Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to test the hypothesis that deprivation of enteral feeding contributes to the development of total parenteral nutrition (TPN)-induced hepatic dysfunction and that alterations of gut hormones are involved in its pathogenesis. Twenty-one adult Sprague-Dawley rats were randomized into three groups: group 1 received chow feeding ad libitum (288 kcal/kg per day); group 2 received dextrose-based TPN (320 +/- 5 kcal/kg per day); and group 3 received TPN (315 +/- 15 kcal/kg per day) plus chow feeding ad libitum (74 +/- 1 kcal/kg per day). After 7 days, portal blood was assayed for insulin, glucagon, gastrin, peptide YY, secretin, and vasoactive intestinal polypeptide; systemic blood for determination of liver function tests and serum lipid analysis. Liver biopsies were taken for histology and staining for fat, and the remainder of the livers were removed for tissue lipid analysis. TPN induced striking hepatic steatosis with prominent histologic changes and accumulation of lipids, mainly triglycerides and cholesterol ester, in the liver. Addition of enteral feeding to TPN-treated animals significantly reduced the histologic changes as well as lipid accumulation in the liver. Portal plasma levels of gastrin and peptide YY were reduced in animals maintained on TPN alone, with no change in secretin or vasoactive intestinal polypeptide levels. Enteral supplementation increased peptide YY levels in group 3, but not to normal, while gastrin secretion remained decreased. The serum triglyceride levels were decreased in both TPN groups; no differences were detected in the serum cholesterol levels or liver function tests.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of enteral feeding on hepatic steatosis induced by total parenteral nutrition. 816 98

Lipid peroxidation may be important in the pathogenesis of alcoholic liver injury. We investigated the potential of medium chain triglycerides and vitamin E to decrease lipid peroxidation and reverse established alcoholic liver injury. Four groups (five rats/group) of male Wistar rats were studied. Rats in group 1 were fed a fish oil-ethanol diet for 6 weeks. Rats in groups 2, 3 and 4 were fed the fish oil-ethanol diet for 6 weeks before being switched to fish oil-dextrose (group 2), fish oil-dextrose plus vitamin E (group 3) or medium chain triglycerides-dextrose (group 4) diets for 2 weeks. Liver samples were analyzed for histopathology, lipid peroxidation, fatty acid composition and cytochrome P450 2E1 activity. By 6 weeks, all rats developed fatty liver, inflammation and necrosis. After switching to the dextrose-containing diets, there was minimal histologic improvement in group 2, moderate improvement in group 3 and near normalization of the histology in group 4. Histologic improvement was associated with decreased lipid peroxidation and cytochrome P450 2E1 activity. Higher levels of polyunsaturated fatty acids were seen in groups 2 and 3 than in group 4. Our results indicate that a diet enriched in saturated (group 4) but not polyunsaturated (group 2) fatty acids effectively reverses alcoholic liver injury. Treatment with vitamin E also led to histologic improvement. These effects may be explained, at least in part, by down-regulation of lipid peroxidation. Other effects of medium chain triglycerides, such as their propensity for oxidation rather than esterification, may also be important.
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PMID:Medium chain triglycerides and vitamin E reduce the severity of established experimental alcoholic liver disease. 866 40

