Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pancreatic duct fragments were isolated from rat and hamster pancreas and were cultured in an agarose matrix for up to 8 weeks (rat) or 20 weeks (hamster). The fragments consisted predominantly of duct epithelium, lesser numbers of stromal and atrophied acinar cells, and small numbers of islet cells. Hamster ducts averaged 3 micrograms protein per duct while rat ducts averaged 1 microgram, and the protein:DNA ratio of both types of ducts was less than that of whole pancreas. Estimated average duct yields of 6% (hamster) and 1% (rat) were based on the protein content of the ducts. Duct viability was shown by the incorporation of 3H-thymidine and 3H-leucine into bulk DNA and protein and by autoradiography. gamma-Glutamyl transferase and (Na + K)-ATPase specific activities were slightly elevated while amylase was depressed in the ducts when compared with whole pancreas in both species. gamma-Glutamyl transferase was localized histochemically in both duct epithelium and in surviving acinar tissue, as seen in vivo. Amylase was shown by immunohistochemistry to be present within duct lumina and in atrophied acini and their lumina. Alkaline phosphatase and Mg-ATPase specific activities were elevated in the hamster, but reduced in the rat, when compared with whole pancreas. Hamster alkaline phosphatase and Mg-ATPase were localized by histochemistry to the duct stroma, where these enzymes are not detected in vivo. Carbonic anhydrase was found in the duct epithelium of both species, as in vivo, as well as in the duct stroma, unlike in vivo. Acid glycosaminoglycans, as revealed by alcian blue staining, were found at the apical surfaces and in the lumina of both kinds of ducts. Glutathione-S-transferase and glucose-6-phosphate dehydrogenase were elevated in rat ducts, but not in hamster ducts. The polypeptide compositions of cultured ducts, freshly isolated pancreatic islets, and whole pancreas were compared by one-dimensional sodium dodecyl sulfate polyacrylamide gradient gel electrophoresis. No duct-specific polypeptides were observed; the ducts were characterized mainly by the reduction or absence of polypeptides, including some zymogens, seen in whole pancreas.
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PMID:Biochemical and histochemical characterization of cultured rat and hamster pancreatic ducts. 244 50

We tested the hypothesis that depletion of intracellular glutathione (GSH) during heat shock results in protein thiol oxidation, thereby increasing thermal sensitivity. Depletion of GSH was accomplished using a combination of diethylmaleate and buthionine sulfoximine and protein sulfhydryls were measured using two independent methods. Chinese hamster ovary (CHO) cells were solubilized in polyacrylamide gel electrophoresis (PAGE) sample buffer containing 3-(N-maleimido-propionyl) biocytin, separated by sodium dodecyl sulfate (SDS)-PAGE, electroluted onto nitrocellulose, and visualized via avidin-alkaline phosphatase staining. A second method utilized 5,5'-dithiobis(2-nitrobenzoic acid) to measure protein solubilized in SDS. The results indicate that when CHO cells are heated at 43 degrees C GSH depletion can increase thermal sensitivity but does not cause nonspecific protein thiol oxidation at this temperature or at 37 degrees C.
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PMID:Measurement of protein thiols after heat shock using 3-(-N-maleimido-propionyl) biocytin labeled proteins separated by SDS-PAGE and electroluted onto nitrocellulose: thiol blotting. 249 69

