Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0008370 (cholestasis)
 9,378 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microsomal preparations from 22 surgical specimens of normal, cholestatic or severely diseased human liver were analyzed with respect to the amounts of cytochromes P-450 and b5 and NADPH-cytochrome c reductase present. Normal human liver contained slightly less NADPH-cytochrome c reductase and cytochrome P-450 (mean 102.6 +/- 14.6 nmol/mg of protein per min. and 0.60 +/- 0.10 nmol/mg of protein, respectively) than is found in the adult rat, but wide variations were observed. Cytochrome b5 was present in comparable amounts to that in rat liver, and cytochrome b5/P --450 ratios were slightly increased in human liver as compared with rat liver. Cholestatic liver did not show significant alterations in the specific contents of any of these three components of the microsomal mixed-function oxidase system, but the two livers with severe parenchymal disease showed substantial reductions in all three. In vitro investigations of cofacter interrelationships in the N-demethylation of ethylmorphine by human liver microsomes suggested that NADPH was the favored electron donor, but NADH had a substantial (ca. 20%) synergistic effect (which was not enhanced by cyanide addition). These observations are in keeping with cytochrome b5 having a possible role in cytochrome P-450-mediated drug hydroxylation in man in both the normal state and after onset of cholestasis.
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PMID:The hepatic microsomal mixed-function oxidase system in man: cofactor effects and the influence of cholestasis. 19 27

Serum glutamic oxaloacetic transaminase (GOT), mitochondrial GOT (GOTm), glutamic-pyruvic transaminase (GPT) and glutamate dehydrogenase activities were determined in 43 healthy controls and in 280 cases of liver diseases. A simplified column chromatographic method coupled with UV assay was employed for separation of GOTm. The activity was measured by following decrease in abosrbance of NADH at 340 nm. The lowest activity of GOTm determined with a coefficient of variation below 10% was 6 mIU/ml. High GOTm activities were found in acute hepatitis (acute stage), subacute hepatitis and primary biliary cirrhosis and were generally associated with high total GOT (GOTt) activities. The activity ratio of GOTm/GOTt varied depending on the stage and severity of liver diseases. The GOTm/GOTt ratio was decreased in acute, fulminant and subacute hepatitides. No significant reduction in the ratio was found in bile duct obstruction, alcoholic liver injury or metastatic liver cancer. Although relatively high GOTm/GOTt ratios were found in some patients with severe hepatic injury, they had no definite association with poor prognosis. These results indicate that the marked elevation in GOTt over GPT in advanced chronic hepatitis, liver cirrhosis and primary hepatoma was mainly due to preferential leakage of cytoplasmic GOT (GOTs).
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PMID:The mechanism of the release of hepatic enzymes in various liver diseases. 1. Alterations in cytoplasmic and mitochondrial enzyme activities in serum. 22 31

Diethyl maleate is a compound which binds with glutathione by means of a glutathione S-transferase and is excreted into bile leading to a rapid depletion of hepatic glutathione. In the rabbit, the activity of the enzyme is fairly low and we were thus prompted to study the possible effects of diethyl maleate on biliary secretion and metabolic status in this species. The administration of diethyl maleate induced a transient choleresis followed by cholestasis. The choleresis coursed with increases in the biliary output of sodium and unaccounted anions, whereas those of chloride, bicarbonate and bile acids were unaffected. Our data seem to confirm that choleresis is due to the osmotic activity of diethyl maleate compounds excreted into bile, as has been reported in rats and dogs. The cholestasis observed coursed with falls in the outputs of sodium, chloride and bicarbonate though that of bile acids remained constant. Following diethyl maleate administration, a metabolic acidosis appeared with progressive increases of blood lactate concentration. In bile the concentration of this anion closely followed that of plasma. The cholestasis is attributed to a lowered biliary secretion of bicarbonate probably secondary to the metabolic alteration. The hepatic values of cytoplasmatic and mitochondrial NADH/NAD ratios and of adenine nucleotide concentrations suggest that the increase in blood lactate results rather from a fall in its hepatic utilization that from an increase in its production.
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PMID:Changes in biliary secretion and lactate metabolism induced by diethyl maleate in rabbits. 309 47