We used the intragastric feeding rat model for alcoholic liver disease to investigate the relationship between transforming growth factor (TGF)-beta 1 and inhibition of endothelial cell proliferation. Twelve groups of male Wistar rats (four to five rats per group) were fed ethanol or dextrose with either corn oil or saturated fat for 1-, 2-, and 4-week periods. All control animals were pair fed the same diets as ethanol-fed rats except that ethanol was isocalorically replaced by dextrose. In the ethanol-fed groups, nonparenchymal cells were isolated and TGF-beta 1 was measured in the nonparenchymal cell supernatant. Liver pathology and endothelial cell proliferation with an antibody to proliferating cell nuclear antigen were studied in all groups. Plasma TGF-beta 1 was measured in all rats. Pathological changes (fatty liver, necrosis, and inflammation) were observed only in the corn oil/ethanol-fed rats at 4 weeks. Significantly higher levels of TGF-beta 1 were seen in both plasma and nonparenchymal cell supernatant in rats fed corn oil and ethanol; plasma levels of TGF-beta 1 were not significantly different between the dextrose-fed controls and saturated fat/ethanol-fed rats. A significant inverse correlation (r = -0.89, P < 0.01) was seen between plasma TGF-beta 1 and the number of endothelial cells arrested at G1/S. Immunohistochemistry revealed the presence of TGF-beta 1 staining in interstitial macrophages only in rats fed corn oil and ethanol. The present study provides evidence for a role for TGF-beta 1 in inhibiting endothelial cell proliferation in experimental alcoholic liver disease. Arrest of endothelial cells may lead to their differentiation and/or to produce mediators that could stimulate other cells such as Ito cells. Sustained TGF-beta 1 may also lead to Ito cell production of extracellular matrix.
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PMID:Role of transforming growth factor-[beta]1 in inhibiting endothelial cell proliferation in experimental alcoholic liver disease. 877 30

We investigated whether alcohol pretreatment sufficient to cause fatty liver change would affect the disposition of bupivacaine after i.v. administration in pigs. Twelve male pigs (22-26 kg) were randomly divided into two groups of six each. Group A received ethanol (1 g kg-1 day-1) via an intragastric tube for 16 days. Group D received an equal volume of isocaloric dextrose 44% in water for this period. On day 17, left internal jugular and carotid cannulae were placed under thiopentone anaesthesia. On recovery from anesthesia, a blood sample was taken for the determination of liver function indices and then bupivacaine hydrochloride (1.2 mg kg-1) was administered over one minute and samples for plasma bupivacaine analysis taken from the arterial cannulae over the next five hours. Right liver lobe biopsies were taken and animals were killed under general anaesthesia. Blind evaluation of liver biopsies confirmed fatty liver changes only in alcohol-pretreated livers. Despite this there were no differences in bupivacaine disposition and liver function indices between the two groups.
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PMID:Alcohol pretreatment does not affect bupivacaine pharmacokinetics in the pig. 893 23

Liver lipid peroxidation, nonheme iron, antioxidants, and protein oxidation were investigated in experimental alcohol-induced liver disease in the rat. Wistar male rats were intragastrically and continuously infused for 4 weeks with a high-fat diet plus an ethanol or an isocaloric amount of dextrose, maintaining a high blood alcohol level (200-300 mg%). This model induced fatty liver, spotty necrosis, and focal inflammation. This pathology was associated with an enhanced lipid peroxidation and a decrease in the major antioxidant factors. Hepatic alpha-tocopherol and glutathione concentrations were significantly decreased in ethanol-fed rats. Glutathione peroxidase (GPx) was also decreased, whereas glutathione S-transferase (GST) was unaffected. The nonheme iron level was significantly decreased. Protein oxidation was assessed through three parameters: protein thiols, protein carbonyl groups, and the activity of glutamine synthetase (GS), a centrilobular enzyme particularly susceptible to free-radical-mediated damage. Ethanol-fed rats had decreased protein thiol concentrations and reduced GS activity, together with increased protein carbonyls. A significant correlation between GS activity and the pathological score was observed. This study confirms the ethanol-related increase in lipid peroxidation and shows that ethanol impairs the hepatic antioxidant potential. Furthermore, evidence of oxidative protein damage is given, including decreased activity of a key enzyme of ammonia metabolism. These protein disturbances may contribute to the pathogenesis of the observed liver damage.
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PMID:Effect of chronic ethanol feeding on lipid peroxidation and protein oxidation in relation to liver pathology. 902 46

