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)

Four factors which stimulate collagen synthesis and prolyl hydroxylase activity in cultures of human and mouse fibroblasts have been isolated by molecular sieve chromatography from animal and human fibrotic and cirrhotic livers. These factors do not stimulate protein or DNA synthesis or total DNA in these cultures. It has also been shown that these factors, designated collagen stimulating factors F1-F4, do not owe their activity to ascorbate or glutamine. Collagen stimulating factors are heat stable, and F1 and F2 have apparent molecular weights of about 4000 and 1000 respectively. Since these factors are not present in normal animal or human liver it is suggested that they may be responsible for increased collagen production in vivo in hepatic fibrosis and cirrhosis.
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PMID:Collagen stimulating factors in hepatic fibrogenesis. 632 76

The altered plasma amino acid pattern (i.e. increased levels of aromatic amino acids and decreased levels of branched chain amino acids) is a characteristic feature of cirrhotic patients. Recently it has been proved that an increased net degradation of BCAA is positively correlated to the plasma NH3 level, strongly suggesting that these amino acids are molecularly involved in glutamine synthesis to detoxify ammonia in skeletal muscle. Lactulose, a synthetic, nonabsorbable disaccharide, is believed to actively promote excretion of ammonia from the body by causing it to be trapped in the acidified fecal stream and making it unavailable for absorption. Therefore therapy with lactulose could determine an increase of BCAA. The present study was undertaken to examine plasma amino acid pattern of ten patients with liver cirrhosis before and after lactulose therapy. No statistically significant changes of amino acids were observed.
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PMID:[Plasma amino acids in patients with liver cirrhosis treated with lactulose]. 652 9

Administration of PAK to patients with hepatic cirrhosis significantly reduced hyperammonaemia and plasma levels of pyruvic and lactic acid. No significant changes in glycaemia were found. PAK treatment increased plasma levels of glutamic acid and decreased plasma levels of glutamine. This double-blind placebo controlled trial showed that PAK administration has a positive effect on some metabolic disturbances in cirrhotic patients.
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PMID:Effect of pyridoxine alpha-ketoglutarate (PAK) on ammonia and pyruvic and lactic acid blood levels in patients with cirrhosis. 667 4

Serum amino acid patterns in patients with different types of hepatic encephalopathy were investigated. Marked elevations in most of serum amino acids observed in untreated patients with acute type of fulminant hepatitis were not remarkable in the patients who have already treated; particularly branched chain amino acids (BCAA), phenylalanine and tyrosine were much lower in the latter group. However, elevation of serum methionine levels and lower ratio of BCAA/(phenylalanine + tyrosine) were similarly observed in both groups. In encephalopathic patients with decompensated cirrhosis, many amino acids such as phenylalanine, tyrosine and methionine were elevated with a slight depressed levels of serum BCAA. Highly significant decrease in serum BCAA levels and no elevation of phenylalanine and methionine with a minimal increase of tyrosine were observed in patients with chronic type of hepatic encephalopathy; other amino acids except for glutamine and arginine were much lower as compared to those in decompensated cirrhotics and even to the control values.
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PMID:Characteristics change in serum amino acid levels in different types of hepatic encephalopathy. 711 80

Femoral arterio-venous (A-V) differences of blood free amino acids and plasma ammonia (NH3) were simultaneously determined after an overnight fast in 16 patients with decompensated liver cirrhosis in the absence and presence of encephalopathy, as compared with those in 8 control subjects. In spite of increased releases of phenylalanine (Phe) and tyrosine (Tyr) from the peripheral tissue, releases of isoleucine (Ile) and leucine (Leu) as well as alanine (Ala) were found to be significantly reduced in decompensated liver cirrhosis, particularly in the presence of hepatic encephalopathy. Furthermore, NH3 was found to be significantly taken up by the skeletal muscle of these patients, and a positive correlation was observed between arterial NH3 level and the A-V differences of Leu, of Ile and of Ala. These findings strongly suggest that net degradation (or utilization) of branched-chain amino acids (in particular, Leu and Ile) is enhanced in the muscle for detoxication of ammonia (i.e., glutamine synthesis) by supplying the carbon skeleton and energy in cirrhosis of the liver.
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PMID:Augmented utilization of branched-chain amino acids by skeletal muscle in decompensated liver cirrhosis in special relation to ammonia detoxication. 722 60