A direct spectrophotometric assay for determination of the serum bile acid concentration in the woodchuck (Marmota monax) has been validated. The assay relies on the conversion of 3-hydroxy bile acids to 3-oxo bile acids by 3 alpha-hydroxysteroid dehydrogenase with concomitant reduction of NAD+ to NADH. Reduction of NAD+ is coupled via a diaphorase catalyst to the formation of a diformazan dye from nitrotetrazolium blue and the diformazan product is measured spectrophotometrically at 540 nm. Interfering endogenous dehydrogenase activity present in woodchuck sera was inactivated with sodium pyruvate. Mean recovery of seven exogenous bile acids added to woodchuck sera was 102.0 +/- 2.2%. Intra-assay precision was determined with ten replicate samples giving a mean +/- standard error of the mean of 1.94 +/- 0.12 micron/L with a coefficient of variation of 3.9%. The mean serum bile acid concentration determined in 33 clinically healthy animals was 5.52 +/- 0.81 micron/L. The serum bile acid concentration increased following surgical ligation of the bile duct from 3.78 +/- 0.58 micron/L to a maximum value of 148.0 +/- 30.7 micron/L and remained increased for the 42 day study period. In woodchucks treated with carbon tetrachloride, the serum bile acid concentration peaked at 16 hours following treatment at 72.7 +/- 29.3 micron/L, and returned to pretreatment concentration within 6 days. The serum bile acid concentration therefore appears to be a sensitive biochemical test of cholestasis and hepatocellular forms of hepatic injury and of potential value in the clinical assessment of hepatic disease associated with woodchuck hepatitis virus infection.
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PMID:Serum bile acid determination for assessment of hepatic injury in the woodchuck. 359 95

A newborn female, the second child of consanguineous parents, exhibited general muscle hypotonia, apathy, hepatomegaly and failure to thrive from birth and signs of craniofacial dysmorphia were present. Pipecolic and trihydroxicoprostanoic acid were excreted in the urine and serum transferrin, ferritin and iron were markedly elevated. At the age of 7 weeks the baby died of respiratory insufficiency. Besides malformations of the brain, renal cysts, liver damage with hypoplastic intrahepatic bile ducts and cholestasis, increased storage of iron and cytochemically proven deficiency of peroxisomes in liver and kidney, morphological studied provided evidence of a mitochondrial myopathy in striated muscle with the accumulation of enlarged bizarre mitochondria, showing only minor structural abnormalities. No defects of NADH-reductase, succinate-dehydrogenase or cytochrome-c-oxidase were demonstrated histochemically. Cytochemical-ultrastructural investigation of mitochondrial ATPase revealed activation of the ATP-synthesising enzyme even before the addition of an uncoupler, this indicating loosely coupled oxidative phosphorylation. In addition a high rate of subcellular autophagy with segregation of mitochondria and focal loss of fibrils was present. Muscle damage in Zellweger syndrome appears to be the consequence of complex, interacting metabolic processes. The mitochondrial myopathy thereby induced allows a better understanding of general muscle hypotonia, one of the leading symptoms of this disorder.
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PMID:Mitochondrial myopathy with loosely coupled oxidative phosphorylation in a case of Zellweger syndrome. A cytochemical-ultrastructural study. 614 41

