8-epi-prostaglandin-f2alpha and Liver-Diseases--Alcoholic

To address the hypothesis that elevated blood alcohol increases systemic oxidant stress, we measured urinary excretion of isoprostanes (iPs), free radical-catalyzed products of arachidonic acid. Ten healthy volunteers received acute doses of alcohol (Everclear-R) or placebo under randomized, controlled, double-blind conditions. Urinary iPF2a-III increased in a time- and dosage-dependent manner after dosing with alcohol, with the peak urinary iPF2a-III excretion correlating with the rise in blood alcohol. To determine whether oxidant stress was associated with alcohol-induced liver disease (ALD), we then studied the excretion of iP in individuals with a documented history of alcohol-induced hepatitis or alcohol-induced chronic liver disease (AC). Both urinary iPF2a-III and urinary iPF2a-VI were markedly increased in patients with acute alcoholic hepatitis. In general, urinary iPF2a-III was significantly elevated in cirrhotic patients, relative to controls, but excretion was more pronounced when cirrhosis was induced by alcohol than by hepatitis C. Excretion of iPF2a-VI, as well as 4-hydroxynonenal and the iPF2a-III metabolite, 2,3-dinor-5, 6-dihydro-iPF2a-III, was also increased in AC. Vitamin C, but not aspirin, reduced urinary iPs in AC. Thus, vasoactive iPs, which serve as indices of oxidant stress, are elevated in the urine in both acute and chronic ALD. Increased generation of iPs by alcohol in healthy volunteers is consistent with the hypothesis that oxidant stress precedes and contributes to the evolution of ALD.

Topics: Adult; Aldehydes; Ascorbic Acid; Dinoprost; Double-Blind Method; Ethanol; F2-Isoprostanes; Female; Gas Chromatography-Mass Spectrometry; Humans; Lipid Peroxidation; Liver Diseases, Alcoholic; Male; Middle Aged

The variety of animal models used in the study of alcoholic liver disease reflects the formidable task of developing a model that replicates the human disease. We show that oral feeding of fatty acids derived from fish oil and ethanol induces fatty liver, necrosis, inflammation, and fibrosis. Together with the study of oxidative and nitrosative stress markers, cytokines, proteasome function, and protein studies, this model has provided an inexpensive and technically simple method of establishing pathological alcoholic liver injury.

Topics: Administration, Oral; Alanine Transaminase; Alcohol Drinking; Animals; Blotting, Western; Central Nervous System Depressants; Chymotrypsin; Cytochrome P-450 CYP2E1; Dinoprost; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Endotoxins; Ethanol; Fatty Acids; Fatty Liver, Alcoholic; Female; Immunohistochemistry; Liver; Liver Diseases, Alcoholic; Oxidative Stress; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Self Administration; Specimen Handling; Staining and Labeling; Thiobarbituric Acid Reactive Substances

In alcoholic liver disease (ALD), progression from initial steatosis, through hepatitis to cirrhosis is well described, resulting in 20,000 deaths in the UK annually. However, pathological mechanisms are not well understood and drug trials have led to conflicting results. It has been established that alcohol consumption increases hepatic free radical production and oxidant stress has been implicated in the disease process.. Markers of lipid peroxidation, antioxidant status, hepatic fibrogenesis, inflammation and liver function were measured in blood and urine from 24 patients with established alcoholic cirrhosis and in 49 age- and sex-matched controls.. In the ALD group, lipid peroxidation markers 8-isoprostane and malondialdehyde were significantly increased (p<0.001), as was the ratio of oxidized to reduced glutathione (p=0.027). The antioxidants selenium, glutathione (whole blood and plasma) and vitamins A, C and E were all significantly decreased (p<0.001); median plasma glutathione levels were only 19% of control levels. Type III procollagen peptide (PIIINP), a serum marker of hepatic fibrogenesis, and C-reactive protein (CRP) were both increased (p<0.001). Urinary 8-isoprostane correlated positively with PIIINP, CRP and markers of cholestasis (alkaline phosphatase and bilirubin) and negatively with glutathione (whole blood), vitamins A and E and albumin.. Oxidant stress, as reflected in blood and urine by a wide range of pro- and antioxidant markers, is a significant feature of alcoholic cirrhosis, providing a mechanism by which alcohol intake may be linked to hepatic inflammation and fibrosis. Non-invasive markers could prove valuable in monitoring response to treatment during clinical trials.