We recently found that exposure of cells to different aminothiols promotes cystine uptake and leads to an increase of cellular glutathione by new biosynthesis (Issels et al., Biochem. Pharmacol., 37: 881-888, 1988). Therefore, we further investigated whether the known radioprotective and chemoprotective aminothiol derivative S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) or its dephosphorylated form (WR-1065) will lead to similar effects. In order to convert WR-2721 to the free thiol compound (WR-1065) in vitro, the medium also contained 20 U/ml alkaline phosphatase (AP). For uptake studies a modified McCoy's 5A medium supplemented with 0.1 mM [35S]cystine was used. In Chinese hamster ovary (CHO) and Chinese hamster ovarian carcinoma (OvCa) cells, WR-2721 exposure alone did not increase the cystine uptake relative to that of control (untreated) cells, while WR-2721 + AP enhanced the uptake of cystine more than twofold in both cell lines. The increase of cystine uptake was dependent on the time of exposure (0-60 min) and the concentrations of WR-2721 (0-8 mM) + AP. Half-maximal uptake of cystine was observed at concentrations of 0.69 and 0.57 mM WR-2721 in CHO and OvCa cells, respectively. Determination of both reduced (GSH) and oxidized (GSSG) cellular glutathione levels after the exposure (0-300 min) to WR-2721 + AP in CHO cells showed a depletion of GSH to less than 10% of the pretreatment value and a 4-fold reduction of the GSH/GSSG ratio. In contrast, in OvCa cells the amount of total glutathione rather increased with no significant change of the GSH/GSSG ratio by the exposure to WR-2721 + AP. Further analysis using high-performance liquid chromatography of cell extracts revealed that the relative amount of incorporated [35S]-cystine into glutathione was increased similarly in both cell lines. The data show that precursor availability and new biosynthesis of glutathione is enhanced by the exposure to WR-2721 + AP in vitro despite the differential modulation of the cellular glutathione status in the two cell lines. These findings may have important implications for the use of aminothiols like WR-2721 in various cells and tissues in regard of their response to chemotherapeutic agents, ionizing radiation and/or hyperthermia.
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PMID:Promotion of cystine uptake, increase of glutathione biosynthesis, and modulation of glutathione status by S-2-(3-aminopropylamino)ethyl phosphorothioic acid (WR-2721) in Chinese hamster cells. 253 52

Acid and alkaline phosphatase changes in various parts of the central nervous system (olfactory bulbs, cerebral hemispheres, cerebellum, medulla oblongata, and spinal cord) were analyzed during methylmercury chloride (MMC) treatment with a dose of 5 mg/kg/day body weight. The drug was subcutaneously introduced into the animals and the enzymes were analyzed after 2, 7, and 15 days' treatment. One group of animals was treated for seven days and kept without drug for another seven days (withdrawal group). The antagonizing capacities of four chelators, namely, N-acetyl-DL-homocysteine thiolactone (NAHT), D-penicillamine (DPA), glutathione (GSH), and sodium selenite (SEL), were also analyzed in relation to the restoration of enzymes. Study results show a linear inhibition of acid and alkaline phosphatases with increasing duration of MMC treatment. However, the magnitude of enzymatic inhibition is different in different brain areas. After 15 days' treatment, maximum inhibition of acid and alkaline phosphatases was recorded in the spinal cord and cerebellum, respectively. Chelators also exhibited differential recovery of the enzymes in various animal groups, as well as in discrete brain areas. No uniformity in the recovery of the enzymes with chelators was observed. However, study results show that biochemical parameters are good indicators of early recognition of neurotoxicity.
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PMID:A therapeutic profile of metal chelators in the detoxication of methylmercury chloride inhibited acid and alkaline phosphatases in different areas of the central nervous system of rats. 256 Nov 58

The stability and storage characteristics were studied of 11 bovine enzymes of potential clinical significance, namely, aldolase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, acetylcholinesterase, creatine kinase, gamma glutamyltransferase, glutathione peroxidase (GSH-Px), alpha-hydroxybutyrate dehydrogenase, lactate dehydrogenase and superoxide dismutase (SOD). Enzyme activities in fresh serum were compared with those in plasma containing various anticoagulants including lithium heparin, EDTA and oxalate/fluoride. The same preservatives were assessed for their effects on the whole blood activities of GSH-Px and SOD. Stabilities of enzymes in plasma and serum stored at room (+20 degrees C), refrigerator (4 degrees C) or deep freeze (-20 degrees C) temperatures were also compared. In addition, SOD and GSH-Px activities in samples stored, at the same temperatures, as whole blood or aqueous lysates were monitored.
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PMID:Stability and storage characteristics of enzymes in cattle blood. 286 28

