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)

5'-Nucleotidase, assayed as 5'-AMPase, has been extensively characterized and established as a stable, quantitative plasma membrane marker in HeLa S3 cells. The membrane 5'-AMPase has a Km of 7.0 microM. Relative affinities of the other 5'-mononucleotides for the enzyme are 5'-GMP > 5'-TMP > 5'-UMP > 5'-CMP. There are activity optima at pH7 and 10; the latter is Mg(2+)-dependent. The membrane preparations have a small amount of acid phosphatase activity that is distinct from 5'-AMPase activity but no alkaline phosphatase. AOPCP, ADP, and ATP are strongly inhibitory. Mg2+, Ca2+, or Co2+ additions do not affect the pH 7.0 activity; Mn2+ activates slightly, whereas Zn2+, Cu2+, and Ni2+ are inhibitory. EDTA slowly inactivates, but removal of the EDTA without the addition of divalent cations restores activity. The inactivation is also substantially reversed by Co2+ or Mn2+, but reactivability by divalent cations decreases with time in EDTA. ConA strongly inhibits, and alpha-methyl-D-mannoside or glucose (the latter much less efficiently) relieves the inhibition, indicating that the 5'-AMPase is a glycoprotein. Histidine is also inhibitory. Ouabain, phloretin, cytochalasin B, cysteine, phenyl-alanine, MalNEt, and IAA are without effect. 5'-AMPase activity codistributes with pulse-bound [3H]ouabain when either of two cell fractionation procedures are used. The 5'-AMPase activity per cell is constant at different cell densities in exponentially growing cells, and activity per unit cell volume remains constant throughout the cell cycle. These properties, together with its absence in other organelles, its stability to storage, its insensitivity to certain experimental manipulations, and its general insensitivity to inhibitors of specific transport systems, make 5'-AMPase a useful quantitative marker in studies on the regulation of HeLa membrane transport systems. Key Words: HeLa, 5'-nucleotidase, plasma membrane marker, non-specific phosphatases, divalent ions, ConA, AOPCP, cell cycle, mitochondria, transport inhibitors.
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PMID:Characterization of HeLa 5'-nucleotidase: a stable plasma membrane marker. 4 80

The effects of diphenylhydantoin (DPH) and ouabain were studied in vitro on Mg-ATPase, Ca-ATPase and alkaline phosphatase (AlPase) in isolated brush borders from rat jejunum, and in vivo on intestinal calcium absorption. Vitamin D-deficient, -repleted and normal rats were used in this study. Repletion of deficient animals with vitamin D restored Ca-ATPase activity and AlPase activity partly. Ca-absorption was normalized by repletion with the vitamin. DPH greatly stimulated Ca-ATPase activity in vitro and Ca-absorption in vivo, but it inhibited AlPase activity. Mg-ATPase was not affected by vitamin D, nor by DPH. Ouabain had no consistent effect on any of the parameters studied. It was concluded that Ca-ATPase, and not AlPase, is involved in the transport of calcium through the jejunal microvillous membrane, and that DPH enhances Ca-absorption by activation of Ca-ATPase.
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PMID:Stimulation of vitamin D-dependent Ca-ATPase and of intestinal caldium absorption by diphenylhydantoin. 12 71

