular injury, determined by serum alanine aminotransferase activity and histopathological evaluation, which was markedly elevated within 16 h and peaked at 24 h. When rats were pretreated with gadolinium chloride (GdCl3; 10 mg/kg i.v. 24 h prior to 1,2-DCB), an inhibitor of Kupffer cells, hepatotoxicity was decreased by 89 and 86%, at 16 and 24 h, respectively. Conjugated diene concentrations were decreased to control values at these times after 1,2-DCB administration. Moreover, no 4-HNE protein adducts were detected in livers of 1,2-DCB-treated rats pretreated with GdCl3. Finally, Kupffer cells isolated from 1,2-DCB-treated rats produced significantly more superoxide anion than Kupffer cells isolated from vehicle controls. These data, along with previous findings, suggest that lipid peroxidation associated with 1,2-DCB is mediated in part by Kupffer cell-derived reactive oxygen species.

Topics: Alanine Transaminase; Aldehydes; Animals; Anti-Inflammatory Agents; Chlorobenzenes; Cysteine Proteinase Inhibitors; Gadolinium; Immunohistochemistry; Insecticides; Kupffer Cells; Lipid Peroxidation; Liver; Male; Necrosis; Rats; Rats, Inbred F344; Reactive Oxygen Species; Vacuoles

Liver proteins form adducts with acetaldehyde and are modified by products of lipid peroxidation in alcohol-fed animals. It has been hypothesized that the formation of these modified liver proteins may contribute to liver injury in alcoholic liver disease. The present work was performed to determine the extent of protein modification in rats with experimental alcoholic liver disease. Rats were fed ethanol intragastrically with medium chain triglycerides (MCTs), palm oil, corn oil, or fish oil. The group fed MCTs and ethanol showed no liver injury, rats fed palm oil and ethanol showed only fatty liver, rats fed corn oil and ethanol showed fatty liver with moderate necrosis and inflammation, and rats fed fish oil and ethanol showed fatty liver with severe necrosis and inflammation. Antibodies were raised by using keyhole limpet hemocyanin modified in vitro by 4-hydroxynonenal (4-HNE) or acetaldehyde as immunogens. When liver extracts were examined by Western blot analysis, the intensities of the acetaldehyde-modified protein band (37 kd) in the alcohol-fed animals were significantly different among the ethanol-treated groups and correlated with plasma acetaldehyde concentrations. It was strongest in rats fed fish oil and ethanol, followed by rats fed palm oil and ethanol and rats fed corn oil and ethanol, whereas rats fed MCTs and ethanol showed the weakest intensity. The 37-kd protein-adetaldehyde adduct was located mainly in the pericentral region of the liver. No acetaldehyde adduct was detected in the control rats that were pair-fed with isocaloric amounts of dextrose. Western blot analysis using the anti-4-HNE antibody showed four distinctive bands (48, 45, 40, and 38 kd) in the liver extracts of alcohol-fed rats. Control animals showed only a weak 38-kd band. Although the intensities of the 48-, 40-, and 38-kd bands were similar among the different ethanol-treated groups, the intensity of the 45-kd band decreased from MCTs and ethanol > palm oil and ethanol > or = corn oil and ethanol > fish oil and ethanol. The data indicate that the degree of liver protein modification by acetaldehyde correlates well with the severity of liver injury in ethanol-fed rats, whereas modification by the lipid peroxidation product 4-HNE shows no correlation with the severity of liver injury.

Topics: Acetaldehyde; Aldehydes; Animals; Antibodies; Corn Oil; Dietary Fats; Fatty Liver; Fish Oils; Humans; Inflammation; Liver; Liver Diseases, Alcoholic; Male; Necrosis; Palm Oil; Plant Oils; Proteins; Rats; Rats, Wistar; Serum Albumin

Oxidative stress is known to cause apoptosis in many cell types, yet the mechanism of oxidative stress-induced apoptosis is not clear. Oxidative stress has been described to cause peroxidation of polyunsaturated fatty acids. 4-Hydroxynonenal (HNE) is a diffusible product of lipid peroxidation and has been shown to be toxic to cells. In this study, the effects of HNE on isolated alveolar macrophages (AM) from two murine strains (C3H/HeJ and C57BL/6J) were examined. HNE induced the formation of protein adducts in AMs from both strains of mice in a dose-dependent manner, and the amounts of HNE-protein adducts formed in cells from both strains were very similar. In the HNE dose range from 1 to 100 microM, AMs from both strains had very little necrosis as shown by trypan blue staining. However, AMs from both C3H/HeJ and C57BL/6J mice had extensive apoptosis at 100 microM HNE, but little or no apoptosis at 25 microM HNE. Furthermore, AMs from C57BL/6J mice had significant apoptosis at 50 microM HNE while AMs from C3H/HeJ mice had no significant apoptosis at this dose. At low doses of HNE (10 to 25 microM), there was induction of heme oxygenase 1. The data indicated that HNE induces apoptosis in murine macrophages, and cells from different strains of mice have different sensitivities to the HNE-induced apoptosis. The cause of the difference in susceptibility is not known, but it is possible that different stress response and/or apoptosis-regulating proteins may be in part responsible. Our observation that a product of lipid peroxidation causes apoptosis suggested that it might be a mediator for oxidative stress-induced apoptosis.

Topics: Aldehydes; Analysis of Variance; Animals; Apoptosis; Blotting, Western; Coloring Agents; Cross-Linking Reagents; DNA; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Lipid Peroxidation; Macrophages, Alveolar; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Necrosis; Oxidative Stress; Protein Binding; Proteins; Species Specificity; Trypan Blue

The pathogenesis of alcohol-induced liver disease involves the adverse effects of ethanol metabolites and oxidative tissue injury. Previous studies indicated that covalent protein adducts with reactive aldehydes may be formed in alcohol consumers. To study the role of such protein adducts in the development of liver injury, we examined the sequential appearances of adducts of the ethanol metabolite acetaldehyde (AA) and of two products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenol (HNE), in ethanol-fed micropigs. Immunohistochemical stainings using specific antibodies that recognize epitopes of each adduct were performed from liver biopsy specimens obtained at 1, 5, and 12 months from micropigs fed either control diet (n = 5) or ethanol-containing diets (n = 5). After 1 month on the ethanol diet, AA and MDA adducts were observed primarily in the perivenous regions co-localizing with each other and coinciding with increased concentrations of serum aminotransferase markers of liver injury. HNE adducts were usually less intense and more diffuse, and were also seen in some biopsy specimens from control animals. Although the most intense staining reactions at 5 months remained in zone 3, a more widespread distribution was usually seen together with increased evidence of steatonecrosis and focal inflammation. In terminal biopsies at 12 months, perivenous fibrosis was present in three of five biopsy specimens. More extensive pericentral and intralobular fibrosis was noted in one micropig fed ethanol for 21 months. These studies demonstrate that covalent adducts of proteins with reactive aldehydes are formed in early phases of alcohol-induced liver disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acetaldehyde; Aldehydes; Animals; Guinea Pigs; Immunohistochemistry; Lipid Peroxidation; Liver; Liver Cirrhosis, Experimental; Liver Diseases, Alcoholic; Male; Malondialdehyde; Necrosis; Rabbits; Swine; Swine, Miniature