Mitochondrial enzymes in rat livers or intestines were investigated in experimental models with ethanol- or other hepatotoxic agent-induced liver injuries and extrahepatic cholestasis. In clinical experiment, activities of mitochondrial GOT (mGOT) and ornithine carbasmyl transferase (OCT) were examined in alcoholisms and patients with other various liver diseases. Results obtained are as follows; 1) The activities of OCT and mGOT were increased particularly at onset of acute hepatitis, in chronic active hepatitis and intrahepatic cholestasis, showing that mitochondria were injured strikingly in these diseases. The activities in alcoholics were not so great, however mGOT/total-GOT ratio was increased in level than in other diseases. 2) Changes in mitochondrial enzymes of rat liver treated with ethanol were too varied to catch the actual tendency in this pathologic state. 3) Administration of galactosamine, carbon tetrachloride, or alpha-naphthyl isothiocyanate (ANIT) caused a significant fall in activities of succinate cytochrome C reductase and OCT, along with increase in serum activity of OCT, indicating severe mitochondrial injury with these drugs. Extrahepatic cholestasis following bile duct ligation showed the same changes of mitochondrial enzymes in liver tissue and serum. 4) These data indicate that observation of activities of serum OCT, mGOT, along with mGOT/total-GOT ratio are useful for estimation of mitochondrial damage in extra- and intra-hepatic cholestasis, and acute or chronic active hepatitis. The changes in alcoholic fatty liver was not so subtle as compared with other liver diseases. 5) It is surmized that smooth endoplasmic reticulum was increased in content and pentose phosphate shunt was inhibited by chronic ethanol treatment, estimating from increased activities of NADH-ferricyanide reductase and gamma-glutamyl transpeptidase, and decreased activity of glucose-6-phosphate dehydrogenase. 6) The changes in hepatic enzymes with ethanol treatment were paralleled with those of intestinal ones, indicating that metabolic changes in intestine contribute someway in the formation of alcoholic fatty liver. 7) Chronic ethanol treatment induced lowered active transport in intestinal mucosa, which indicates inhibition in absorption of various nutrients by ethanol.
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PMID:[Experimental and clinical studies on enzymes of mitochondria in various liver diseases; with special reference to alcoholic liver disease (author's transl)]. 625 Sep 59

Elevated levels of bile acids are thought to play an important role in the renal failure of patients with obstructive jaundice undergoing surgery. In contrast, ursodeoxycholic acid (UDA) is widely used to improve cholestasis and has been proposed as protective bile acids and antioxidant. The present study employs kidney fragments to determine the role of reactive oxygen species (ROS) in the mechanism of toxicity of hydrophobic bile acids and to determine the nephroprotectant properties of UDA against the hydrophobic bile acids. The hydrophobic bile acids chenodeoxycholic (200 microM) and deoxycholic acid (200 microM) significantly (P<0.05) increased lactate dehydrogenase leakage (LDH) from glomerular fragments from 2.7+/-0.4 to 5.03+/-0.23 and 4.66+/-0.37 (micromol NADH consumed/min/mg protein) for chenodeoxycholic and deoxycholic acid respectively. Preincubating the fragments with UDA (500 microM) did not prevent the leakage of LDH caused by the bile acids. The level of lipid peroxidation was not increased in fragments exposed to either ursodeoxycholic (0-500 microM), lithocholic (0-100 microM), chenodeoxycholic (0-500 microM) or deoxycholic acid (0-500 microM). Furthermore UDA (500 microM) did not prevent the increase in lipid peroxidation caused by tert-butyl hydroperoxide (0-1000 microM) in the fragments. These results suggest that hydrophobic bile acids do not cause lipid peroxidation in kidney fragments and that UDA is neither capable of preventing the loss of membrane integrity induced by hydrophobic bile acids or acting as an antioxidant in kidney fragments.
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PMID:The role of ursodeoxycholic acid in bile acid-mediated kidney fragment toxicity. 1004 11

Adult-onset type II citrullinemia (CTLN2), characterized by a liver-specific deficiency of urea cycle enzyme, argininosuccinate synthetase, is caused by mutations in SLC25A13 that encodes a calcium binding mitochondrial solute carrier protein, citrin. Citrin deficiency causes not only CTLN2 but also neonatal intrahepatic cholestasis caused by citrin deficiency at neonatal period. Moreover citrin and its isoform aralar were found to be aspartate glutamate carrier. From the viewpoint of the metabolic functions of citrin as aspartate glutamate carrier in urea synthesis and NADH shuttle, symptoms of CTLN2 and neonatal intrahepatic cholestasis caused by citrin deficiency are analyzed.
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PMID:Pathogenesis and pathophysiology of citrin (a mitochondrial aspartate glutamate carrier) deficiency. 1260 10