We studied the effect of the long-acting parenteral iron chelator, hydroxyethyl starch deferoxamine (HES-DFO) on liver nonheme iron, lipid peroxidation and pathologic changes in the liver in the intragastric feeding rat model for alcoholic liver disease. Male Wistar rats (225-250 g) were fed liquid diet and ethanol for 2 months. In control pair-fed animals, ethanol was isocalorically replaced by dextrose. Two additional groups of animals (dextrose and ethanol fed) received HES-DFO (25 mg deferoxamine equivalents/kg, three times a week). The blood ethanol level in the ethanol-fed animals was maintained between 150 and 350 mg/dl. For each animal, the levels of hepatic nonheme iron, lipid peroxidation and pathologic changes were evaluated. Ethanol administration caused fatty liver, necrosis and inflammation. Addition of HES-DFO to the ethanol diet increased the severity of pathologic changes, particularly necrosis and inflammation. The nonheme iron in alcohol-fed animals was significantly higher (18.3 +/- 4.3 microg liver) than in pair-fed dextrose controls (12.5 +/- 1.5 microg, P < .05). Addition of HES-DFO significantly increased nonheme iron levels in the dextrose-fed rats (17.1 +/- 2.0 microg/g, P < .02) but not in ethanol-fed rats (20.0 +/- 2.0). Ethanol increased levels of conjugated dienes; these levels were not altered by HES-DFO. The most significant observations in this study were: 1) the higher hepatic nonheme iron content in ethanol-fed rats compared with pair-fed dextrose controls; 2) the absence of changes in hepatic nonheme iron levels or lipid peroxidation in ethanol-fed groups treated with HES-DFO; and 3) the worsening of liver injury in ethanol-fed rats by HES-DFO.
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PMID:The long-acting parenteral iron chelator, hydroxyethyl starch-deferoxamine, fails to protect against alcohol-induced liver injury in rats. 902 21

Based on studies that show a role for the low-density lipoprotein (LDL)-receptor in arachidonic acid delivery and eicosanoid synthesis in macrophages, the present study investigated the effect of cholesterol supplementation on pathological changes and thromboxane (TX) synthesis in alcoholic liver injury. Male Wistar rats were intragastrically fed ethanol with either corn oil or fish oil for 1 month. Control rats received isocaloric amounts of dextrose instead of ethanol. An additional group of rats fed either ethanol or dextrose with fish oil or corn oil were supplemented with 1% cholesterol. At the time of killing, all rats had the following evaluated: liver histopathology, lipid peroxidation, liver and plasma thromboxane levels, plasma endotoxin and messenger RNA (mRNA) levels of LDL-receptor, tumor necrosis factor alpha (TNF-alpha), cyclooxygenase (Cox)-1 and -2, and transforming growth factor beta (TGF-beta). Rats fed ethanol with either fish oil or corn oil developed fatty liver, necrosis, inflammation, and central vein collagen deposition. Cholesterol supplementation enhanced the degree of fibrosis but prevented necrosis and inflammation. These alterations in pathological changes by cholesterol were accompanied by absent TNF-alpha and Cox-2 mRNAs, decreased thromboxane levels, decreased lipid peroxidation, and increased TGF-beta mRNA. Cholesterol enrichment of the diet thus decreases proinflammatory components, but enhances fibrosis in ethanol-fed rats.
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PMID:Cholesterol supplementation prevents necrosis and inflammation but enhances fibrosis in alcoholic liver disease in the rat. 921 56

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.
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PMID:Acetaldehyde-modified and 4-hydroxynonenal-modified proteins in the livers of rats with alcoholic liver disease. 930 95

