Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A study of the value of serum enzymes in 184 patients with colorectal cancer has been performed. The enzymes studied were gamma glutamyltransferase (gammaGT), alkaline phosphatase (AP), lactate dehydrogenase (LDH), 5'-nucleotidase (5'-NT), glutathione reductase (GR), alanine and aspartate transaminases. In patients without liver metastases, elevated enzyme levels were found in 11-55% preoperatively. 5'-NT showed the least number of elevated activities, while gammaGT activities were increased in 29% and LDH in 55%. The percentage of elevated enzyme levels rose significantly in the early postoperative period. Patients with liver metastases showed increased enzyme activities in 40-60% preoperatively: gammaGT was the most sensitive indicator. Increased enzyme activity was related to the degree of liver involvement with secondary tumor. With extensive liver metastases, gammaGT levels were increased in 82%. It is concluded that serum enzymes are of limited value in the preoperative detection of liver metastases, and particularly when tumor involvement of the liver is small.
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PMID:Serum enzymes in colorectal cancer. 3 19

Extracellular adenosine has the potential to influence many aspects of target cell metabolism. The present study has determined the endogenous levels of adenosine in the pregnant mouse uterus and developing embryo-decidual unit with respect to the expression of two key enzymes of adenosine metabolism, 5'-nucleotidase (5'-NT; EC 3.1.3.5) and adenosine deaminase (ADA; EC 3.5.4.4). To measure adenosine levels, nucleoside extracts were etheno-derivatized and quantitated by high-performance liquid chromatography-fluorescence detection (0.03 pmol/mg protein sensitivity). Adenosine levels were determined to be 0.18 nmol/mg protein in the nonpregnant uterus; however, two statistically significant changes were identified in the pregnant uterus: (1) a periimplantation surge between day 3 (0.24 nmol/mg protein) and day 5 (0.59 nmol/mg protein) of gestation (plug day 0; implantation day 4); and (2) an early postimplantation decline between day 6 (0.54 nmol/mg protein) and day 7 (0.10 nmol/mg protein). The periimplantation adenosine surge coincided with uterine expression of 5'-NT, an enzyme which catalyzes the irreversible dephosphorylation of 5'-AMP to adenosine. 5'-NT expression was shown by Northern blot analysis to peak in the embryo-decidual unit on day 5 of gestation and then to decline through day 9; transcripts remained elevated in the placenta between day 9 and day 13 (the latest day examined in this study). By use of specific enzyme histochemistry, most 5'-NT activity was localized to the primary decidual zone on day 5. This expression subsequently declined during regression of the primary decidua; however, 5'-NT appeared on giant trophoblast (days 7-13) and the metrial gland (days 11-13). Other purine catabolic enzymes degrading AMP (adenylate deaminase) or generating adenosine (S-adenosylhomocysteine hydrolase) were not detected in the embryo-decidual unit suggesting that the net flux of utero-placental AMP catabolism proceeds with adenosine as an intermediate, this being the major pathway of adenosine formation. The sharp drop in adenosine levels between day 6 and day 7 coincided with a rise in the activity and mRNA expression of ADA, an enzyme which catalyzes the irreversible deamination of adenosine to inosine. ADA was previously localized to the secondary decidual zone (days 6-11), secondary giant cells (days 7-13), and spongiotrophoblasts (days 8-13) in the mouse (Knudsen et al., 1991). Results of developmental Northern blot analysis demonstrated a direct correlation of relative 5'-NT/ADA mRNA band intensity to adenosine content between day 4 and day 9 of gestation, suggesting that the local availability of adenosine in the antimesometrium is dependent upon the distribution of these enzymatic activities.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Adenosine levels in the postimplantation mouse uterus: quantitation by HPLC-fluorometric detection and spatiotemporal regulation by 5'-nucleotidase and adenosine deaminase. 142 25

Ecto-5'-nucleotidase (ecto-5'-NUC, EC 3.1.3.5., CD73) is a plasma membrane enzyme, which catalyzes the hydrolytic dephosphorylation of purine nucleotides to the corresponding nucleosides so that they can pass through the plasma membrane. The distribution of ecto-5'-NUC is heterogeneous, but all blood mononuclear cell (BMC) subpopulations investigated until now have had ecto-5'-NUC activity. Purified natural killer (NK) cells were prepared by fluorescence-activated cell sorting of CD16-positive cells (purity 94%). In purified NK cells the ecto-5'-NUC activity was less than 1 U/10(6) as estimated by a radioisotope method. Using a cytochemical assay, the proportion of cells with activity was less than 1%. The most likely explanation is that NK cells have no ecto-5'-NUC activity and that the very small ecto-5'-NUC activity observed in this study was caused by contaminating non-NK cells. NK cells thus constitute the only BMC subset known without ecto-5'-NUC activity.
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PMID:Natural killer cells lack ecto-5'-nucleotidase. 153 54