To elucidate the possible toxicity of heavy metals in a renal tubular epithelial cell line derived from a normal cynomolgus female monkey (JTC-12, P3 (F], the effects of HgCl2, Na2CrO4 and NiCl2 on the dome formation and the release of intrinsic enzymes from the cells were studied. The results were as follows: 1. The JTC-12. P3(F) cells showed an evident dome formation when an inducer of differentiation (hexamethylene bisacetamide or N, N-dimethylformamide) was added to the medium. 2. Ouabain inhibited the dome formation of the JTC-12. P3(F) cells, suggesting that the dome formation is dependent on the active transepithelial transport of Na+. 3. The addition of 40 microM HgCl2, 10 microM Na2CrO4 or 20 microM NiCl2 inhibited the dome formation. 40 microM HgCl2, 10 microM Na2CrO4 or 150 microM NiCl2 caused significant cell death. 4. The addition of 5 microM HgCl2, 1 microM Na2CrO4 or 20 microM NiCl2 resulted in an increased release of lactate dehydrogenase into the medium for 6 hours. 20 microM HgCl2, 1 microM Na2CrO4 or 20 microM NiCl2 increased the medium gamma-glutamyl transpeptidase concentration for 6 hours, but 40 microM HgCl2, 5 microM Na2CrO4 or 100 microM NiCl2 did not cause a significant increase in the medium alkaline phosphatase concentration. The results suggest that the JTC-12. P3(F) cells possess, at least in part, functional characteristics similar to the other kidney proximal tubular cells and that the inhibition of dome formation and enzyme release from the cells may be the early indicators that predict metal toxicity to the cells.
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PMID:[Application of renal epithelial cell culture in study of organ toxicity of heavy metals]. 279 95

Alterations in ouabain inhibitable Na-K ATPase activity, polyol pathway activity, and myoinositol metabolism are part of a unifying hypothesis proposed to explain the pathogenesis of the chronic complications of diabetes mellitus. Direct measurements of renal ouabain inhibitable Na-K ATPase activity in animals with streptozotocin-induced diabetes show increased or decreased activity, depending on the nephron segment examined and the duration of diabetes. While myoinositol feeding corrects depressed Na-K ATPase activity in peripheral nerve of streptozotocin diabetic rats, the effect of myoinositol feeding on altered renal Na-K ATPase activity is unknown. To assess the effect of experimental diabetes on renal ouabain inhibitable Na-K ATPase activity and test the involvement of the polyol/inositol pathway, we assayed kidneys from normal, streptozotocin diabetic, and myoinositol-supplemented diabetic rats for renal ouabain-inhibitable Na-K ATPase, alkaline phosphatase, and tau-glutamyltranspeptidase (tau-GT) activity. Ouabain inhibitable Na-K ATPase activity, expressed per milligram of protein, is increased in the inner medulla of the diabetic kidney compared with normal and, expressed per microgram DNA, is increased in both the inner medulla and cortex. Myoinositol supplementation did not affect the increase in renal enzyme activity seen with streptozotocin diabetes. These observations suggest that the regulation of renal ouabain inhibitable Na-K ATPase activity, in streptozotocin diabetes, does not depend on supplemental myoinositol. These findings do not exclude the possibility that changes in polyol or myoinositol concentrations in a specific nephron segment may have pathogenetic significance for diabetic nephropathy.
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PMID:Renal ouabain inhibitable Na-K ATPase activity and myoinositol supplementation in experimental diabetes mellitus. 289 13

The distribution and activities of phosphatases and oxidative enzymes have been determined with the help of histochemical methods in the kidney of the Prussian Carp, a stenohaline freshwater-fish. In addition to fish maintained in freshwater aquaria, a group of the animals used has been adapted to seawater of moderate salinity. The following pattern of enzyme reaction intensities has been observed in the various kidney structures: Strong reactions of alkaline phosphatase in the nephron are confined to the glomerular capillary convolute and the brush border of proximal segments. Equally enzyme activities are observed in the connective tissue sheath of the collecting duct -- archinephric duct system. Acid phosphatase can be detected in all segments of the nephronic tubule, strong activities are found in the proximal segment (P I), in the epithelium of the archinephric duct, and, especially, in the interstitial tissue. ATPase reacts strongly positive in epithelial cells of the distal tubule and the collecting duct -- archinephric duct system. ATPase reactions are inhibited by Ouabain, and therefore can be regarded as reactions of Na--K-ATPase. Mitochondrially bound oxidative enzymes, connected with the citric acid cycle and the respiratory chain, show very strong reaction intensities in the distal tubule and the collecting duct- archinephric duct system, while the glomeruli generally exhibit negative reactions. Lactate -- and malate dehydrogenases are found to react weakly to negatively throughout the whole kidney. Maintenance in seawater does not deeply affect the enzyme pattern of the kidney of the Prussian carp, with exception of some oxidative enzymes, reacting weaker in the distal tubule and the collecting duct-archinephric duct system. In addition, the epithelial cells of the archinephric duct of seawater adapted fish show a marked apical localization of reaction products for these enzymes. Possible relations between enzyme histochemistry and fish kidney physiology are discussed, in connection with comparative aspects of the enzyme histochemistry of the vertebrate kidney. A short review of normal histology and function of the kidney of the Prussian carp is added.
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PMID:[Phosphatases and oxidative enzymes in the kidney of the Prussian carp (Carassius auratus gibelio Bloch) adapted to salt water]. 625 47