To determine the hepatic fate of alpha-ketoisocaproate (KIC) in cirrhosis, six groups of isolated rat livers were perfused with 0, 0.5, 1 (with or without alpha-[1-14C]KIC), 2, and 5 mM KIC; control livers from healthy rats were studied in parallel under similar conditions. KIC was rapidly removed by the normal livers, whereas uptake was lower in the cirrhotic livers at all concentrations tested (at 2 mM, 4.04 +/- 0.33 vs. 6.32 +/- 0.58 mumol/min; P < or = 0.05). The transamination pathway, evaluated by leucine exchanges, was more important in the cirrhotic livers (25.4 vs. 6.8% in controls at 2 mM). The incorporation of alpha-[1-14C]KIC in proteins of cirrhotic liver was increased compared with controls (0.25 +/- 0.04% of alpha-[1-14C]KIC was incorporated in proteins excreted in perfusate vs. 0.20 +/- 0.04 in controls; P < or = 0.05). In addition, a line of evidence suggests that glutamine rather than glutamate is the N donor for leucine synthesis from KIC. The decarboxylation pathway evaluated by beta-hydroxybutyrate production and by 14CO2 release from alpha-[1-14C]KIC was reduced, respectively, by 40-85% (according to KIC dose) and by 24% at 90 min in cirrhotic livers compared with healthy livers. These results indicate a dramatic modification of KIC metabolism in the cirrhotic liver; its uptake by the liver is decreased and its incorporation into proteins is increased via an enhancement of transamination to leucine, probably as a consequence of an inhibition of branched-chain keto acid dehydrogenase.
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PMID:Metabolism of alpha-ketoisocaproic acid in isolated perfused liver of cirrhotic rats. 786 6

Cirrhosis induced in rats by carbon tetrachloride was used to study alterations in the activities and lobular distribution of carbamoylphosphate synthetase and glutamine synthetase. Specific activity of carbamoylphosphate synthetase in cirrhotic subjects was decreased to 70% of controls. Staining was homogeneous within micronodular areas, but varied from area to area and generally showed a decreased intensity. Specific activity of glutamine synthetase and the size of the glutamine synthetase-positive area were decreased to 20% and less of controls. Glutamine synthetase-positive hepatocytes were rare and scattered at the periphery of nodular areas and within fibrous septa, the normal association with the central veins being widely lost. Rarely, complete micronodules showed a slight homogeneous staining for glutamine synthetase. Arginase activity was not affected, whereas glutaminase activity was enhanced by 50%. Serum levels of ammonia were elevated more than 2-fold and those of glutamine by 30%. In contrast, urea levels tended to be slightly diminished. Serum ammonia levels showed a clear negative correlation with the specific activity of glutamine synthetase and the size of the glutamine synthetase-positive area. Furthermore, blood urea levels correlated with the sum of ammonia and glutamine concentrations, but not with each of these substrate concentrations alone. These data suggest that the changes in activity and distribution of glutamine synthetase contribute to hyperammonemia in cirrhosis. Despite a reduced activity of the initial enzyme of the urea cycle, urea synthesis is not diminished accordingly. This may be due to an enhanced flux caused by the elevated blood level of ammonia and an increased hydrolysis of glutamine, because of higher levels of glutaminase.
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PMID:Changes in distribution and activity of glutamine synthetase in carbon tetrachloride-induced cirrhosis in the rat: potential role in hyperammonemia. 791 4

