Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.3.1.109 (AST)
6,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To test further the competence of the cirrhotic liver to metabolize vitamin D3 at C-25, hepatocytes were isolated from controls and from CCl4-induced cirrhotic rat livers, as well as from partially hepatectomized rats. The transformation of D3 into 25-hydroxyvitamin D3 was studied in the presence of 10(7) hepatocytes at D3 concentrations of 20 nmol/L to 15.4 mumol/L. Histologically, micronodular cirrhosis was present in all CCl4-treated rats, whereas controls had normal livers; portal venous pressure (p less than 0.008) and intrahepatic collagen content (p less than 0.0001) were significantly increased in CCl4-treated rats, whereas no difference was found between the two groups in the total and ionized serum calcium, D3 metabolites, ALT, AST and alkaline phosphatase. Cytochrome P-450 was 0.27 +/- 0.02 and 0.25 +/- 0.02 nmol/10(6) hepatocytes in controls and cirrhotic rats (N.S.), and it significantly increased in both groups after phenobarbital or 3-methylcholanthrene administration (p less than 0.0001). 25-Hydroxyvitamin D3 formation was best described by power law equations and varied between 0.02 +/- 0.0004 and 29.57 +/- 2.8 in controls, and 0.024 +/- 0.0004 and 32.0 +/- 7.0 pmol.hr-1.10(6) hepatocytes-1 in cirrhotic rats. No statistically significant difference was found in the slopes of the 25-hydroxyvitamin D3 formation, but the y-axis intercept was found to be lower in cirrhotic rats under basal resting conditions (p less than 0.005). Inducers of the mixed function oxidases significantly increased 25-hydroxyvitamin D3 formation in controls as well as in cirrhotic rats (p less than 0.005). Moreover, both groups were found to respond similarly to the addition of modulators of the enzyme such as the calcium ionophore A23187 and parathyroid hormone. Partial hepatectomy was also without effect on the activation of D3. Furthermore, the cell sequestration of D3 was also found to be unperturbed in hepatocytes obtained from either cirrhotic or partially hepatectomized livers. The data indicate that in well-compensated micronodular cirrhosis, the C-25 hydroxylation of D3 is generally intrinsically normal at the cellular level and that it also remains fully responsive to in vivo and in vitro modulators of its activity.
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PMID:In micronodular cirrhosis, hepatocytes retain a normal C-25 hydroxylation capacity toward vitamin D3: a study using the rat carbon tetrachloride-induced cirrhotic model. 184 94

A study was conducted to examine the inhibitory effect of acyclic retinoid (polyprenoic acid) on the development of hepatic fibrosis induced by CCl4 in rats. Oral administration of the compound brought about a significant reduction in both serum and tissue levels of immunoreactive prolyl hydroxylase, a key enzyme of collagen formation. The result indicated that the rate of collagen synthesis in the liver was decreased which was consistent with histological findings. Acyclic retinoid also decreased both AST and ALT activities in serum, demonstrating the reduction in hepatic parenchymal damage. This cytoprotective effect on parenchymal cells may be related, at least in part, to inhibition of hepatic fibrosis. No significant side effects were observed, despite a long-term administration of the acyclic retinoid. The present findings suggest the potential scope of therapy of hepatic fibrosis by retinoid.
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PMID:Inhibitory effect of acyclic retinoid (polyprenoic acid) on hepatic fibrosis in CCl4-treated rats. 216 74

Alcoholic and, to a lesser extent, nonalcoholic patients with liver disease have serum antibodies to acetaldehyde-protein adducts produced in vitro. These antibodies presumably reflect the presence of adducts in the liver, but the protein that triggers this immune response has not been identified. To study this, we measured the reactivity of cytosolic proteins to rabbit IgG developed against a P-450 2E1-acetaldehyde adduct, isolated from alcohol-fed rats, that recognizes acetaldehyde-modified epitopes in proteins. Adducts were determined on Western blots by scanning densitometry of antibody-linked alkaline phosphatase activity in 4 normal livers and in needle biopsy specimens from subjects with liver disease, 17 alcoholic and 14 nonalcoholic. In all livers, except for a normal one, we found a reactive protein of at least 200 kD, similar to the collagen-acetaldehyde adduct we reported to be markedly increased in rats with experimentally induced cirrhosis. The immunostaining intensity in the alcoholic patients with liver disease was eightfold (p < 0.01) and that in nonalcoholic patients with liver disease was fourfold, greater (p < 0.02) than the weak staining in normal livers; it correlated with the degree of inflammation and serum AST or gamma-glutamyl transpeptidase activities. The adduct was reproduced on incubation of normal cytosolic proteins with 2.5 mmol/L acetaldehyde, whereas higher concentrations yielded many additional adducts; the adduct also reacted with IgG antibody to rat collagen type I and disappeared after digestion with collagenase, suggesting that the target protein is a form of collagen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Collagen-acetaldehyde adducts in alcoholic and nonalcoholic liver diseases. 791 86