The stability and storage characteristics were studied of 11 ovine enzymes of potential clinical significance, namely, aldolase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, acetylcholinesterase, creatine kinase, gamma glutamyltransferase, glutathione peroxidase (GSH-Px), alpha-hydroxybutyrate dehydrogenase, lactate dehydrogenase and superoxide dismutase (SOD). Enzyme activities in fresh serum were compared with those in plasma containing various anticoagulants including lithium heparin, EDTA and oxalate/fluoride. The same preservatives were assessed for their effects on the whole blood activities of GSH-Px and SOD. Stabilities of enzymes in plasma and serum stored at room (+20 degrees C), refrigerator (4 degrees C) or deep freeze (-20 degrees C) temperatures were also compared. In addition, SOD and GSH-Px activities in samples stored, at the same temperatures, as whole blood or aqueous lysates were monitored. The results are discussed with particular reference to the differences between sheep and cattle.
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PMID:Stability and storage characteristics of enzymes in sheep blood. 286 29

Previous methods to deplete in vivo concentrations of reduced glutathione (GSH) have not been able to lower tissue GSH levels for extended periods, have been toxic, and can alter the metabolism of xenobiotics. A possible alternative to lower in vivo concentrations of GSH may be the use of buthionine-S,R-sulfoximine (BSO) in the drinking water of laboratory animals to inhibit the biosynthesis of GSH. It has been previously reported that 20 mM BSO in the drinking water given to mice was able to lower GSH levels in a variety of tissues after 15 days. In order to more fully characterize the in vivo depletion of GSH in tissues by ingestion of BSO and determine if this method would be suitable in studies requiring depressed levels of GSH for extended periods, we added different amounts of this agent to the drinking water given to mice for various times up to 28 days. We found that ingested BSO at the highest concentration used in drinking water (30 mM) was able to maximally lower GSH concentrations in mouse lungs, lung lavage fluid, liver, kidneys, and blood to 59.0 +/- 3.6%, 35.0 +/- 5.1%, 44.3 +/- 1.5%, 69.5 +/- 3.9%, and 70.0 +/- 6.0% of control mice, respectively, for up to 28 days. These lowered concentrations of tissue GSH returned to control levels after mice were returned to untreated drinking water for 7 days. The potential toxicity of such treatments was also evaluated. Levels of alkaline phosphatase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, glutathione peroxidase, and glutathione reductase in lungs and lung lavage fluid, and total and differential cell counts from lung lavage fluid were not different between control and BSO-treated mice. This showed that BSO treatment did not produce indications of lung injury as measured by these biochemical parameters. Serum aspartyl transferase and gamma-glutamyl transpeptidase activities were unaffected by the BSO treatments, indicating normal liver functions. Lung and liver cytochrome P-450 concentrations were also not different between controls and BSO-treated animals. Thus, BSO in the drinking water of mice was able to effectively lower in vivo levels of GSH without eliciting acute toxic responses.
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PMID:Effects of the long-term depletion of reduced glutathione in mice administered L-buthionine-S,R-sulfoximine. 286 40

The effect on liver tissue of glutathione administration to rats treated for 7-14 days with 2-acetylaminofluorene was investigated. The DNA damage induced by the hepatotoxic agent and evaluated by the alkaline elution technique was significantly reduced by glutathione. Furthermore, GSH administration maintained liver GSH level, prevented the increase in alkaline phosphatase and reduced the decrease in glucose-6-phosphatase activity. GSH did not significantly influence the increase in gamma-glutamyl-transpeptidase and glutathione-S-transferase activities.
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PMID:Effect of glutathione on alterations of liver DNA structure and metabolic activities induced in vivo by 2-acetylaminofluorene. 288 May 50