The impact of hepatic and renal failure on the metabolism of L-alanyl-L-glutamine (Ala-Gln) and glycyl-L-glutamine (Gly-Gln) was investigated in 11 healthy volunteers, five patients with liver cirrhosis, and six patients with chronic renal failure. The clearance (mL.kg-1.min-1) of Ala-Gln was significantly higher than that of Gly-Gln in all three groups. Renal failure significantly reduced clearances of both Ala-Gln and Gly-Gln (13.27 +/- 0.71 and 3.06 +/- 0.28) when compared with control values (21.68 +/- 1.21 and 7.08 +/- 0.38). Liver failure had no significant influence on the clearances of Ala-Gln and Gly-Gln (22.62 +/- 2.89 and 6.20 +/- 0.88). Liver failure delayed and renal failure almost abolished the increases in plasma concentrations of free amino acid residues after peptide injection. It is concluded that other organs can substitute for the peptide-clearing function of the liver, but not of the kidney. Kidney is the most important organ for the clearance of dipeptides and the release of amino acid residues into circulation. Our data show that clearance rates of both Ala-Gln and Gly-Gln are sufficient to avoid accumulation of either peptide if infused in the presently recommended doses. Both Ala-Gln and Gly-Gln could therefore be used as sources for glutamine in parenteral nutrition even in patients with chronic renal failure.
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PMID:Importance of liver and kidney for the utilization of glutamine-containing dipeptides in man. 808 85

The amino acid pattern in the ascites of 79 dogs was examined. The concentration of glutamine in neoplastic ascites is significantly lower than in cardial effusions. In contrast, glutamate is significantly higher in neoplastic ascites than in cardial ascites. Using an arbitrary discrimination value of 0.28 for the glutamate/glutamine ratio, purulent or cardial ascites are easily differentiated, with a sensitivity of 100% and a specificity of 94%. The differentiation is very distinct, with no overlap between the group of patients with liver cirrhosis on the one hand and the groups of patients with purulent peritonitis, heart failure, or malignant ascites on the other hand. There was no diagnostically unsable correlation between the concentrations of the other 20 amino acids and the underlying causes of ascites formation.
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PMID:Glutamine and glutamate in ascitic fluid of dogs. 809 69

This paper documents dose-dependent effects of ornithine aspartate (OA) on postprandial hyperammonemia and plasma amino acids. Ten patients with cirrhosis were randomized to undergo 1 out of 4 infusion series. Each series consisted of four 8-h infusions (09:00 h-17:00 h), with placebo (NaCl), 5 g, 20 g or 40 g of OA being administered on separate days in varying sequences. This 4-fold crossover design was double-blind. On infusion days, patients received 2 oral protein loads (0.25 g/kg at 09:00 h and 0.5 g/kg at 13:00 h). Venous blood samples were drawn every 2 h and the 24-h urine was collected. In addition to measuring plasma ammonia and amino acids, the urea production rate, serum glucose and serum insulin were analyzed. A significant postprandial rise in the ammonia concentration was noted during the infusions of placebo and 5 g of OA but did not occur with the dosages of 20 g (after the second protein load) and 40 g (after both protein loads). Furthermore, the latter dose, compared with placebo, significantly reduced plasma ammonia after the minor protein load. Urea production rate increased when 20 g or 40 g of OA was administered. Of the amino acids involved in the metabolic pathways of ornithine and/or aspartate, glutamate showed a rise in its plasma level following infusion of 40 g of OA, whereas glutamine did not. Concentrations of methionine, phenylalanine, tyrosine, threonine, serine and glycine declined progressively with increasing doses of OA (5-40 g). The highest dose of the drug caused hyperglycemia and hyperinsulinemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of ornithine aspartate on plasma ammonia and plasma amino acids in patients with cirrhosis. A double-blind, randomized study using a four-fold crossover design. 815 Nov 4


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