Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Copper (Cu) accumulating bound to metallothionein (MT) in the liver of LEC (Long-Evans with cinnamon-like coat color) rats due to a hereditary metabolic disorder is assumed to lead to acute hepatitis with severe jaundice. The metal was shown to be present in the liver in a form not bound to MT at the beginning of hepatitis after first delivery and lactation. Following this change in the distribution of Cu from MT-bound to non-MT bound form in the liver, changes in the concentrations and distributions of Cu, zinc (Zn) and iron in the plasma and kidneys of LEC rats were also observed. Cu plasma distribution on a gel filtration column by HPLC-ICP revealed that the holo-form of ceruloplasmin (Cp) was present before hepatitis and increased with its development, indicating the availability of Cu for Cp by hepatitis. Cu-binding proteins migrating at the same retention times as those of hepatic Cu-MT and Cu,Zn-superoxide dismutase (SOD) were detected in plasma during hepatitis. Albumin was largely present in the form of nonmercaptoalbumin, reflecting that the bloodstream was under oxidative stress. A sudden increase in the concentration of Cu in the kidneys occurred with hepatitis, and the metal came to be distributed more to high molecular weight proteins with its development.
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PMID:Changes in copper distribution in the plasma and kidneys of LEC rats following acute hepatitis. 830 90

Long-Evans Cinnamon (LEC) rats, a mutant strain originating from Long-Evans rats, spontaneously develop hereditary hepatitis followed by hepatocellular carcinoma. The hepatic disorder in LEC rats is associated with their abnormal copper metabolism; metal-catalyzed reactions often give rise to oxygen radicals, which may be related to the carcinogenesis. By means of high-pressure liquid chromatography with electrochemical detection, cellular DNA damage caused by oxygen radicals can be assessed in terms of the amount of 8-hydroxydeoxyguanosine (oh8dG). We assayed the amount of oh8dG in DNA of liver, kidneys, and brain of LEC and Long-Evans Agouti (LEA) control rats in seven groups (n = 3 to 6) aged from 5 weeks to 24 months. Control rats, a healthy sibling line, were age-matched. The amount of oh8dG was correlated with the severity of the age-related clinical symptoms in LEC rats. The amount was higher in LEC rats than in the controls, especially in the liver at the acute stage of hepatitis. These findings suggest that oxygen radicals may be important in the carcinogenesis that occurs in LEC rats.
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PMID:Elevated level of 8-hydroxydeoxyguanosine in DNA of liver, kidneys, and brain of Long-Evans Cinnamon rats. 832 Jan 67

Distribution of metallothionein (MT) and copper ion (Cu) in the liver of LEC (Long-Evans Cinnamon) rats was investigated to examine the relationship between Cu-MT induction and the development of hepatitis followed by hepatocellular carcinomas. Immunohistochemical studies on MT in the liver of LEC rats indicated that MT is accumulated in nuclei and cytosols. Both MT and Cu, estimated by radioimmunoassay and flameless atomic absorption spectrometry, respectively, in subcellular fractions of the liver were found to be concentrated highest in cytosols, followed by nuclei, mitochondria and microsomal fractions. Gel-filtration (Sephadex G-75) studies demonstrated that MT is induced as the Cu-MT form. Furthermore, the Cu-MT fragment purified by the gel-filtration contains the Cu(I)-MT form, as demonstrated by ESR (electron spin resonance) measurements at 77K. These results will be important for understanding the development of hepatitis in LEC rats.
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PMID:Copper-metallothionein distribution in the liver of Long-Evans cinnamon rats: studies on immunohistochemical staining, metal determination, gel filtration and electron spin resonance spectroscopy. 838 94

The LEC (Long-Evans cinnamon) rat is a mutant strain displaying hereditary hepatitis and spontaneous hepatocellular carcinoma, and shows abnormal hepatic copper accumulation similar to that occurring in Wilson's disease. We evaluated the iron metabolism of LEC rats compared to LEA (Long-Evans agouti) rats. Hepatic iron and ferritin concentrations were remarkably increased depending on age in LEC rats but not in LEA rats. Increased hepatic iron is normally associated with decreased serum transferrin and total iron binding capacity in hepatic iron overload. In LEC rats, however, both serum transferrin and total iron binding capacity increased with increasing hepatic iron. This increase of serum transferrin and hepatic iron may be an additional important factor contributing to liver injury in LEC rats.
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PMID:Abnormal hepatic iron accumulation in LEC rats. 838 76