1. Incubation of Schistosoma mansoni for 5 min in a phosphate-buffered medium, pH 7.4, released tegumental material containing the following phosphohydrolase activities: alkaline phosphatase, 5'-nucleotidase, glycerol-2-phosphatase, glucose 6-phosphatase, phosphodiesterase and ATPase. 2. Maximum activity of these enzymes was measured at pH 9.5; however, the phosphodiesterase and ATPase activities were also appreciable at pH 7.0. 3. Solubilization of the released tegumental material in 1% Triton X-100 followed by gel filtration distinguished three peaks of enzyme activity: an ATPase (mol.wt. greater than 1000 000), a phosphodiesterase (mol.wt. 1 000 000) and an alkaline phosphomonoesterase with broad specificity (mol.wt. 232 000). 4. The ATPase activity was highly activated by 10 mM-Mg2+ or 1 mM-Ca2+ and was inhibited by chelating agents. Ouabain, Na+ and K+ had little effect on enzyme activity, whereas activity was increased by 50% in the presence of calmodulin. The phosphodiesterase activity was highest in the presence of 100 mM-Na+ or -K+, and 10 mM-Mg2+ or -Ca2+. Alkaline phosphatase activity was also stimulated by 100 mM-Na+ or -K+, and 10 mM-Mg2+; however Ca2+ inhibited at greater than 1 mM. 5. Surface iodination of parasites followed by detergent solubilization and gel filtration of the released tegumental membranes indicated that these enzymes were not accessible. A major surface component, apparent mol.wt. 80 000, was iodinated. 6. Rabbit anti-(mouse liver 5'-nucleotidase) antibodies did not inhibit the phosphohydrolase activities. However, an immunoglobulin G fraction from sera of mice chronically infected with S. mansoni partially inhibited alkaline phosphatase activity, but was without effect on the phosphodiesterase and ATPase activities. 7. The location of the enzymes in the double membrane of the tegument and their significance in host-parasite interactions is discussed.
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PMID:Properties of a series of tegumental membrane-bound phosphohydrolase activities of Schistosoma mansoni. 627 49

The effects of l and d-, p-bromotetramisole (pBTM) on alkaline phosphatase were studied in relation to 45Ca2+, 32phosphate and 3H-thymidine uptakes in non-mineralizing second (M2) and mineralizing first (M1) maxillary hamster molar tooth germs under the conditions of organ culture. At the concentration used in culture (10(-3)M), l-pBTM completely inhibited alkaline phosphatase activity in tooth germ homogenates. About 30% of the enzyme activity was inhibited by d-pBTM at the same concentration. In culture, there were no significant differences between the effects of l and d-pBTM isomers on all the parameters measured. In the non-mineralized M2 molars, l and d-pBTM significantly reduced both TCA-soluble and TCA-insoluble 32phosphate uptakes but not 45Ca2+. However, 3H-thymidine uptake was also significantly decreased. In M1 molars, the pBTM isomers significantly reduced the uptake of TCA-soluble 32phosphate and 45Ca2+ but not TCA-insoluble 32phosphate. Ouabain, a specific inhibitor of Na+-K+-ATPase (but not alkaline phosphatase), also significantly reduced 3H-thymidine uptake to the same extent as the pBTM isomers in the non-mineralizing M2 molars, but it did not significantly affect either 32phosphate (TCA-soluble and TCA-insoluble) or 45Ca2+ uptake. Although this inhibitor significantly reduced both 45Ca2+ and TCA-soluble 32phosphate uptake in the mineralizing M1 molars, this effect was much less dramatic than was the case with the pBTM isomers. The reduced 45Ca2+ uptake in the M1 molars is probably a consequence of reduced mineralization since in the non-mineralizing M2 molars calcium uptake was not significantly affected by the pBTM isomers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies of alkaline phosphatase inhibition by p-bromotetramisole in non-mineralizing and mineralizing neonatal hamster tooth germs in vitro. 658 Nov 67