We examined 95 ground squirrels to compare the histological appearance of liver sections from animals that were chronically infected with ground squirrel hepatitis virus (GSHV) (n = 29), uninfected (n = 42), or had recovered from infection (n = 24). We studied the effects of long-term infection because these animals had been infected with GSHV for up to 10 years. Chronic infection generally produced a mild, persistent hepatitis characterized by light lymphocytic and plasmacytic portal infiltrates with occasional individual necrotic hepatocytes and small aggregates of Kupffer cells or mononuclear inflammatory cells in the parenchyma. In a few of the portal tracts from each of the more inflamed livers (grade 2), the inflammatory infiltrate penetrated the limiting plate and extended into the adjacent parenchyma. Hepatitis (grades 1 or 2) was detected more often in chronically infected animals (17 of 29) than in recovered (4 of 24) or uninfected ground squirrels (7 of 42). Fibrosis was generally not increased, but fine strands of collagen extended from the portal tracts and central veins into the parenchyma of about one quarter of the infected and recovered animals. Cytoplasmic pigment accumulation and variation in the size of hepatocyte nuclei appeared to be related to aging, not infection. Serum levels of aspartate and alanine transaminases (AST and ALT) were mildly elevated in samples from seven infected animals compared with seven control animals. Despite many years of chronic infection, liver injury was similar to that reported in previous studies on animals infected for shorter intervals, indicating that liver injury is not progressive in GSHV-infected ground squirrels.
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PMID:Non-neoplastic liver disease associated with chronic ground squirrel hepatitis virus infection. 867 46

Liver fibrosis was induced by chronically (7 weeks) administering CCl4 to rats. Animals were divided into four groups: (a) controls, (b) treated with CCl4 alone, (c) treated with CCl4 and colchicine and (d) treated with CCl4 and formyl-colchicine bound to lactosaminated serum albumin (FC-LASA). Liver dysfunction was monitored by biochemical tests (alkaline phosphatase [ALP], gamma-glutamyltransferase [gamma GT], aspartate and alanine transaminases [AST and ALT], albumin and total bilirubin). Fibrosis was evaluated by determining hydroxyproline and by microscopic examination. The exposure to CCl4 produced major alterations of liver structure and collagen deposition. These effects were partially counteracted by colchicine and to a greater extent by FC-LASA. Morphological findings paralleled biochemical data. The information reported here indicates that colchicine has an antifibrotic activity on the liver of intoxicated rats and that FC-LASA is more active than colchicine itself as an antifibrotic agent.
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PMID:Formylcolchicine bound to lactosaminated serum albumin is a more active antifibrotic agent than free colchicine. 889 3

Chronic liver disease is often accompanied by hypoxaemia. We investigated the clinical factors that were related to the arterial oxygen tension (PaO2) in 40 women, all non-smokers with chronic liver disease. They were positive for hepatitis C virus (HCV) antibody and had no evidence of cardiopulmonary disease. Arterial blood was collected from patients at rest (> 15 min) for analysis of blood gases. We determined the correlation between blood gas tension and the clinical variables, i.e. the presence or absence of skin manifestations such as cutaneous spider nevi and palmar erythema, the presence or absence of splenomegaly, vital capacity, forced expiratory volume in one second, V25/body height, serum alanine aminotransferase (AST), serum asparate aminotransferase (ALT), serum cholinesterase, serum gamma-globulin/total protein, excretion of indocyanine green at 15 min (15-min retention rate, ICG level), blood level of ammonia, blood level of endotoxin, plasma level of glucagon and the serum level of type IV collagen-7S. The mean level of PaO2 was 78 +/- 11 (range: 43-95) torr. The mean alveolar-arterial oxygen tension gradient (A-aDO2) was 19 +/- 13 (range: 2-60) torr. Multiple regression analysis used PaO2 and A-aDO2 as objective variables, and the clinical findings as explanatory variables. The explanatory variables that were significantly correlated with blood gas values were ICG level, blood level of endotoxin and presence of skin manifestations. The ICG level showed a high correlation with blood gas values; the ICG level increased, the PaO2 decreased (r = -0.69), while the A-aDO2 showed a high positive correlation (r = +0.78, P < 0.001). Findings suggest that a reduction in hepatic blood flow and hepatocellular function interfere with the inactivation of vasoactive substances such as endotoxin by the liver, leading to the development of skin manifestations, the dilatation of intrapulmonary capillaries and the induction of hypoxaemia.
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PMID:Clinical factors that affect blood gases in non-smoking women with chronic liver disease. 951 26

