Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Weanling male CD-1 mice were fed 120 (control), 5000 and 8000 mg of iron kg-1 for seven weeks. The haematocrit (P = 0.265), water consumption (P = 0.170) and percentage body weight ratios of kidney, spleen and heart were not affected by iron supplementation. 2. Iron supplementation reduced weight gain (P = 0.023), increased weight of liver (P = 0.0001), the iron deposition index and concentration of iron in the liver (P < 0.01). A strong correlation between liver iron concentration and level of iron in the diet (r = 0.989) was observed. Histologically, the deposition of iron was restricted to the hepatocytes, Kupffer cells and splenic macrophages. 3. Consumption of 5000 and 8000 mg of iron kg-1 resulted in hepatic damage, as judged by elevated serum alkaline phosphatase and alanine aminotransferase activities (P < 0.05). 4. This study indicates that prolonged feeding of excess dietary iron has the potential to cause hepatic accumulation of iron with resultant liver toxicity, and that mice may be a suitable model to study the mechanisms of dietary iron overload.
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PMID:Hepatotoxicity associated with dietary iron overload in mice. 790 62

Chronic hepatitis C has been demonstrated to be associated with hepatic iron overload, and the hypothesis that the disease activity of hepatitis C is associated with iron cytotoxicity was tested in male volunteer blood donors. Sera with either antibody to hepatitis C virus or hepatitis B surface antigen were selected for determination of ferritin concentration and alanine aminotransferase activity. A correlation between serum ferritin concentration (Y; microgram/l) and alanine aminotransferase activity (X; IU/l) was found in donors with antibody to hepatitis C (log Y = 0.65 x log X + 0.98, r = 0.53, and P < 0.01). The correlation was lower in donors with hepatitis B surface antigen (r = 0.37; P < 0.01). Hepatitis C virus infection probably induces time-dependent iron accumulation associated with the progression of disease activity, while hepatitis B virus infection results in a variety of iron loads with different clinical features. The high disease activity related to hyperferritinemia suggests the presence of iron-induced liver damage in donors with hepatitis C.
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PMID:Correlation between serum levels of alanine aminotransferase and ferritin in male blood donors with antibody to hepatitis C virus. 800 May 7

An experimental model of secondary hemochromatosis is described. Saccharated iron was administered i.v. to rats for 7 months in total doses in the range 1.0-1.7 g per kg body weight. After the completion of iron loading, the biochemical measurements revealed elevation of alanine aminotransferase (ALT), slight reduction of plasma glucose concentration, and significant reduction of both plasma and liver ascorbic-acid levels. The mean liver iron concentration was 50 times higher in iron-loaded animals than in controls. High concentrations of inorganic iron were also observed in spleen, pancreas, and heart. Histologic analysis revealed marked hepatic fibrosis in most animals in the experimental group. These results demonstrate this animal model presents some pathologic findings observed in human transfusional hemochromatosis. Additionally, hydroxyl free radicals were detected by electron paramagnetic resonance (EPR) spectroscopy in the iron-overloaded liver tissue processed at pH 5.0. No free radicals were detected at pH 7.4. These results suggest the possible participation of hydroxyl free radicals in the cellular toxicity of iron overload.
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PMID:Liver injury and generation of hydroxyl free radicals in experimental secondary hemochromatosis. 838 50

Clinical evidence indicates that patients with iron overload are more susceptible to liver cell damage from alcohol than persons with normal iron stores. Iron may act as a co-factor to catalyze the lipid peroxidation induced by hepatotoxic compounds such as alcohol. To elucidate the role of iron in ethanol-induced hepatocellular damage, we developed a new experimental model in the rat. Following dietary carbonyl iron feeding for 8 weeks, animals were pair-fed a liquid ethanol diet for 4 weeks. In iron-fed animals the liver iron content was 6.4 vs. 0.5 micrograms Fe/mg protein in the controls. Blood alcohol concentrations were similar in all ethanol-fed animals. Serum alanine aminotransferase (ALT) levels were elevated to 269 +/- 49 U/l in the iron+alcohol group compared to 52 +/- 6 U/l in the other groups. There was a strong correlation between ALT levels and hepatic iron content in the ethanol-fed animals. Morphologically, the alcohol-fed rats displayed hepatic steatosis, whereas occasional inflammation and iron in Kupffer cells was seen in the iron+alcohol animals. Ultrastructurally, necrotic hepatocytes and cells phagocytosed by Kupffer cells were only encountered in the iron+alcohol group. Compared to controls, the liver content of hydroxyproline was significantly increased in the iron+alcohol group. No morphological evidence of fibrosis was noted. The present study demonstrates biochemical and morphological evidence of increased hepatocellular damage following the combination of iron and ethanol.
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PMID:Iron increases ethanol toxicity in rat liver. 844 9