Deficiency of citrin due to mutations of the SLC25A13 gene causes adult-onset type II citrullinemia (CTLN2) and one type of neonatal intrahepatic cholestasis (NICCD). About half of the NICCD patients are detected based on high galactose, phenylalanine, and/or methionine concentrations on newborn mass screening (NMS). To clarify the perinatal and neonatal effects and the inconsistent results on NMS, we examined aminograms, the levels of bile acids and galactose in dried blood spots for NMS from 20 patients with NICCD. Birth weight was low for gestational age (-1.4 +/- 0.7 SD). Affected fetuses may have suffered intrauterine citrin deficiency. The first abnormality detected after birth was citrullinemia, and 19 of 20 patients had citrulline levels higher than +2 SD of controls. Tyrosine, phenylalanine, methionine, galactose, and bile acids were less affected than citrulline on d 5 after birth. Galactose and bile acids levels were increased at 1 mo in comparison with d 5 after birth due to impairment of the cytosolic NADH reducing-equivalent supply into mitochondria of hepatocytes. Patients with negative findings on NMS had low levels of total 20 amino acids. Citrulline/serine, citrulline /leucine plus isoleucine, and citrulline/total amino acids ratios, controlled for the confounding effect of low amount of total amino acids, were higher in all patients than +2 SD, +2 SD, and +3 SD of controls, respectively. NMS for citrin deficiency (frequency of homozygote with SLC25A13 mutation: 1/10,000-1/38,000 in East Asia) will be useful for clarification of the clinical course, treatment, and prevention of this disease.
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PMID:Effects of citrin deficiency in the perinatal period: feasibility of newborn mass screening for citrin deficiency. 1529 82

Citrin, encoded by SLC25A13, is a liver-type mitochondrial aspartate-glutamate carrier (AGC), of which deficiency, in autosomal recessive trait, causes neonatal intrahepatic cholestasis (NICCD) and adult-onset type II citrullinemia (CTLN2). NICCD patients have jaundice, hypoproteinemia, hypoglycemia, galactosemia, growth retardation, fatty liver and multiple aminoacidemia including citrulline, methionine, threonine and tyrosine. Some of the neonates who have experienced NICCD suffer from severe CTLN2 more than 10 years or several decades later. In CTLN2, neuropsychotic symptoms such as disorientation, aberrant behavior, coma and death are observed. Laboratory findings reveal hyperammonemia, citrullinemia, fatty liver and liver-specific decrease in a urea cycle enzyme, argininosuccinate synthetase (ASS). In some cases, hyperlipidemia, pancreatitis and hepatoma are accompanied with CTLN2. Citrin as a liver-type AGC plays a role in supplying aspartate to the cytosol for urea, protein and nucleotide synthesis by exchanging mitochondrial aspartate for cytosolic glutamate and proton, and transporting cytosolic NADH reducing equivalent to mitochondria as a member of malate aspartate shuttle essential for aerobic glycolysis. AGC is also important for gluconeogenesis from lactate. Although it is difficult to explain pathogenesis of the symptoms such as cholestasis in NICCD and liver-specific decrease of ASS protein in CTLN2 from the functions of the AGC, some are understandable by the loss of citrin functions. Many CTLN2 patients have been treated with a low protein and high carbohydrate diet and glycerol at the hyperammonemic coma. We argue that those treatments may result in fatty liver, hyperlipidemia, hyperammonemia and even death due to loss of the citrin functions. Loss of citrin first cause deficiency of aspartate in the cytosol, which results in an increase in cytosolic NADH/NAD(+) ratio and then activation of fatty acid synthesis pathway to compensate the aberrant ratio. This follows inhibition of fatty acid oxidation. The peculiar fondness for food of CTLN2 patients who like protein and dislike carbohydrate and sweets may be related to their metabolic requirements.
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PMID:Metabolic derangements in deficiency of citrin, a liver-type mitochondrial aspartate-glutamate carrier. 1619 99


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