Evidence for lipid peroxidation in endotoxin-poisoned mice.

Ethane has been identified and quantitated in air exhaled by mice following intraperitoneal injection of 20, 40, or 200 mg of Escherichia coli O111:B4 lipopolysaccharide (LPS) per kg. Significant increases in ethane concentration occurred within 1 to 5 h after LPS administration. In addition, increased concentrations of malondialdehyde were found in crude homogenates of livers obtained from mice 16 h after administration of 20 mg of LPS per kg. These results suggest that lipid peroxidation may be an important mechanism responsible for LPS toxicity.     

Increased hepatic lipid peroxidation in aged mice

In recent years, the free radical theory of aging has attained great interest. Many studies on aging using tissue homogenates and subcellular fractions have provided evidence for the occurrence of lipid peroxidation. However, there are studies which report decrease or no significant change in parameters of lipid peroxidation. In our study, we investigated whether hepatic lipid peroxidation levels in male Swiss-Albino mice change with age. Three groups of animals, 3, 6 and 18 months old, were used. The diene conjugate and malondialdehyde levels of liver homogenates, mitochondria and microsomes were measured. Significant increases in both diene conjugate and malondialdehyde levels of liver homogenates and mitochondria have been observed in 18-month-old mice when compared with those aged 3 and 6 months. As for microsomes, only malondialdehyde levels were elevated in the old group when compared with young and adult groups. Both parameters were significantly increased in aged mice which indicate that lipid peroxidation is important in advancing age in mice.     

Superoxide dismutase, catalase and lipid peroxidation in liver of young mice of different ages

The lipid peroxidation and activities of main enzymes involved in the peroxide metabolism were measured at resting conditions and after completion of a 2-month treatment with H2O2. At the start of the experiments 1- and 3-month-old female BALB/c mice received either a high dose of H2O2 (0.5% H2O2 in drinking water; intake 12.5 x 10(-3) g/day/mouse) or a low dose of H2O2 (0.5 ml of 0.5% H2O2 by esophageal canula on every alternate day; intake 1.0 x 10(-3) g/day/mouse). The following conclusions can be drawn: a relative higher increase in activity of catalase could be induced at the age of 3 months than at the age of 5 months by a high dose of H2O2. The activity of superoxide dismutase (SOD) was not changed by a high dose of H2O2. A moderate increase in the activity of catalase and a remarkable decrease in SOD-activity resulted from a low-dose H2O2 treatment at the age of 5 months. The level of lipid peroxidation was increased by the low-dose and not influenced by the high-dose H2O2 treatment in 5-month-old-mice.     

Kinetics of lipid peroxidation in the isolated surviving rat liver

The kinetics of accumulation of lipid peroxidation products (primary products, hydroperoxides; secondary products, malonic dialdehyde and fluorescent pigments) in the isolated unperfused and previously perfused liver was investigated during aerobic incubation. During survival intensive accumulation of primary, secondary, and end products of lipid peroxidation was shown to take place, and its kinetics is extremal in character. The velocity of this process in the unperfused liver is much higher than in the previously perfused liver.Laboratory of Biophysics of Reception, A. I. Karaev Institute of Physiology, Academy of Sciences of the Azerbaidzhan SSR. (Presented by Academician of the Academy of Sciences of the Azerbaidzhan SSR G. G. Gasanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 11, pp. 548–551, November, 1979.     

Genetic differences in hepatic lipid peroxidation potential and iron levels in mice.

Oxidative damage to macromolecules, including lipids, has been hypothesized as a mechanism of aging. One end product of lipid peroxidation, malondialdehyde (MDA), is often quantified as a measure of oxidative damage to lipids. We used a commercial colorimetric assay for MDA (Bioxytech LPO-586, Oxis International, Portland, OR) to measure lipid peroxidation potential in liver tissue from young (2 month) male mice from recombinant inbred (RI) mouse strains from the C57BL/6J (B6)xDBA/2J (D2) series (BXD). The LPO-586 assay (LPO) reliably detected significant differences (P<0.0001) in lipid peroxidation potential between the B6 and D2 parental strains, and yielded a more than two-fold variation across the BXD RI strains. In both B6 and D2 mice, LPO results were greater in old (23 month) mice, with a larger age-related increase in the D2 strain. As the level of iron can influence lipid peroxidation, we also measured hepatic non-heme iron levels in the same strains. Although iron level exhibited a slightly negative overall correlation (r(2)=0.119) with LPO results among the entire group of BXD RI strains, a sub-group with lower LPO values were highly correlated (r(2)=0.704). LPO results were also positively correlated with iron levels from a group of 8 other inbred mouse strains (r(2)=0.563). The BXD RI LPO data were statistically analyzed to nominate quantitaive trait loci (QTL). A single marker, Zfp4, which maps to 55.2 cM on chromosome 8, achieved a significance level of P<0.0006. At least two potentially relevant candidate genes reside close to this chromosomal position. Hepatic lipid peroxidation potential appears to be a strain related trait in mice that is amenable to QTL analysis.     

Immunohistochemical detection of the lipid peroxidation product 4-hydroxynonenal after experimental brain injury in the rat.

This study examined the accumulation of the cytotoxic lipid peroxidation product 4-hydroxynonenal (HNE) after lateral fluid percussion (FP) brain injury in rats. A diffuse distribution of HNE-immunoreactivity (HNE-ir) was observed in the cortex and hippocampus of the ipsilateral, but not of the contralateral, hemisphere at 30 min, 6 h, 24 h, and 48 h after brain injury. The HNE-ir was well-localized in cell bodies of the ipsilateral cortex and the CA3 pyramidal layer in the ipsilateral hippocampus. Because HNE's interaction with certain proteins causes protein dysfunction and HNE, in vitro, causes neuronal cell damage, the present results suggest that HNE's interaction with neuronal proteins may contribute to neuronal damage in the ipsilateral cortex and hippocampus after brain injury.     