Substitution reactions with biologic nucleophiles appear to govern the antitumor and toxic properties of platinum complexes. In this paper we have characterized the reactions of several platinum antitumor agents with sulfur-containing amino acids, peptides, proteins, and nonbiologic nucleophiles. The rate constants for the reactions of trans-diamminedichloroplatinum(II) (trans-DDP), cis-diamminedichloroplatinum(II) (DDP), diammine (1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) and cis-diisopropylamine-cis-dichloro-trans-dihydroxy platinum(IV) (CHIP) with cysteine (Cys), methionine (Met), and glutathione (GSH) were determined at 37 degrees. A reactivity ratio of 1:1.5:22:6500 was determined for the reaction of GSH with CHIP, CBDCA, DDP, and trans-DDP respectively. The rate constant for the binding of DDP to DNA, 7.4 X 10(-5) sec-1, decreased to 5.9 X 10(-5) sec-1 and 1.7 X 10(-5) sec-1 in the presence of 0.5 and 5 mM GSH respectively. The products formed in the reaction of GSH with trans-DDP, DDP, and CBDCA were also examined. Under conditions of high platinum concentration (2-3 mM), CBDCA and DDP form large molecular weight species with GSH as indicated by 1H-NMR and ultrafiltration experiments. The complex [Pt(GSH)2 X 3H2O]n was isolated from the reaction of 3 mM DDP with 6 mM GSH. The product formed in the reaction of 3 mM trans-DDP with 6 mM GSH was not macromolecular in nature, and 1H-NMR spectra revealed that platinum was bound to the Cys sulfhydryl group. Rate constants were determined for the reactions of these platinum complexes with diethyldithiocarbamate (DDTC) and thiosulfate, two agents known to reduce platinum-mediated nephrotoxicity. DDTC, but not thiosulfate, was shown to rapidly chelate platinum from [Pt(GSH)2 X 3H2O]n. The effects of DDP, CBDCA, and CHIP on the sulfhydryl-dependent rat renal proximal tubule membrane enzymes alkaline phosphatase (AP), gamma-glutamyltranspeptidase (GGTP), leucine aminopeptidase (LAP), and the Na+/K+- and Mg2+-adenosine-5'-triphosphatases (ATPases) were also investigated in vitro. The ability of platinum complexes to inhibit these enzymes parallels their reactivity with other nucleophiles. DDTC and thiourea were shown to restore activity to platinum-inhibited enzymes. Chloride ion was found to reduce platinum-mediated enzyme inhibition in an unpredictable manner, the greatest effect being observed with LAP and GGTP and the least with the ATPases. None of these renal enzymes was directly inhibited by DDP in vivo.
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PMID:Characterization of the reactions of platinum antitumor agents with biologic and nonbiologic sulfur-containing nucleophiles. 295 56

The synergistic hepatotoxicity of dietary disulfiram (DSF) with 1,2-dichloroethane (DCE) subchronically administered by inhalation at three concentration levels (150, 300, and 450 ppm) was studied. The criteria for hepatotoxicity were treatment-related increases in serum activities of sorbitol dehydrogenase, 5'-nucleotidase, and alkaline phosphatase, and in liver-to-body weight ratios. DSF alone did not elicit these responses while DCE at the highest concentration level increased liver-to-body weight ratios and the activity of 5'-nucleotidase. Exposure to DSF alone decreased cytochrome P450 levels, but in combination with DCE, the decrement of cytochrome P450 was additive in a DCE concentration-dependent manner. However, depression of cytochrome P450 by DCE alone was not concentration dependent. Although DSF and DSF/DCE combination increased the activity of glutathione S-transferases (GSTs), both DSF and DCE singly and in combination increased the tissue levels of reduced glutathione (GSH). Evidence is presented showing that the potentiation of the hepatotoxicity of DCE observed in the presence of DSF may be due to an inhibition of microsomal mixed-function oxidase-mediated metabolism of DCE and to a compensatory increase in DCE metabolism to reactive metabolites generated by GST-mediated conjugation of DCE with GSH.
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PMID:Interaction between 1,2-dichloroethane and tetraethylthiuram disulfide (disulfiram). II. Hepatotoxic manifestations with possible mechanism of action. 378 26


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