metallothionein and Liver-Cirrhosis--Biliary

Topics: Copper; Hepatocytes; Hepatolenticular Degeneration; Humans; Liver Cirrhosis, Biliary; Metallothionein; Microscopy, Fluorescence

The therapeutic efficacy of ursodeoxycholic acid (UDCA) has been widely demonstrated in various liver diseases, suggesting that UDCA might protect hepatocytes against common mechanisms of liver damage. A candidate for such protection is oxidative injury induced by reactive oxygen species. This study was designed to assess the effects of UDCA on oxidative injury and antioxidative systems in cultured rat hepatocytes. The viability of the hepatocytes dose-dependently decreased after hydrogen peroxide or cadmium administration. Pretreatment with UDCA significantly prevented this decrease in viability. The amounts of glutathione (GSH) and protein thiol increased significantly, but the activities of antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and catalase were unchanged in UDCA-treated hepatocytes. The mRNA levels of gamma-glutamylcysteine synthetase and metallothionein (MT) were significantly higher in UDCA-treated hepatocytes than in controls. In conclusion, UDCA increased hepatocyte levels of GSH and thiol-containing proteins such as MT, thereby protecting hepatocytes against oxidative injury. Our results provide a new perspective on the hepatoprotective effect of UDCA.

Topics: Animals; Antioxidants; Cholangitis, Sclerosing; Glutamate-Cysteine Ligase; Glutathione; Liver; Liver Cirrhosis, Biliary; Male; Metallothionein; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Sulfhydryl Compounds; Ursodeoxycholic Acid

Primary biliary cirrhosis (PBC) patients showed increased ceruloplasmin activity and Cu content in the serum as compared to the control group. Moreover, Cu, Fe, and Zn contents were measured in the livers of autopsied cases. The PBC patients showed increased Cu content and reduced Fe and Zn levels. In PBC cases, Cu transportation via bile is disturbed due to collapse of the interlobular bile ducts and consequently Cu accumulates in the liver. Thus, it is likely that serum ceruloplasmin activity increases to metabolize the accumulated hepatic Cu and that Cu content increases in the serum as a ceruloplasmin-bound form. Furthermore, reduction of Fe and Zn contents in the liver of the PBC patients indicated the possible relationship of ceruloplasmin to Fe and Zn metabolism as well as Cu metabolism.

Topics: Cations; Ceruloplasmin; Copper; Humans; Immunoenzyme Techniques; Iron; Liver; Liver Cirrhosis, Biliary; Metallothionein; Zinc

In patients with primary biliary cirrhosis and Wilson's disease liver copper concentrations become elevated during the evolution of the disorder. The accumulated copper is thought to be detoxified by metallothionein, a protein which binds copper and zinc. In liver metastasis of colorectal cancer, copper and zinc concentrations are usually decreased compared to normal liver tissue, but little is known about the concomitant metallothionein levels. In the present study metallothionein concentrations were determined in archival liver samples from patients with primary biliary cirrhosis and Wilson's disease, and in both normal and malignancy-containing liver samples from patients with metastasis from a colorectal adenocarcinoma. Twenty-seven control liver samples contained 3.98 +/- 1.55 mg metallothionein/g protein. From the 21 liver samples of patients with primary biliary cirrhosis, which had a mean metallothionein concentration of 6.06 +/- 5.03 mg/g protein, 6 were above the highest control level. Liver metallothionein concentrations for the 8 patients with Wilson's disease were significantly elevated (10.98 +/- 6.93 mg/g protein, p < 0.005 vs. controls and p < 0.05 vs. primary biliary cirrhosis). In the 11 liver metastases from colorectal adenocarcinomas metallothionein concentrations (1.17 +/- 0.90 mg/g protein) were significantly (p < 0.005) lower than surrounding normal liver tissue (4.25 +/- 1.75 mg/g protein). We conclude that in primary biliary cirrhosis and Wilson's disease increased liver metallothionein concentrations may detoxify the accumulated copper. Furthermore, liver metastasis of colorectal cancer contains less metallothionein than the surrounding normal liver tissue.

Topics: Adenocarcinoma; Adult; Aged; Colorectal Neoplasms; Female; Hepatolenticular Degeneration; Humans; Liver; Liver Cirrhosis, Biliary; Liver Neoplasms; Male; Metallothionein; Middle Aged; Radioimmunoassay

We studied the Cu-MT present in the hepatic cytosol obtained from 7 patients suffering from conditions associated with hepatic Cu overload (Wilson's disease, biliary atresia, familial cholestatic cirrhosis). Since chromatographic methods appropriate for the isolation of Zn- and Cd-MT were unsuitable for Cu-MT, we developed an indirect procedure for the estimation and resolution of the latter. This procedure involved the preparation of apo-MT and its reconstitution to holo-MT with Zn or Cd. Three predominant isoforms of MT were present in all specimens. Our results indicate that at most 36 +/- 5% of the Cu present in the 10 kDa fraction of cytosol is bound to MT in the liver of patients with hepatic copper overload.