Relationship between oxygen anion-radical generation and lipid peroxidation in liver microsomes

Determination of the O₂ consumption and accumulation of malondialdehyde, induced by phenobarbital and 3-methylcholanthrene in rat or rabbit liver microsomes revealed inhibition of lipid peroxidation but a relatively high level of O₂ ^?-radical generation. It is postulated that the absence of direct correlation between lipid peroxidation activity and O₂ ^? generation in microsomes depends on the antioxidant level in the microsomal membrane.     

Carbon tetrachloride-mediated lipid peroxidation induces early mitochondrial alterations in mouse liver

Although carbon tetrachloride (CCl(4))-induced acute and chronic hepatotoxicity have been extensively studied, little is known about the very early in vivo effects of this organic solvent on oxidative stress and mitochondrial function. In this study, mice were treated with CCl(4) (1.5?ml/kg ie 2.38?g/kg) and parameters related to liver damage, lipid peroxidation, stress/defense and mitochondria were studied 3?h later. Some CCl(4)-intoxicated mice were also pretreated with the cytochrome P450 2E1 inhibitor diethyldithiocarbamate or the antioxidants Trolox C and dehydroepiandrosterone. CCl(4) induced a moderate elevation of aminotransferases, swelling of centrilobular hepatocytes, lipid peroxidation, reduction of cytochrome P4502E1 mRNA levels and a massive increase in mRNA expression of heme oxygenase-1 and heat shock protein 70. Moreover, CCl(4) intoxication induced a severe decrease of mitochondrial respiratory chain complex IV activity, mitochondrial DNA depletion and damage as well as ultrastructural alterations. Whereas DDTC totally or partially prevented all these hepatic toxic events, both antioxidants protected only against liver lipid peroxidation and mitochondrial damage. Taken together, our results suggest that lipid peroxidation is primarily implicated in CCl(4)-induced early mitochondrial injury. However, lipid peroxidation-independent mechanisms seem to be involved in CCl(4)-induced early hepatocyte swelling and changes in expression of stress/defense-related genes. Antioxidant therapy may not be an efficient strategy to block early liver damage after CCl(4) intoxication.     

Micellar electrokinetic chromatography separation and laser-induced fluorescence detection of the lipid peroxidation product 4-hydroxynonenal.

4-Hydroxnonenal (HNE) is a product of lipid peroxidation in biological systems that causes a variety of harmful biological effects. A method for identifying HNE based on derivatization with the fluorescent reagent dansylhydrazine (5-(dimethylamino)naphthalene-1-sulphonehydrazine (DNSH) followed by micellar electrokinetic chromatography separation laser-induced fluorescence detection has been developed. The derivatization reaction has also been investigated for significant experimental parameters and rat brain homogenates with induced lipid peroxidation have been analysed for HNE contents. The limit of detection (3 S/N) was 30 nM or 0.3 fmol in the injected sample.     

In situ detection of lipid peroxidation in chronic hepatitis C: correlation with pathological features.

AIMS: To assess the occurrence of lipid peroxidation in chronic hepatitis C and to evaluate its relation to pathological features and liver iron concentrations. METHODS: Liver biopsy samples of 43 patients with untreated chronic hepatitis C were studied by immunohistochemistry using specific antibodies directed against two major aldehyde metabolites of lipid peroxidation, malondialdehyde (MDA), and 4-hydroxynonenal (HNE). RESULTS: MDA and HNE adducts (aldehydes covalently linked to another molecule) were detected in the liver samples in 77% and 30% of cases, respectively. MDA adducts were detected both in the extracellular matrix and sinusoidal cells localised in areas of periportal and lobular necrosis. HNE adducts appeared in the cytoplasm of only a few hepatocytes. Comparison of the semiquantitative assessment of adducts (MDA and HNE indexes) with the grading and the staging of chronic hepatitis showed that the MDA index was correlated with fibrosis score (p < 0.001) and the grade of activity (p < 0.01). There was also a tendency to correlation with liver iron concentration (p = 0.09). No correlation was observed between the HNE index and pathological features or liver iron concentration. CONCLUSION: Lipid peroxidation products are detectable in the liver of chronic hepatitis C patients. The presence of MDA adducts in areas of active fibrogenesis and the correlation between the MDA index and fibrosis score suggest a role for lipid peroxidation in liver fibrosis.     

Activity of antioxidant enzymes and lipid peroxidation in intact and mutagen-treated NZW mice

Catalase and superoxide dismutase activities in the liver of NZW mice are 29.3 μmol H₂O₂/min×mg protein and 10.6 U/mg protein, respectively. The rate of accumulation of lipid peroxidation (LPO) products is low within the first 60 min of incubation of liver homogenates with ascorbate and then rapidly increases. A similar process is observed with Fe+ascorbate system, where LPO rate is markedly higher and lag-period lasts 10 min. Under the action of cyclophosphane the activity of catalase increases by 32%, while that of superoxide dismutase decreases by 46%, which is accompanied by a decline in the sensitivity of liver tissue to LPO induction. When LPO is inducedin vitro by ascorbate, lag-period decreases 2-fold, while the rate of accumulation of LPO products increases by 38% and their maximum level by 35% compared with the control. Similar processes develop in the Fe+ascorbate system. Dioxydine induces no significant changes in the activities of catalase and superoxide dismutase as well as in LPO product accumulation in the ascorbate and Fe+ascorbate systems. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 4, pp. 381–384, April, 1997