Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Defects of the respiratory chain are a typical feature of mitochondrial diseases and occur also during normal aging where they have been described in postmitotic tissues. The present study addresses the question of defect expression in the normal and cirrhotic liver. Randomly distributed defects of complex III (ubiquinone-cytochrome-c-oxidoreductase) and of complex IV (cytochrome-c-oxidase) of the respiratory chain have been detected with age-related increasing frequency both in normal and cirrhotic livers. No defects were present for complex II (succinate-dehydrogenase) and complex V (adenosine triphosphate-synthase) and in liver cell carcinomas. Sixty-one of 107 normal livers (57%) showed defects of the respiratory chain. The defects occurred in advanced age (over 50 years) in 87%. In contrast 50 of 64 cirrhotic livers (78%) had defects and approximately 60% occurred after age 50. The defects were caused by a loss of enzyme protein involving both nuclearly and mitochondrially coded subunits. Ninety-four percent of the defects (n = 275) involved complex IV selectively. In 4% selective defects of complex III were found and combined defects of both complexes occurred in only 2%. In situ hybridization and polymerase chain reaction (PCR) studies for the detection of the common deletion (4.977 bp) and of various point mutations of mitochondrial DNA (mtDNA) revealed no consistent molecular genetic abnormalities in microdissected respiratory chain defective liver cell areas. Single point mutations at nt 3243 and/or 5692 were found only in 7 of 18 microdissected probes from 6 patients. The results show that defects of the respiratory chain occur already in normal livers most probably during cell aging and at a higher rate in cirrhosis. The random defect pattern favors a stochastic process, e.g., free radical damage. However, the role of mutations of mtDNA remains to be established.
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PMID:Defects of the respiratory chain in the normal human liver and in cirrhosis during aging. 930 2

Wilson's disease is an inherited disorder of copper metabolism characterized by hepatic cirrhosis and neuronal degeneration. In this current study, a polyclonal antiserum specific for the Wilson's disease ATPase was used to examine the hepatic expression of this protein. Immunoblot analysis of lysates from human and rat liver detected a single 165-kDa protein, which by immunofluorescence was present only in hepatocytes and localized predominantly to the trans-Golgi network and exclusively in this compartment under low hepatic copper concentrations. Although hepatic copper concentration had no effect on the steady-state levels of the Wilson's disease protein, copper administration in vivo resulted in redistribution of this protein to a cytoplasmic vesicular compartment localized toward the hepatocyte canalicular membrane. The relative abundance of the Wilson's disease protein in the liver was found to be greatest in the fetus before the onset of biliary copper excretion. Taken together, these studies reveal a novel posttranslational mechanism of copper homeostasis in vivo consistent with the proposed function of the Wilson's disease protein in holoceruloplasmin biosynthesis and biliary copper excretion and of relevance to the broad clinical heterogeneity observed in this disease.
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PMID:Hepatocyte-specific localization and copper-dependent trafficking of the Wilson's disease protein in the liver. 1007 40

The Atp7b protein is a copper-transporting ATPase expressed predominantly in the liver and to a lesser extent in most other tissues. Mutations in the ATP7B gene lead to Wilson disease, a copper toxicity disorder characterized by dramatic build-up of intracellular hepatic copper with subsequent hepatic and neuro-logical abnormalities. Using homologous recombination to disrupt the normal translation of ATP7B, we have generated a strain of mice that are homozygous mutants (null) for the Wilson disease gene. The ATP7B null mice display a gradual accumulation of hepatic copper that increases to a level 60-fold greater than normal by 5 months of age. An increase in copper concentration was also observed in the kidney, brain, placenta and lactating mammary glands of homo-zygous mutants, although milk from the mutant glands was copper deficient. Morphological abnormalities resembling cirrhosis developed in the majority of the livers from homozygous mutants older than 7 months of age. Progeny of the homozygous mutant females demonstrated neurological abnormalities and growth retardation characteristic of copper deficiency. Copper concentration in the livers of the newborn homozygous null mutants was decreased dramatically. In summary, inactivation of the murine ATP7B gene produces a form of cirrhotic liver disease that resembles Wilson disease in humans and the 'toxic milk' phenotype in the mouse.
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PMID:Null mutation of the murine ATP7B (Wilson disease) gene results in intracellular copper accumulation and late-onset hepatic nodular transformation. 1044 29