Topics: Adult; Aged; Antioxidants; Biomarkers; C-Reactive Protein; Dinoprost; Enzyme-Linked Immunosorbent Assay; Female; Humans; Liver Diseases, Alcoholic; Male; Middle Aged; Oxidative Stress; Peptide Fragments; Procollagen; Prognosis; Severity of Illness Index

F2-isoprostanes (F2-IP) and 4-hydroxynonenal (4-HNE), peroxidation products of polyunsaturated fatty acids (PUFA), are considered the most reliable indicators of endogenous lipid peroxidation in vivo. To determine to what extent these are also altered in patients with alcoholic liver disease, plasma free and esterified F2-IP as well as 4-HNE were measured by GC/MS in 49 fasting subjects who underwent diagnostic percutaneous needle biopsies of the liver. Compared to patients with mild steatosis and no fibrosis, free F2-IP and 4-HNE were strikingly increased in individuals with alcoholic hepatitis. There was also a significant but lesser rise of 4-HNE in patients with perivenular fibrosis. An increase of F2-IP was also found in subjects with transition to, or complete, alcoholic cirrhosis, with a comparable trend for 4-HNE. By contrast, in patients who were drinking heavily up to 48 hr before admission, F2-IP were not abnormal, but they increased later (p < 0.005). Contrasting with plasma free F2-IP, esterified F2-IP were not significantly changed with fibrosis. Thus, whereas circulating esterified F2-IP were unchanged in patients with alcoholic liver disease, there was an increase in free F2-IP as well as 4-HNE during recovery from intoxication. The increase was not a result of accompanying hepatitis C but a function of the stage of alcoholic liver injury, possibly reflecting enhanced lipid peroxidation as well as interference with biliary excretion and/or hepatic esterification.

Topics: Aldehydes; Cysteine Proteinase Inhibitors; Dinoprost; F2-Isoprostanes; Gas Chromatography-Mass Spectrometry; Hepatitis, Alcoholic; Humans; Lipid Peroxidation; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases, Alcoholic; Male; Predictive Value of Tests

We used the intragastric feeding rat model for alcoholic liver disease to investigate the relationship between pathological severity and lipid peroxidation. Lipid peroxidation was assessed by measurement, in plasma, of a novel noncyclooxygenase-derived prostanoid (8-isoprostane). Six groups of animals fed ethanol and different dietary fats (saturated fat, corn oil and fish oil) were sacrificed at 1 month. Histological liver examination, plasma measurements of 8-isoprostane and measurements of microsomal conjugated dienes were carried out. Animals fed fish oil and ethanol developed the most severe liver injury and had the highest 8-isoprostane levels in plasma (919 +/- 112 pg/ml). These levels were significantly higher than the levels seen in the corn oil-ethanol (498 +/- 105 pg/ml) (P < 0.02) and saturated fat-ethanol (28.6 +/- 11.8 pg/ml) (P < .001) groups. Rats fed saturated fat and dextrose and corn oil and dextrose had levels of < 20 pg/ml. However rats fed fish oil and dextrose had, on average, 8-isoprostane levels about 100-fold higher than those seen in the saturated fat-dextrose and corn oil-dextrose groups. A significant correlation between pathological severity and plasma 8-isoprostane levels was seen in the fish oil (r = 0.92, P < .001) and non-fish oil-treated groups (r = 0.94, P < .001). A significant correlation also was seen between 8-isoprostane levels and liver microsomal conjugated dienes (r = 0.93, P < .001). Our results provide strong support for the hypothesis that lipid peroxidation in ethanol-fed rats contributes to pathological liver injury.

Topics: Animals; Arachidonic Acids; Cytochrome P-450 Enzyme System; Dinoprost; F2-Isoprostanes; Lipid Peroxidation; Liver; Liver Diseases, Alcoholic; Male; Rats; Rats, Wistar

Cytochrome P450 induction is believed to be important in the pathogenesis of alcoholic hepatic disease. Because cimetidine is a general inhibitor of cytochrome P450 enzymes, it was hypothesized that it could be useful in preventing alcoholic hepatic injury. An intragastric feeding model was used these studies. Experimental animals were divided into groups of four to five rats/group and fed the following diets: corn oil+dextrose, corn oil+ethanol (CE) and corn oil+ethanol+cimetidine (250 mg kg-1 day-1) (CEC). The rats in each group were sacrificed at the following time intervals: 2 weeks, 1 month and 2 months. For each animal, the severity of the pathologic findings and relative protein levels of cytochromes P450 2E1, 2B and 4A were measured. In addition, plasma levels of thromboxane B2, 6-ketoprostaglandin F1 alpha and 8-isoprostane were also measured. The most significant finding was that cimetidine completely prevented alcoholic hepatic injury in this model system. The pathologic scores (an indication of the severity of injury) were significantly lower in the CEC groups compared with the CE group. There was however, no significant difference in cytochrome P450 2E1, 2B or 4A protein levels between CE and CEC groups. Thromboxane B2 and 8-isoprostane levels were significantly lower and 6-ketoprostaglandin F1 alpha, significantly higher in the CEC group than in the CE group. These results indicate that possible mechanisms involved in the protective action of cimetidine include inhibition of thromboxane production and lipid peroxidation.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Arachidonic Acid; Arachidonic Acids; Cimetidine; Cytochrome P-450 Enzyme System; Dinoprost; Disease Models, Animal; Endotoxins; F2-Isoprostanes; Lipid Peroxidation; Liver Diseases, Alcoholic; Male; Rats; Rats, Wistar; Thromboxane B2