We investigated the potential of 16-desmethyl tirilazad mesylate, a member of 21-aminosteroids, to ameliorate alcohol-induced liver injury. Four groups (five rats/group) of male Wistar rats were studied. One group of rats was fed fish oil and ethanol (FE) for 4 weeks, and a second group received isocaloric amounts of dextrose instead of ethanol (FD). The third (FE-LAZ) and fourth (FD-LAZ) groups received the addition of 10 mg/kg/day of 16-desmethyl tirilazad mesylate (U74389) daily via intragastric tube. Liver samples were analyzed for histopathology, nonheme iron, lipid peroxidation and levels of mRNA for tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase-2 (COX-2). Concentrations of endotoxin and 8-isoprostane were measured in plasma. Membrane ATPases were measured in isolated membrane red cells. FE rats developed fatty liver, necrosis and inflammation. Treatment with the 21-aminosteroid resulted in prevention of necroinflammatory changes, but the degree of fatty liver was unchanged. The absence of necroinflammatory changes in the FE-LAZ group was accompanied by a decrease in levels of nonheme iron, lipid peroxidation, TNF-alpha mRNA and COX-2 mRNA. Ethanol administration decreased membrane Ca(++)-ATPase and calmodulin-stimulated Ca(++)-ATPase, and the decrease was reversed by 21-aminosteroid treatment. The data indicate that the improvement in the degree of necrosis and inflammation in the rats treated with the 21-aminosteroid may be explained, at least in part, by reduced levels of proinflammatory stimuli such as lipid peroxidation, TNF-alpha and COX-2. Membrane stabilization may also, by reducing lipid peroxidation, play an additional role in preventing liver injury.
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PMID:The 21-aminosteroid 16-desmethyl tirilazad mesylate prevents necroinflammatory changes in experimental alcoholic liver disease. 943 4

Increased hepatic oxidative stress with ethanol administration is hypothesized to be caused either by enhanced pro-oxidant production or decreased levels of antioxidants or both. We used the intragastric feeding rat model to assess the relationship between hepatic antioxidant enzymes and pathological liver injury in animals fed different dietary fats. Male Wistar rats (5 per group) were fed ethanol with either medium-chain triglycerides (MCTE), palm oil (PE), corn oil (CE), or fish oil (FE). Control animals were fed isocaloric amounts of dextrose instead of ethanol with the same diets. The following were evaluated in each group: liver pathology, lipid peroxidation, manganese superoxide dismutase (MnSOD) levels, copper-zinc SOD (CuZnSOD) levels, glutathione peroxidase (GPX) levels, and catalase (CAT) levels. All enzymes were evaluated using activity assays and immunoblots. Rats fed FE showed the most severe pathology (fatty liver, necrosis, and inflammation), those fed CE showed moderate changes, those fed PE showed fatty liver only, and those fed MCTE were normal. Parameters indicative of lipid peroxidation (conjugated dienes and thiobarbituric acid-reactive substances) were also greater in rat livers from animals fed the diets high in polyunsaturated fatty acids (CE and FE). CuZnSOD, GPX, and CAT activities showed an inverse correlation (r=-.92, P < .01) with severity of pathological injury, with the lowest levels for both enzymes found in FE-fed rats. Decreased enzyme activity in CE- and FE-fed rats was accompanied by similar decreases in immunoreactive protein. Ethanol administration did not cause significant decreases in enzyme activity in groups that showed no necroinflammatory changes (MCTE and PE). MnSOD activity showed no significant change in any ethanol-fed group. Our results show that decreases in CuZnSOD, GPX, and CAT occur in rats showing pathological liver injury and also having the highest levels of lipid peroxidation. These results suggest that feeding dietary substrates that enhance lipid peroxidation can exacerbate both ethanol-induced oxidative damage as well as necroinflammatory changes. The decrease in activity of antioxidant enzymes observed in animals fed diets high in polyunsaturated fatty acids and ethanol could possibly increase the susceptibility to oxidative damage and further contribute to ethanol-induced liver injury.
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PMID:Increased lipid peroxidation and impaired antioxidant enzyme function is associated with pathological liver injury in experimental alcoholic liver disease in rats fed diets high in corn oil and fish oil. 958 86


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