We studied 81 patients with chronic hepatitis C to investigate the relationship between iron and alpha-interferon response. Sixty-one patients (group A) were given alpha-interferon irrespective of iron status, whereas 20 (group B) with iron overload, were iron depleted before alpha-interferon therapy. In group A, 21 patients responded to alpha-interferon and 40 were non-responders. Increased iron indices were significantly more frequent in non-responders than responders. Multivariate analysis showed that among the independent variables evaluated, only gamma-GT and liver iron concentration predicted therapy outcome. After phlebotomy treatment, serum alanine aminotransferase fell significantly both in patients of group B (196 +/- 122 IU/l vs 82 +/- 37 IU/l, p < 10(-6)) and in 12 non-responders of group A (198 +/- 89 IU/l vs 107 +/- 81 IU/l, p < 10(-6)). In 16 iron depleted patients, eight from each group, subsequent treatment with alpha-interferon produced a response in only one patient. These results suggest that increased liver iron is a negative prognostic factor for alpha-interferon response in chronic hepatitis C. Iron depletion had a beneficial effect on serum alanine aminotransferase in all the patients treated, but did not improve the response to alpha-interferon.
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PMID:Iron stores, response to alpha-interferon therapy, and effects of iron depletion in chronic hepatitis C. 887 95

The notion that prolonged ethanol consumption promotes hepatocellular damage through interactions with iron was evaluated in rats fed ethanol with or without supplemental dietary carbonyl iron. The individual and combined pro-oxidant potential of these agents was evaluated in terms of their ability to perturb iron homeostasis and initiate hepatocellular injury. Sprague-Dawely rats received a high fat liquid diet for 8 weeks supplemented with: 35% ethanol-derived calories (Alcohol group), 0.02 to 0.04% (w/v) carbonyl iron (Iron group), ethanol plus carbonyl iron (Alcohol + Iron group), or a diet containing carbohydrate-derived isocaloric calories (Control group). Hepatic and serum nonheme iron stores were significantly elevated (p < 0.05) in all treatment groups, compared with the Controls. Catalytically active low-molecular weight iron was detected in rats consuming alcohol and was markedly elevated (p < 0.05) in rats ingesting iron alone or iron in combination with alcohol. Elevations in serum ALT indicated significant hepatocellular injury in rats ingesting only alcohol, but was most prominent in the rats consuming ethanol in combination with iron (p < 0.05). Significant hepatic fatty infiltration, increased hydroxyproline content, and perturbations in reduced glutathione were also observed in the Alcohol and Iron treatment groups. Histochemical assessment of hepatic iron sequestration revealed that alcohol feeding resulted in deposition of ferric iron in the centrilobular area of the liver lobule. This unique alcohol-mediated iron deposition was histologically graded above Control group and was observed in both hepatocytes and Kupffer cells. Data presented herein suggest that alcohol alone or in combination with iron results in rather specific lobular patterns of hepatic iron deposition relevant to iron overload observed in human alcoholics. Furthermore, data suggest that alcohol- and iron-initiated prefibrotic events occur before extensive hepatocellular necrosis.
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PMID:Alcohol mediates increases in hepatic and serum nonheme iron stores in a rat model for alcohol-induced liver injury. 894 10

In thalassemia after successful bone marrow transplantation (BMT), iron overload remains an important cause of morbidity. After BMT, patients have normal erythropoiesis capable of producing a hyperplastic response to phlebotomy so that this procedure can be contemplated as a method of mobilizing iron from overloaded tissues. A phlebotomy program (6 mL/kg blood withdrawal at 14-day intervals) was proposed to 48 patients with prolonged follow-up (range, 2 to 7 years) after BMT. Seven patients were not submitted to the program (five because of refusal and two because of reversible side effects). The remaining 41 patients (mean age, 16 +/- 2.9 years) were treated for a mean period of 35 +/- 18 months. All were evaluated before and after 3 +/- 0.6 years of follow-up. Values are expressed as mean +/- standard deviation (SD) or as median with a range (25 to 75 percentile). Serum ferritin decreased from 2,587 (2,129 to 4,817) to 417 (210 to 982) microg/L (P < .0001), total transferrin increased from 2.34 +/- 0.37 to 2.7 +/- 0.58 g/L (P = .0001), transferrin saturation decreased from 90% +/- 14% to 50% +/- 29% (P < .0001). Liver iron concentration evaluated on liver biopsy specimens decreased from 20.8 (15.5 to 28.1) to 4.2 (1.6 to 14.6) mg/g dry weight (P < .0001). Aspartate transaminase decreased from 2.7 +/- 2 to 1.1 +/- 0.6 (P < .0001) and alanine transaminase from 5.2 +/- 3.4 to 1.7 +/- 1.2 (P < .0001) times the upper level of normality. The Knodell score for liver histological activity decreased from 6.9 +/- 3 to 4.9 +/- 2.8 (P < .0001). These data indicate that phlebotomy is safe, efficient, and widely applicable to ex-thalassemics after BMT.
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PMID:Phlebotomy to reduce iron overload in patients cured of thalassemia by bone marrow transplantation. Italian Cooperative Group for Phlebotomy Treatment of Transplanted Thalassemia Patients. 924 28