Topics: Adolescent; Adult; Biliary Atresia; Child; Child, Preschool; Copper; Cytosol; Female; Hepatolenticular Degeneration; Humans; Liver; Liver Cirrhosis, Biliary; Male; Metallothionein

The plasma metallothionein concentration was evaluated in healthy subjects and in patients with several types of liver disorders. Plasma metallothionein concentrations in controls varied between 2.4 and 4.8 ng/ml. Patients with disorders associated with increased liver copper concentrations (i.e., primary biliary cirrhosis and primary sclerosing cholangitis) had significantly (both p less than 0.002) elevated plasma metallothionein concentrations (range = 1.8 to 52.2 ng/ml), and a considerable number of these were above the maximum control level (21 of 41 patients). In contrast, patients with liver disorders not associated with increased liver copper concentrations (alcoholic and cryptogenic cirrhosis, and acute viral and chronic active hepatitis) generally had normal plasma metallothionein concentrations and only a few were above the maximum control level (11 of 64 patients, maximum = 8.8 ng/ml). The metallothionein concentrations in plasma samples from patients in stage I or II primary biliary cirrhosis were within or slightly above the control range, whereas most patients in stage III had elevated levels (p less than 0.002), and almost all patients in stage IV had clearly elevated (p less than 0.0001) concentrations. In primary biliary cirrhosis the plasma metallothionein concentration tended to increase during the evolution of the disorder, and the concentration correlated significantly with the serum total bilirubin concentration. In conclusion, the plasma metallothionein concentration is significantly elevated in patients with primary biliary cirrhosis and in patients with primary sclerosing cholangitis. Although related to the histological stage of primary biliary cirrhosis, the measurement of plasma metallothionein concentrations contributes little to the diagnosis or the evaluation of the severity of these disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Humans; Liver Cirrhosis, Biliary; Liver Diseases; Metallothionein; Osmolar Concentration; Radioimmunoassay; Regression Analysis

A copper-containing protein was purified from the liver of a patient with primary biliary cirrhosis by a combination of gel filtration and anion exchange chromatography. This copper-protein had UV absorption and emission spectra, an amino acid composition, and a molecular mass which were characteristic for metallothionein (MT). From 8 livers (3 control, 1 fetal and 4 primary biliary cirrhosis) MT was extracted with non-reducing buffer and centrifuged, and pellets were re-extracted with a 1% 2-mercaptoethanol-containing buffer. The non-reducing buffer extracted a predominantly copper-containing MT from the livers of patients with primary biliary cirrhosis and a predominantly zinc-containing MT from control livers and the fetal liver. Only from the fetal liver was a copper/zinc containing MT solubilized during the re-extraction with 2-mercaptoethanol-containing buffer. These results indicate that human MT is a unique metalloprotein with age and disease-dependent characteristics.

Topics: Amino Acids; Chromatography, Gel; Copper; Humans; Liver; Liver Cirrhosis, Biliary; Metallothionein; Molecular Weight; Zinc

Metallothionein was isolated from the liver of rats pretreated with cadmium. Monospecific anti-metallothionein antibodies were produced in rabbits. Twenty-six primary biliary cirrhosis (PBC) liver samples and three control liver samples were stained for metallothionein by an indirect immunoperoxidase technique. Nineteen of the PBC samples and the control samples were also stained for copper by Timm's silver sulphide method. In all PBC samples the copper concentration was determined. In addition, the zinc, cadmium, and mercury concentrations were measured in some samples. Eighteen of the PBC samples stained for metallothionein showed marked diffuse cytoplasmic and nuclear staining of a varying number of periportal hepatocytes. In none of them was granular staining detected. None of the control samples showed staining. Fourteen of the PBC samples stained for copper showed diffuse cytoplasmic and granular staining of the periportal hepatocytes. In none of them was nuclear staining detected. None of the control samples showed staining. No elevated zinc, cadmium, or mercury concentrations were found but the copper concentration was increased in 21 of the 26 PBC samples. The number of cells staining for copper and metallothionein was assessed semiquantitatively. Significant correlations were found between the grade of metallothionein staining and the liver copper concentration; the grade of Timm's staining and the liver copper concentration; and the grades of metallothionein staining and Timm's staining. The data suggest that the accumulation of copper induces synthesis of cytoplasmic and nuclear metallothionein, and that the increased amount of cytoplasmic copper is bound to a similarly increased amount of metallothionein.

Topics: Adult; Animals; Copper; Cytoplasm; Female; Histocytochemistry; Humans; Immunochemistry; Liver; Liver Cirrhosis, Biliary; Male; Metallothionein; Middle Aged; Rats; Rats, Inbred Strains

Of 1361 consecutive liver biopsy specimens, 24% contained orcein-positive granules. The highest incidence of positivity was found in biliary disease (90.9%), long before cirrhosis had developed, whereas in chronic non-primarily biliary disease, positive results were almost exclusively in patients with well established cirrhosis. Orcein-positive granules were never found in acute liver disease. These granules were also demonstrated in tumour cells of primary hepatocellular tumours (benign 4 of 4 cases; malignant 9 of 37 cases), while all the secondary tumour deposits were negative. In our view the additional information obtained by this technique warrants its adoption as a routine procedure.

Topics: Carcinoma, Hepatocellular; Coloring Agents; Cytoplasmic Granules; Humans; Liver; Liver Cirrhosis, Alcoholic; Liver Cirrhosis, Biliary; Liver Diseases; Liver Neoplasms; Male; Metalloproteins; Metallothionein; Oxazines; Staining and Labeling