Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In human and experimental CCl4-liver damage, S-adenosyl-l-methionine-synthetase and/or the intrahepatic content of S-adenosyl-l-methionine, are diminished and in human cirrhosis phospholipid methyltransferase is markedly reduced. Therefore the aim of this study was to investigate the effect of S-adenosyl-l-methionine administration on liver damage induced by 15-day bile duct ligation. Liver damage was analyzed by histological, ultrastructural and biochemical techniques. Biliary obstruction produced an increase in collagen content, dilation of the bile canaliculi and disorganization of mitochondria. These effects were not observed in the bile-duct-ligated group receiving S-adenosyl-l-methionine. Biochemical results showed that bile duct ligation increased serum bilirubins, and alkaline phosphatase and gamma-glutamyl transpeptidase activities. These effects were prevented significantly by S-adenosyl-l-methionine. On the other hand, glycogen content in the liver was depleted while lipid peroxidation was increased by biliary obstruction, S-adenosyl-l-methionine administration prevented these effects. In the bile-duct-ligated group, hepatocyte and erythrocyte plasma membrane Na+/K+ and Ca(2+)-ATPase were lower than in the control group (p < 0.05). Administration of S-adenosyl-l-methionine preserved ATPase activities. The exogenous S-adenosyl-l-methionine supply is probably responsible for restoring transmethylation lost in liver diseases.
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PMID:Protective effect of S-adenosyl-l-methionine on liver damage induced by biliary obstruction in rats: a histological, ultrastructural and biochemical approach. 796 28

The hepatoprotective effect of the ethanol/water (1:1) extract of Eclipta alba (Ea) has been studied at subcellular levels in rats against CCl4-induced hepatotoxicity. Ea significantly counteracted CCl4-induced inhibition of the hepatic microsomal drug metabolising enzyme amidopyrine N-demethylase and membrane bound glucose 6-phosphatase, but failed to reverse the very high degree of inhibition of another drug metabolising enzyme aniline hydroxylase. The loss of hepatic lysosomal acid phosphatase and alkaline phosphatase by CCl4 was significantly restored by Ea. Its effect on mitochondrial succinate dehydrogenase and adenosine 5'-triphosphatase was not significant. The study shows that hepatoprotective activity of Ea is by regulating the levels of hepatic microsomal drug metabolising enzymes.
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PMID:Hepatoprotective effects of Eclipta alba on subcellular levels in rats. 814 70

Following the earlier observation that inhalation of volatile lipid solvents and of narcotic gases causes cholestasis, we studied the effects of various organic solvents on bile flow, plasma membrane fluidity and potassium movement in rat liver. Both in vivo and in the isolated perfused liver, applications of CCl4, CHCl3, dichloromethane, trichloroethylene, halothane, benzene and cyclohexane elicited rapid and sustained but reversible cholestasis. A transient phase of choleresis was observed prior to and after cholestasis, during the increase and fall in liver tissue solvent concentrations, respectively. Tissue concentrations required to produce cholestasis were lower the higher the lipophilicity of the solvent. Membrane fluidity was measured in isolated basolateral liver cell membranes by fluorescence polarization. Fluidity increased with increasing solvent concentration, the increase being associated with either biphasic stimulation and inhibition of membrane enzymes (Na+,K(+)-ATPase, 5'nucleotidase) or with inhibition alone (Mg(2+)-ATPase). In the isolated perfused liver, application of organic solvents caused hepatic uptake of K+ that was followed by K+ release upon withdrawal of the solvent. The magnitude of K+ uptake elicited by the solvent was comparable with the effect of blocking K+ channels with 2 mM Ba2+, but Ba2+ was ineffective in the presence of the solvent. In contrast, application of ouabain caused K+ release in equal amounts in the absence and presence of the solvent, indicating that K+ uptake elicited by the solvent results from inhibition of K+ efflux through K+ channels rather than stimulation of the Na+,K+ pump. The data show that cholestasis elicited by lipid solvents is associated with an increase in membrane fluidity and with disturbance of liver K+ homeostasis. The significance of these observations is discussed with respect to other models of experimental cholestasis.
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PMID:Organic solvents increase membrane fluidity and affect bile flow and K+ transport in rat liver. 821 71