This study was carried out to determine the effect of renal ischaemia on transport systems for organic compounds in the rabbit kidney proximal tubule. Ischaemia for 30 or 60 min. induced glucosuria and phosphaturia, which was accompanied by polyuria and natriuresis. The Na(+)-dependent uptake of glucose, succinate and L-glutamate by brush-border membrane vesicles was not altered by 30 or 60 min. of ischaemia, while the H+/tetraethylammonium antiport was significantly inhibited after 30 min. of ischaemia. When the duration of ischaemia was extended to 120 min. the uptake of glucose and succinate by brush-border membrane vesicles was also significantly attenuated, but the L-glutamate uptake was not altered. The uptake of glucose, succinate and L-glutamate by basolateral membrane vesicles was not impaired even with 120 min. of ischaemia, suggesting that transport systems for organic compounds in the brush-border membrane are more sensitive to ischaemia than those in the basolateral membrane. Ouabain-sensitive oxygen consumption in renal cortical slices was not depressed by 60 min. of ischaemia. When kidneys were reperfused for 60 min. following 60 min. of ischaemia, the Na(+)-glucose and Na(+)-succinate cotransport and the H+/tetraethylammonium antiport were not different from the control, but the recovery of alkaline phosphatase was significantly reduced. When kidneys were subjected to ischaemia for 60 min., a loss of brush-border microvilli and plasma membrane was observed after 5 or 60 min. of reflow in the proximal convoluted tubule. After 3 hr of reflow, focal necrosis appeared although the microvilli were partially regenerated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of renal ischaemia on organic compound transport in rabbit kidney proximal tubule. 858 2

In an attempt to understand the mechanism underlying the tissue-dependent function, the expression of NHE-1 protein and its sub cellular localization was examined in the rat GI-tract and other tissues. Rat NHE-1 polyclonal antibodies were raised in rabbits using a NHE-1 fusion protein antigen. The antibodies recognized a 110 kD protein in rats and mice, but not in human or rabbit RBCs. Colon, stomach, brain, spleen and kidney expressed NHE-1 protein abundantly, whereas the skeletal muscle the least abundant. Ouabain-sensitive-K+-stimulated p-nitrophenylphosphatase (PNPPase), the partial activity of the sodium pump and alkaline phosphatase (Apase) were used as the markers of the basolateral and apical membranes. NHE-1 was detected predominantly in the PNPPase enriched membrane fractions, but was also detected in the apical membrane enriched fractions in the kidney cortex, jejunum and colon at a lower level. NHE-1 was detected in the plasma membrane enriched fractions from the skeletal muscle and ventricle. Immunofluorescence data showed a similar localization pattern of NHE-1 in the colon and kidney sections. These findings suggest that NHE-1 is localized both on the apical and basolateral membrane. In view of its similar sub cellular localization in the GI-tract and kidney, but a different level of expression, might suggest that the level of protein, but not the sub cellular distribution is important to regulate its tissue-dependent function.
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PMID:Expression and sub cellular localization of the sodium hydrogen exchanger isoform-1 in rat tissues: a possible functional relevance. 1135 47