Semiquantitative immunoblotting was used to investigate the expression levels of the four major renal aquaporins, the Na-K-2Cl cotransporter of the thick ascending limb, the type 3 Na-H exchanger, and the Na-K-ATPase in kidneys from rats with cirrhosis secondary to common bile duct ligation (CBDL). These rats had significant water retention and hyponatremia. In contrast to models of cirrhosis induced by carbon tetrachloride, aquaporin-2 expression in CBDL-induced cirrhosis was decreased. Thus, these results show that in the setting of extracellular fluid volume expansion, excessive water retention with hyponatremia can occur in the absence of increases in aquaporin-2 abundance. In addition, the expression levels of the two basolateral collecting duct aquaporins (aquaporin-3 and -4) were decreased in CBDL rats relative to sham-operated control rats. Similarly, the Na-K-2Cl cotransporter of the thick ascending limb and the type 3 Na-H exchanger showed decreases in expression. In contrast, the expression levels of aquaporin-1 and the all subunit of the Na-K-ATPase were not decreased. Thus, dysregulation of multiple water channels and ion transporters may play a role in water balance abnormalities associated with CBDL-induced cirrhosis in rats.
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PMID:Renal expression of aquaporins in liver cirrhosis induced by chronic common bile duct ligation in rats. 1047 47

Rabeprazole, a newly developed proton pump inhibitor, has been shown to be effective for the treatment of gastric and duodenal ulcers and for gastro-oesophageal reflux disease. It is a rapid and potent inhibitor of gastric H+,K(+)-ATPase, the gastric acid (proton) pump. The maximum plasma concentration (Cmax) and the area under the plasma concentration time curve (AUC) are linearly related to dose, while the time to maximum plasma concentration (tmax) and elimination half-life (t1/2) are dose-independent. Rabeprazole is extensively metabolized in the liver via the cytochrome P450 enzyme system, and its metabolites are excreted primarily in the urine. Rabeprazole does not accumulate with repeated dosing. Its bioavailability is not influenced by the coingestion of either food or antacids. The pharmacokinetic profile of rabeprazole is substantially altered in the elderly and patients with stable compensated chronic cirrhosis; however, these alterations are not associated with clinically significant abnormalities in laboratory parameters or serious adverse events. The influence of severe decompensated liver disease on the pharmacokinetics of rabeprazole has not been assessed. The pharmacokinetic profile of rabeprazole is not significantly altered by renal dysfunction requiring maintenance haemodialysis. These findings suggest that dosage adjustment is not required in these special patient populations. Caution should be exercised, however, in patients with severe liver disease.
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PMID:Review article: the pharmacokinetics of rabeprazole in health and disease. 1049 24

Wilson's disease is an autosomal recessive disorder of copper metabolism resulting from the absence or dysfunction of a copper transporting P-type ATPase encoded on chromosome 13. This ATPase is expressed in hepatocytes where it is localized to the trans-Golgi network and transports copper into the secretory pathway for incorporation into ceruloplasmin and excretion into the bile. Under physiologic circumstances, biliary excretion represents the sole mechanism for copper excretion, and thus affected individuals have progressive copper accumulation in the liver. When the capacity for hepatic storage is exceeded, cell death ensues with copper release into the plasma, hemolysis, and tissue deposition. Presentation in childhood may include chronic hepatitis, asymptomatic cirrhosis, or acute liver failure. In young adults, neuropsychiatric symptoms predominate and include dystonia, tremor, personality changes, and cognitive impairments secondary to copper accumulation in the central nervous system. The laboratory diagnosis of Wilson's disease is confirmed by decreased serum ceruloplasmin, increased urinary copper content, and elevated hepatic copper concentration. Molecular genetic analysis is complex as more than 100 unique mutations have been identified and most individuals are compound heterozygotes. Copper chelation with penicillamine is an effective therapy in most patients and hepatic transplantation is curative in individuals presenting with irreversible liver failure. Elucidation of the molecular genetic basis of Wilson's disease has permitted new insights into the mechanisms of cellular copper homeostasis.
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PMID:Wilson's disease. 1107 1

Wilson's disease, an autosomal recessive disorder of copper transport, usually presents with symptoms from the liver or central nervous system. Rarely, the initial manifestation is fulminant hepatic failure. The abnormal gene (ATP7B) is located on chromosome 13q and encodes a copper-transporting ATPase. A large number of mutations have been reported. We describe a previously healthy 16-year-old girl who presented with fulminant hepatic failure. The girl died within 24 h of admission to a hospital from refractory shock. Autopsy revealed cirrhosis and widespread necrosis of the liver. The copper content of the liver was markedly increased (975 micrograms/g dry weight), strongly suggesting a diagnosis of Wilson's disease. Genetic studies revealed that the girl was homozygous for the mutation 2007 del7, which is the mutation found in all Wilson's disease patients previously identified in Iceland. This is the first known case of fulminant hepatic failure due to Wilson's disease in Iceland. Despite the same mutation, the clinical picture is vastly different from other Icelandic patients with Wilson's disease, who all presented with relatively late-onset neurological disease. This suggests that factors other than the specific mutation have significant impact on the phenotype of the disease.
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PMID:Genotype-phenotype interactions in Wilson's disease: insight from an Icelandic mutation. 1133 76