Colchicine in a dose of 200 micrograms kg body weight/day (5 days/week) was administered to groups of Schistosoma mansoni infected mice 12 weeks post infection, either alone or following previous praziquantel therapy at the 8th week of infection. Certain groups received colchicine for 6 weeks and others received it for 10 weeks. Colchicine alone did not significantly change the light microscopic appearance of schistosomal liver fibrosis, or hepatic collagen content estimated histomorphometrically, and did not reduce the elevated IL-2 serum level. Colchicine induced hepatic injury consisted of intense inflammatory reaction in granuloma and portal tracts, hepatocytic degeneration, and elevation of serum AST and ALT levels. Colchicine seemed to postpone granulomatous reaction healing and collagen deposition rather than inhibiting collagen formation or degrading it. Colchicine inhibited proliferation of hepatocytes of infected mice by expanding G2-M phases of cell cycle, thus reduced Ag NOR count and raised cell ploidy and cyclic AMP serum level. Subsidence of schistosomal infection by praziquantel prior to colchicine therapy greatly reduced inflammatory cellular reaction, significantly diminished hepatic collagen deposition and serum IL-2 level, minimized the elevated nuclear ploidy and cyclic AMP serum level that followed colchicine therapy when administered alone.
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PMID:Colchicine therapy for hepatic murine schistosomal fibrosis: image analysis and serological study. 1036 84

Circulating uremic substances are thought to be involved in the progression of chronic renal failure (CRF). An oral adsorbent AST-120 (Kremezin) is effective in removing circulating uremic toxins from the gastrointestinal tract, and retards the progression of CRF. AST-120 is widely used as an approved drug in Japan for the treatment of undialyzed uremic patients to delay the progression of CRF. AST-120 attenuates the progression of glomerular sclerosis and interstitial fibrosis in a variety of experimental rat models of CRF. However, the mechanism by which AST-120 delays the progression of CRF had not been clear. We have demonstrated that indoxyl sulfate, a dietary protein metabolite, is a circulating uremic toxin stimulating glomerular sclerosis and interstitial fibrosis, and that AST-120 decreases the serum and urine levels of indoxyl sulfate by adsorbing its precursor, indole, in the intestine. The administration of indoxyl sulfate to uremic rats stimulated the expression of transforming growth factor (TGF)-beta1, tissue inhibitor of metalloproteinase (TIMP)-1 and pro-alpha1(I)collagen in the kidneys. Further, the administration of AST-120 to uremic rats reduced the extent of glomerular sclerosis and interstitial fibrosis as well as the renal expression of TGF-beta1 and TIMP-1, by reducing the serum and urine levels of indoxyl sulfate. We propose the protein metabolite hypothesis that endogenous protein metabolites such as indoxyl sulfate play an important role in the progression of CRF, and that AST-120 is effective in retarding the progression of CRF by removing these protein metabolites through intestinal absorption.
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PMID:Preventive effects of an oral sorbent on nephropathy in rats. 1068 68

Traditional Chinese medicine is still being extensively used for treatment of liver disease in China. The anti-viral herbs, Phyllanthus amarus, P. niruri and P urninaria, and Oxymatrine extracted from Sophora flavecientis and S. subprostratae, have been shown to have a remarkable HBV suppressing effect with a serum conversion rate for HBeAg and HBV DNA around 45%, similar to that of IFN-alpha. The anti-inflammatory compound, Stronger NeoMinophagen C (SNMC), is a Japanese preparation of glycerrhizin, extracted from Glyceriza glabra, which has shown an effective rate of ALT and AST normalization and reduction to < 60 U/L in 65.6%, and 73.5% of patients. Compound 861, made of 10 herbs with Salvia miltiorrhiza as its chief component, has been shown experimentally to be effective in suppressing fibrogenesis, enhancing collagen degradation, and inhibiting TIMP expression. Clinically, an open trial of 2,000 patients showed improvement of symptoms in 83% and normalization of serum ALT in 82%. In a controlled study of 107 patients with HBV-related diseases, double liver biopsies showed that the fibrosis reversal rate after 6 months treatment with Cpd 861 was 78% in S2, 82% in S3 (precirrhotic stage) and 75% in S4 (early cirrhosis), as assessed by Scheuer's and Chevallier's criterion. In conclusion, traditional Chinese medicine has great potential in the treatment of chronic hepatitis B.
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PMID:Treatment of chronic liver diseases with traditional Chinese medicine. 1092 85

Over 90% of intravenous heroin addicts (IVHAs) carry the hepatitis C virus (HCV). The other hepatitis viruses, A, B, D, and G are relatively unimportant in IVHAs compared to HCV although active hepatitis B may demonstrate a chronic, degenerative course identical to that of HCV. The clinical course of HCV and active hepatitis B may span three or more decades. It is helpful to classify patients as in the active, cirrhosis, or liver failure stages. Only in the active, early stage are the liver enzymes, ALT and AST, likely to be elevated. It is this stage that will most likely respond to antiviral therapy. HCV has so many extra-hepatic manifestations including immune suppression, collagen diseases, and possibly lymphoma and leukemia that the disease is best termed HCV syndrome rather than simple hepatitis.
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PMID:Hepatitis C, B, D, and A: contrasting features and liver function abnormalities in heroin addicts. 1128 27


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