We carried out the following three experiments to clarify the mechanism of hepatocarcinogenesis in Long-Evans Cinnamon (LEC) rats. (1) Sensitivity to diethylnitrosamine (DEN): LEC rats (8 and 25 weeks old) without and with hepatitis and age-matched F344 rats were administered an intraperitoneal injection of a low dose of DEN. Eight weeks after the injection, the numbers of glutathione-S-transferase placental-form (GST-P)-positive foci in the 33-week-old LEC rat liver were significantly higher than those in the livers of the other three groups of rats. (2) Potential for unscheduled DNA synthesis (UDS): Isolated hepatocytes of 25-week-old LEC rats with chronic hepatitis showed about one-third the level of UDS induced by UV irradiation, as compared to that of age-matched F344 rats, while no significant difference was found between the UDS of isolated hepatocytes of 8-week-old LEC rats and age-matched F344 rats. (3) Potential for proliferation: Isolated hepatocytes from 8-week-old LEC rats responded well to epidermal growth factor (EGF) in culture, to almost the same degree as F344 rat hepatocytes, while a remarkable decrease in the responsiveness of hepatocytes isolated from 25-week-old LEC rats to EGF was found. These results suggested that LEC rat hepatocellular carcinoma could be naturally initiated after the onset of hepatitis by carcinogens contaminating food and the environment, probably due to the reduction of DNA repair activity, after which initiated hepatocytes selectively proliferate in response to growth stimuli endogenously produced as a result of continuous loss of hepatocytes (chronic hepatitis), because of a decrease in growth activity of non-initiated hepatocytes.
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PMID:High sensitivity of LEC rats with chronic hepatitis to hepatocarcinogenesis: decreases in unscheduled and replicative DNA synthesis of the hepatocytes. 840 64

The expression of 14 forms of cytochrome P450 in the liver as well as changes in the testosterone hydroxylation activities of hepatic microsomes were investigated during the development of hepatitis in Long-Evans Cinnamon (LEC) rats. P4501A1 and -1A2 (3-methylcholanthrene-inducible forms) and P4502B1 and -2B2 (phenobarbital-inducible forms) were barely detected in the hepatic microsomes of male and female LEC rats. In immature male rats, the levels of male-specific forms (P4502C11 and -2C13) were higher in LEC rats than in control Long-Evans Agouti (LEA) rats. P4502C11 appeared in female LEC rats from 4 to 16 weeks of age, reflecting that testosterone 2 alpha- and 16 alpha-hydroxylation activities were detected at significant levels in female LEC rats. In immature female rats, the level of P4502C12 (a major female-specific form) was higher in LEC rats than in LEA rats. The level of P4502C13 in male LEC rats and that of P4502C12 in female LEC rats decreased markedly with ageing or during the development of hepatitis. The level of P4503A2 (a male-predominant form) was especially high in immature male and female LEC rats, reflecting that both rats had high 2 beta- and 6 beta-hydroxylation activities toward testosterone. These sex-specific forms are regulated by androgens and by pituitary growth hormone. Thus, there may be abnormalities of the hypothalamo-pituitary-gonadal axis in LEC rats. Furthermore, P4503A2 efficiently activates aflatoxin B1, a potent hepatocarcinogen, and the increased levels of this form in LEC rats may be related to the onset of hepatitis or liver cancer.
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PMID:Expression of cytochrome P450 in LEC rats during the development of hereditary hepatitis and hepatoma. 842 59