In normal humans, plasma dopamine levels rise during head-out water immersion or saline intravenous infusion. Dopamine inhibits Na+,K+-ATPase activity in the proximal tubule and blunts aldosterone secretion leading to increased diuresis and natriuresis. The aim of this study is to evaluate the role of endogenous dopaminergic activity in the intrarenal sodium handling in patients with compensated liver cirrhosis. We studied nine healthy controls and 12 patients with Child-Pugh A cirrhosis during a normosodic diet for (1) dopaminergic activity, as measured by the incremental aldosterone responses 30 and 60 min after intravenous metoclopramide administration; (2) basal plasma levels of active renin and aldosterone; (3) 4-hr renal clearance of lithium (an index of fluid delivery to the distal tubule), creatinine, sodium, and potassium, first without and then with dopaminergic blockade with intravenous metoclopramide. The patients displayed greater endogenous dopaminergic activity, evidenced by higher incremental aldosterone responses compared with controls (+30 min: 160.2 +/- 68.8 vs 83.6 +/- 35.2 pg/ml, P < 0.01; +60 min: 140.5 +/- 80.3 vs 36.8 +/- 39.1 pg/ml, P < 0.01, respectively). In spite of this, patients and controls did not show significantly different basal aldosterone plasma levels, delivery of sodium to the distal nephron, or urinary excretion of sodium. In both groups the dopaminergic blockade with metoclopramide determined no change in sodium and potassium urinary excretion, but it caused a fall of the fluid and sodium delivery from the proximal tubule to the distal nephron among the patients (from 30.7 +/- 9.3 to 14.4 +/- 4.5 ml/min, P < 0.001; and from 4.25 +/- 1.30 to 2.00 +/- 0.64 meq/min, P < 0.001, respectively). In this group the natriuresis was maintained due to a reduction of the reabsorbed fraction of the distal sodium delivery (from 97.5 +/- 1.9% to 89.8 +/- 12.4%, P < 0.05). In conclusions, compensated cirrhotic patients display an increased endogenous dopaminergic activity compared with controls. This function is critical in maintaining the delivery of sodium to the distal nephron.
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PMID:Dopaminergic control of renal tubular function in patients with compensated cirrhosis. 1185 57

Liver cirrhosis is a chronic disease associated with sodium retention due to increased tubular sodium reabsorption. However, the exact tubular site of increased sodium reabsorption in uncertain. We have recently demonstrated selective hypertrophy of the inner stripe of the outer medulla (ISOM) in rats with liver cirrhosis induced by common bile duct ligation (CBL). The present study was designed in order to measure Na-K-ATPase activity in the two major tubular segments located in the ISOM: the thick ascending limb of henles (MTAL) and the collecting ducts (OMCD) in CBL rats. Sham-operated rats were used as controls. In addition, the natriuretic response to amiloride (0.2 mg kg(-1) h(-1) i.v) was examined in conscious, chronically instrumented rats during conditions where amiloride-induced volume losses were replaced continuously using a servo-controlled i.v. volume replacement system. For 4-5 weeks after CBL, cirrhotic rats showed sodium retention relative to control rats without any sign of ascites. Plasma levels of sodium and aldosterone were normal, but plasma vasopressin was increased. Effective renal plasma flow was significantly increased, whereas glomerular filtration rate (GFR) and renal lithium handling were normal. The CBL rats showed a blunted natriuretic response to amiloride (DeltaFE(Na): 1.17 +/- 0.15% vs. 1.65 +/- 0.13%; P < 0.05). In rats with CBL, Na-K-ATPase activity per mm tubular length was decreased in the OMCD and unchanged in the TAL segment. These results suggest that increased tubular sodium reabsorption in liver cirrhotic rats with early sodium retention is localized in segments proximal to the collecting ducts.
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PMID:Collecting duct function in liver cirrhotic rats with early sodium retention. 1210 Mar 63

The role of the isoprenoid pathway in gastrointestinal and hepatic diseases, and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with (i) acid peptic disease, (ii) ulcerative colitis, (iii) gallstones, (iv) cryptogenic cirrhosis liver, (v) Reye's syndrome, (vi) mesenteric artery occlusion, (vii) irritable bowel syndrome, and (viii) in individuals with right hemispheric, left hemispheric, and bihemispheric dominance: 1. plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; 2. tryptophan/tyrosine catabolic patterns; 3. free radical metabolism; 4. glycoconjugate metabolism; and 5. membrane composition. In patients with gastrointestinal and hepatic disease there were elevated digoxin synthesis, increased dolichol, and glycoconjugate levels, and low ubiquinone and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites in the serum. There was an increase in cholesterol: phospholipid ratio and a reduction in the glycoconjugate level of RBC membrane in these groups of patients. The same biochemical patterns were obtained in individuals with right hemispheric dominance. An upregulated isoprenoid pathway and hyperdigoxinemia is characteristic of gastrointestinal and hepatic disease and in right hemispheric chemical dominance. Right hemispheric chemical dominance is important in deciding the predisposition to gastrointestinal and hepatic disease.
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PMID:Hypothalamic digoxin, cerebral chemical dominance, and regulation of gastrointestinal/hepatic function. 1269 Oct 2


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