No experience has been reported to date in treating chronic hepatitis C virus (HCV) infection with interferon (IFN) therapy after BMT, mainly due to concerns related to the impact of an immunomodulatory drug in patients who are immunologic and haematologic chimeras. However, chronic inflammatory activity related to HCV infection results in a chronic fibrogenous mechanism potentially leading to liver cirrhosis and hepatocellular carcinoma. Moreover, patients transplanted for beta-thalassemia could be at greater risk because of concomitant iron overload and pre-existing fibrous liver damage. Eleven patients with serological, biochemical, histological and molecular biological evidence of HCV infection were included in the study and treated for 6-12 months with recombinant IFN 24-65 months following BMT. The serum alanine aminotransferase (ALT) was persistently elevated (range 85-1242 U/l; mean 416) for at least 1 year prior to IFN treatment. Ten patients completed the protocol; five were considered as responders to treatment. In these five patients the liver histology showed an overall reduction of inflammation and necrosis: histological inflammatory activity improved from chronic active hepatitis (CAH) to chronic persistent hepatitis (three patients) or minimal residual inflammatory activity (two patients). The Knodell total activity score varied from 5.4 (range 3-9) to 1.4 (range 1-2; P = 0.05). All responding patients revealed negativization of serum HCV-RNA, that has been persistent in four (follow-up 1-3 years). ALT level fell to 15-80 U/l (mean 52; P = 0.0027). No major complications occurred during the therapy and no influence on marrow engraftment parameters were noted. We conclude that IFN therapy does not adversely interfere with engraftment and that it is a feasible therapy for treatment of chronic hepatitis C virus after BMT.
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PMID:Alpha-interferon treatment of chronic hepatitis C after bone marrow transplantation for homozygous beta-thalassemia. 938 79

We evaluated therapy complications in 19 beta-thalassemia major patients (mean age from 3 years/5 months and 1 years/6 months) who were followed at II Pediatric Department-University of Bari. 3 out of 19 patients underwent allogenic BMT from matched related donor; 2 out of 19 underwent splenectomy. All of them were receiving hypertransfusion therapy and continuous chelation with DFO. In all patients we performed physical examination, laboratory assays, cardiac and endocrinologic function tests, serum HBV-HCV-HIV antibodies, otoscopy and audiometric test, fundus oculi, skeletal x-ray. 1 out of 19 patients, who was under 15, had a slight dilatation of left ventricle and arythmia. All patients were HBsAb positive. 4/19 patients were HCV Ab positive (ELISA test) with an increase in ALT-AST serum levels since at least 6 months. In 3 of them we assessed RIBA test, always positive. 3 of them underwent liver biopsy (1 iron overload 2 chronic active hepatitis). All patients were HIV Ab negative. 4/15 patients revealed low GH levels after Arginina test. 13 pre-pubescent patients had normal results with GNRH test but lower results after FSH test. 1 pubescent patient had gonadotropic hypophyseal deficit. 4 patients had subclinic hypothiroidism. We couldn't find any sequelas in bone-eyes-ears. Hypertransfusion therapy, chelation, profilaxis of infections improved length and quality of life in thalassemic patients. Hypogonadotropic hypogonadism remains a serious sequela and we think it needs to be treated.
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PMID:[Long-term effects of combined therapy in patients with beta-thalassemia major]. 965 19

The alpha-class glutathione S-transferases are proposed to play a prominent role in catalyzing the conjugation of glutathione with electrophilic aldehydic products of lipid peroxidation. The effect of iron-induced lipid peroxidation on induction of glutathione S-transferase (GST) isozymes A1 and A4 in the livers of male C57/BL6Ibg and DBA/J2Ibg mice was studied. C57 and DBA mice were fed for 4 months on a diet supplemented with iron as ferrocene and then were assessed for liver injury, hepatic iron loading, indices of lipid peroxidation, GST activity, and induction of GST isozymes A1 and A4. Iron-treated animals displayed a loss in body weight from pair-fed controls and had large increases in hepatic non-heme iron with concomitant liver injury, as measured by serum alanine aminotransferase. Hepatic lipid hydroperoxides, a direct measure of oxidized membrane lipids, were significantly increased only in C57 mice, but hepatic concentrations of reduced glutathione (GSH) were significantly increased in both inbred strains. Total GST activity toward 1-chloro-2,4-dinitrobenzene was significantly increased in C57 mice but not in DBA. Western blot studies using polyclonal antibodies specific for GST A1 and A4 revealed significant increases of 1.5-2.0-fold in these GST isoforms in both inbred strains. These results in a unique murine model for hepatic iron overload further support recent in vivo studies (Khan et al., Toxicol. Appl. Pharmacol., 131, 63-72, 1995) that have associated induction of GST A4 with protection against oxidative stress-induced lipid peroxidation. The observed increases in lipid hydroperoxides, hepatic GSH, GST activity, and GST A1 and A4 protein strongly support the hypothesis that induction of GST A1 and A4 represents an important protective event in the detoxification of electrophilic products of lipid peroxidation.
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PMID:Association of glutathione S-transferase isozyme-specific induction and lipid peroxidation in two inbred strains of mice subjected to chronic dietary iron overload. 970 1


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