Long-Evans Cinnamon (LEC) rats are autosomal recessive mutants that develop hepatitis and hepatocellular carcinoma. Because copper accumulates in the livers of these rats, and some of their clinical and pathological features are similar to those of patients with Wilson's disease, LEC rats are proposed as an animal model of Wilson's disease. It has been thought that unbound copper generates free radicals, which act as hemolytic and hepatocytotoxic agents. To examine the effects of vitamin E as an antioxidant on hereditary hepatitis in LEC rats, we fed 3-week-old rats for 25 weeks either vitamin E-deficient, control, or vitamin E-supplemented diets which contained < 0.01 mg of total tocopherols, 2 mg of d,l-alpha-tocopheryl acetate (2 I.U.), and 58.5 mg of d,l-alpha-tocopheryl nicotinate (50 I.U.), respectively, per 100 mg of feed. In males, body weight loss was first observed in the vitamin E-deficient group, and mean ages at which jaundice occurred were in the order: deficient younger than control younger than supplemented groups. The ages when plasma glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities began to increase sharply and peaked followed the same order. Thus, it is likely that free radicals are involved in jaundice and hepatitis in LEC male rats, and they are a model for studying the relationship of copper, free radicals, and hepatitis. Conversely, in females, no apparent differences in clinical and biochemical changes were observed among the three groups. Causes for the discrepancy between the sexes remain to be clarified.
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PMID:Effects of dietary vitamin E on clinical course and plasma glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities in hereditary hepatitis of LEC rats. 845 79

The Long-Evans with a cinnamon-like color (LEC) rat is a mutant of the Long-Evans strain that develops hereditary hepatitis and hepatoma with ageing. Age-related changes in the mRNA expression of DNA methyltransferase (DNA MTase) were examined in livers of LEC rats using Long Evans with an agouti color (LEA) rats as controls. A dramatic increase in the expression of this mRNA was observed in LEC rats at 20 weeks when acute hepatitis appeared. Their high mRNA levels were maintained until 52 weeks of age. The mRNA expression as well as DNA MTase activities were found to be higher in cancer lesions than in adjacent normal tissue. These increases may be related to liver regeneration and to early events in cellular transformation of LEC rats.
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PMID:Expression of DNA methyltransferase in LEC rats during hepatocarcinogenesis. 847 22

The Long Evans Cinnamon (LEC) rat spontaneously develops fulminant hepatitis, which is usually lethal due to excess copper accumulation in the liver and is considered an animal model of Wilson's disease. LEC rats show a strong appetite for proline solution. Daily oral (p.o.) administration of proline resulted in significant delay of mortality. Feeding a copper-deficient diet greatly delayed the onset of jaundice and mortality and voluntary consumption or p.o. administration of proline further delayed jaundice and prevented mortality. LEC rats also consume ascorbic acid solutions, and p.o. administration of ascorbate also results in a significant delay in the appearance of jaundice and mortality. Combined treatment with ascorbic acid and proline is additive to delay further jaundice and mortality. An endogenous antioxidant protein, thioredoxin, when infused by minipump IP, could also inhibit the incidence of jaundice. These results indicate that antioxidant treatment combined with proline may be of benefit in Wilson's disease and possibly other forms of hepatic dysfunction.
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PMID:Proline, ascorbic acid, or thioredoxin affect jaundice and mortality in Long Evans cinnamon rats. 854 67

We report changes in free radical-metabolizing enzymes and the increased generation of lipid peroxides associated with extreme metal accumulation in the liver of the Long-Evans with cinnamon-like coat color (LEC) rat, a new mutant strain displaying hereditary hepatitis and subsequent hepatocellular carcinoma. The activity of free radical-metabolizing enzymes and lipid peroxides, and the concentration of metal in the liver were determined sequentially after birth. Mn-superoxide dismutase activity significantly increased immediately after the onset of hepatitis in LEC rats, whereas no remarkable change was observed in control rats. Cu, Zn-superoxide dismutase activity in LEC rats was similar to that in control rats. Glutathione reductase activity increased, while glutathione peroxidase activity was lower in LEC rats than in control rats throughout the observation periods. Lipid peroxides, estimated by thiobarbituric acid reaction, also increased 4- to 5-fold immediately after the onset of hepatitis in LEC rats. Copper concentration was 30- to 50-fold higher in the liver of LEC rats than in control rats, and the iron content also increased significantly before and after the onset of hepatitis. These findings suggested that an oxidant injury generated by toxic metals could be one of the factors responsible for hepatocellular damage in this unique hereditary hepatitis.
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PMID:Changes in free radical-metabolizing enzymes and lipid peroxides in the liver of Long-Evans with cinnamon-like coat color rats. 857 34


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