Interferons are recognized to inhibit collagen production. Since fibrosis has been associated with liver dysfunction, we investigated the effects of alpha-interferon on the function and lipid composition of hepatocyte and erythrocyte plasma membranes derived from CCl4-cirrhotic male Wistar rats. In both cell types, CCl4 decreased Na+/K+ and Ca(2+)-ATPase activity and increased the cholesterol to phospholipids (CH/PL) ratio (p < 0.05). Administration of interferon (80,000 IU/kg s.c. for 8 weeks) increased survival from 40 to 90%, and preserved normal ATPase activity and CH/PL ratio. Our results show that administration of alpha-interferon to CCl4-cirrhotic rats improves survival, and liver and erythrocyte membrane function and composition, probably as a result of its antifibrogenic effect.
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PMID:Effect of alpha-interferon on erythrocyte and hepatocyte plasma membranes derived from cirrhotic rats. 830 89

Transmethylation is an important means of altering the biological activity of a wide variety of compounds. In human and experimental CCl4-liver cirrhosis the intrahepatic content of S-adenosyl-L-methionine (SAM), an active methyl donor, and the SAM-transmethylase activity are markedly reduced. Previously, it has been reported that SAM administration preserves hepatocyte plasma membrane Na+/K(+)-ATPase and Ca(2+)-ATPase activities in cirrhotic rats. Therefore, the aim of this work was to study the effect of SAM administration on the membrane lipid composition and the ATPase activity on erythrocytes derived from CCl4-cirrhotic rats. Male Wistar rats were used in these experiments. In group 1, cirrhosis was induced by i.p. administration of CCl4. Animals of group 2 received, in addition to CCl4, three daily doses of SAM (20 mg kg-1, i.m.). Group 3 consisted of cirrhotic animals that, after 8 weeks of CCl4 treatment, received SAM (20 mg kg-1, i.m., three times daily) for 4 weeks without discontinuation of CCl4. Group 4 included animals treated with SAM alone. Seventy-two hours after the end of treatment the rats were anaesthetized, blood was collected by heart puncture and the erythrocyte plasma membranes were isolated. The Na+/K(+)- and (Ca2+ +Mg2+)-ATPase activities and the cholesterol (CH) and phospholipid (PL) contents were determined in the plasma membranes. The Na+/K(+)- and Ca(2+)-ATPase activities were both significantly decreased (twofold) in the CCl4-treated group as compared to controls. Administration of SAM completely prevented this fall in both ATPases. In group 4, the Na+/K(+)-ATPase activity was partially restored but the Ca(2+)-ATPase activity was completely restored.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:S-adenosyl-L-methionine prevents and reverses erythrocyte membrane alterations in cirrhosis. 839 94

The alteration of the plasma membrane (Ca(2+)-Mg2+)-ATPase activity in the liver of rats administered orally carbon tetrachloride (CCl4) solution was investigated. Rats received a single oral administration of CCl4 (10, 25 and 50%, 1.0 ml/100 g body weight), and 3 or 24 h later they were sacrificed. CCl4 administration caused a remarkable elevation of liver calcium content and a corresponding increase in liver plasma membrane (Ca(2+)-Mg2+)-ATPase activity, indicating that the increased Ca2+ pump activity is partly involved in calcium accumulation in liver cells. Moreover, the participation in regucalcin, which is an intracellular activating factor on the enzyme, was examined by using anti-regucalcin IgG. The plasma membrane (Ca(2+)-Mg2+)-ATPase activity increased by CCl4 administration was not entirely inhibited by the presence of anti-regucalcin IgG (1.0 and 2.5 ug/ml) in the enzyme reaction mixture. However, the effect of regucalcin (0.25-1.0 uM) to activate (Ca(2+)-Mg2+)-ATPase in the liver plasma membranes of normal rats was not revealed in the liver plasma membranes obtained from CCl4-administered rats. Also, the effect of regucalcin was not seen when the plasma membranes were washed with 1.0 mM EGTA, indicating that the disappearance of regucalcin effect is not dependent on calcium binding to the plasma membranes due to liver calcium accumulation. Now, the presence of dithiothreitol (5 mM) or heparin (20 ug/ml) caused a remarkable elevation of the plasma membrane (Ca(2+)-Mg2+)-ATPase activity in the liver obtained from CCl4-administered rats. Thus, the regucalcin effect differed from that of dithiothreitol or heparin. The present study suggests that the impairment of regucalcin effect on Ca2+ pump activity in liver plasma membranes is partly contribute to hepatic calcium accumulation induced by liver injury with CCl4 administration.
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PMID:Activatory effect of regucalcin on hepatic plasma membrane (Ca(2+)-Mg2+)-ATPase is impaired by liver injury with carbon tetrachloride administration in rats. 879 Dec 79

We investigated the changes in the ability of adenosine triphosphate (ATP) synthesis in the inner mitochondrial membrane with the acute and chronic liver injuries by carbon tetrachloride (CCl4) in rats. The ability of ATP synthesis was evaluated by measuring the activity of proton ATPase and the ability of oxygen consumption using isolated mitochondria. In the acute liver injury, the ability of ATP synthesis at 6 hr after injection was preserved relatively well in spite of hepatocyte injuries. On the other hand, at 12 hr after CCl4 injection, the necrosis of hepatocyte was widely recognized. In the chronic liver injury, severe fibrosis was induced but the ability of ATP synthesis was kept as well as that in the normal liver. These results suggest that the mitochondria have some resistivity against radicals produced by CCl4.
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PMID:Changes in the ability of ATP synthesis in the mitochondrial membrane in the rat liver injured by carbon tetrachloride. 880 59

Colchicine is one of the most promising drugs for the treatment of cirrhosis. However, due to its toxicity, other drugs are being evaluated and colchicine-like molecules may be good alternatives. The aim of this work was to compare the beneficial effects of colchicine and trimethylcolchicinic acid (a colchicinoid less toxic than colchicine) on CCl4-cirrhosis. The drugs were administered either through CCl4 administration (8 weeks) or after CCl4 intoxication for 4 weeks at a dose of 10 micrograms/rat/day, orally. Liver plasma membranes were isolated for high affinity Ca(2+)-ATPase, gamma-glutamyl transpeptidase and alkaline phosphatase activities. The activities of gamma-glutamyl transpeptidase and alkaline phosphatase were also measured in serum. Liver glycogen content and a marker for lipid peroxidation were determined in liver samples. We found that both compounds preserved and significantly reversed high affinity Ca(2+)-ATPase, gamma-glutamyl transpeptidase and alkaline phosphatase plasma membrane and serum enzyme activities as well as the hepatic glycogen content.
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PMID:Effect of colchicine and trimethylcolchicinic acid on CCl4-induced cirrhosis in the rat. 893 57

Swiss albino rats were treated in groups with CCl4, and flyash to induce cellular toxicity in the lungs and trachea. Animal groups received treatment of Koflet (K) with CCl4 (7 days) and with flyash (30 days); their general health and biochemical parameters were studied and used as an indication of cellular injuries. A significant loss was observed in body weight and food consumption in animals given only CCl4 or flyash, while simultaneous treatment with K resulted in a non significant alteration from normal control groups. Enzyme (alkaline phosphatase, Ca2+ -Mg2+ -ATPase, glutamic-oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT)) activities were estimated in tissue homogenate preparation of lung, trachea and serum, which showed no significant change except for GPT activity as compared to control animals which received CCl4 or flyash with K. Similarly lung, trachea and serum contents of carbohydrate, protein, sialic acid, serum protein, serum cholesterol were estimated and it was found that alteration caused by CCl4, or flyash becomes almost non-significant compared to that of the control after the treatment of K, except for carbohydrate and serum cholesterol values. The animal group which was only treated with K did not show any significant alteration in their biochemical markers or injuries, except for cholesterol.
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PMID:In vivo protective role of Koflet (an ayurvedic preparation) against cellular toxicity caused by CCl4 and flyash. 940 99

There is some anecdotal evidence that oxygen-ozone therapy may be beneficial in some human diseases. However so far only a few biochemical and pharmacodynamic mechanisms have been elucidated. On the basis of preliminary data we postulated that controlled ozone administration would promote an oxidative preconditioning preventing the hepatocellular damage mediated by free radicals. Six groups of rats were classified as follows: (1) negative control, using intraperitoneal sunflower oil; (2) positive control using carbon tetrachloride (CCl4) as an oxidative challenge; (3) oxygen-ozone, pretreatment via rectal insufflation (15 sessions) and after it, CCl4; (4) oxygen, as group 3 but using oxygen only; (5) control oxygen-ozone, as group 3, but without CCl4; group (6) control oxygen, as group 5, but using oxygen only. We have evaluated critical biochemical parameters such as levels of transaminase, cholinesterase, superoxide dismutase, catalase, phospholipase A, calcium dependent ATPase, reduced glutathione, glucose 6 phosphate dehydrogenase and lipid peroxidation. Interestingly, in spite of CCl4 administration, group 3 did not differ from group 1, while groups 2 and 4 showed significant differences from groups 1 and 3 and displayed hepatic damage. To our knowledge these are the first experimental results showing that repeated administration of ozone in atoxic doses is able to induce an adaptation to oxidative stress thus enabling the animals to maintain hepatocellular integrity after CCl4 poisoning.
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PMID:Ozone oxidative preconditioning: a protection against cellular damage by free radicals. 979 40


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