Adenosine produced from 5'-AMP has been proposed as a mediator of intrinsic renal regulation. The rates of 5'-AMP and adenosine metabolism are dependent on the activities of enzyme involved in purine metabolism. The activities of adenosine kinase (AK), adenosine deaminase (ADA), 5'-nucleotidase (5'-NT), AMP deaminase, xanthine oxidase and purine nucleoside phosphorylase were measured in cytosolic and membrane fractions from glomeruli, cortical tubules, medullary thick ascending limb of Henle (MTAL) and collecting duct prepared from rat kidney by combinations of sieving and sucrose density gradient centrifugation techniques. In the cytoplasm of glomeruli cells, the activity ratios of ADA/AK and AMP deaminase/5'-NT were 70 and 2.4, respectively. The highest activity of 5'-NT was found in membrane fractions of cortical tubules where it was equally distributed between luminal and antiluminal membranes. Membrane fractions of MTAL did not contain detectable amounts of adenosine deaminase activity. The highest activity of xanthine oxidase and purine nucleoside phosphorylase was in the cytoplasm fraction of glomeruli. These results suggest that deamination of AMP and adenosine may be favored in the cytoplasm of glomeruli cells. In contrast, in the extracellular space of glomeruli and especially in the cortical tubule, AMP can be converted preferentially to adenosine by 5'-NT.
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PMID:The distribution of enzymes involved in purine metabolism in rat kidney. 161 Aug 88

In the lymphocytes infected in vitro with BLV (bovine leukemia virus) the contents of Ca2+ and Mg2+ were determined using roentgen microanalyser JXA-5 A Joel-form (Japan). In the smears prepared from these cells the activity of enzyme markers of cell membranes i.e. alkaline phosphatase (AP - EC 3.1.3.1), 5'-nucleotidase (5'-NT - EC 3.1.3.5) and adenosine-triphosphatases - Ca2+ and Mg2+ dependent (ATP-ase - EC 3.6.1.3) was determined. The decrease in AP and ATP-assess activity and increase in 5'-NT in the membranes of leukemic lymphocytes were observed. During these changes the increase in Ca2+ and decrease in Mg2+ ions occurred. These processes lead to clear disturbances in the metabolism of cells transformed by the neoplasm. The effect of this phenomenon is probably the opening of calcium canals with the following cytoplasmatic hypercalcemia. It's very destructive for the change in permeability of the membrane of lymphocytes.
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PMID:[The content of Ca2+ and Mg2+ ions and membrane enzyme activity (AP, 5'-NT, ATPases) in the lymphocytes infected in vitro with bovine leukemia virus]. 166 9

Serum alkaline phosphatase (AKP), gamma-glutamyl transpeptidase (gamma-GT), 5'-nucleotidase (5'-NT), leucine aminopeptidase (LAP), AKP gamma-GT isoenzymes, and lipoprotein-X (LP-X) were measured in 97 normal pregnant women and 40 patients with intrahepatic cholestasis of pregnancy (ICP). It was found that in ICP the changing patterns in the four hepatobiliary enzymes were different in different gestational weeks of 3 rd trimester. The changes of gamma-GT and 5'NT were more significant, especially the latter. Six bands were found both in serum AKP and gamma-GT isoenzymes. In ICP the rate of occurrence of AKP1 and AKP2 isoenzymes were elevated. Thus, gamma-GT, 5'-NT, AKP and gamma-GT isoenzymes might be more sensitive parameters for monitoring intrahepatic cholestasis of pregnancy.
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PMID:[Changes in hepatobiliary enzymes and its isoenzymes in intrahepatic cholestasis in pregnancy]. 167 17

Functional studies were performed on human peripheral blood T lymphocytes stained with goat anti-5'-nucleotidase antibodies and separated into ecto-5'-nucleotidase (ecto-5'-NT)-positive and -negative populations using the FACSTAR fluorescence-activated cell sorter. On the average, ecto-5'-NT+ T cells contained 34 +/- 13% CD4+ and 55 +/- 15% CD8+ cells, whereas ecto-5'-NT-T cells contained 65 +/- 12% CD4+ and 23 +/- 8% CD8+ cells. Staining with anti-5'-NT antibodies did not significantly alter the ability of unseparated T cells to proliferate in response to PHA or PMA, or in a MLR. However, prior incubation with anti-5'-NT antibodies did inhibit the ability of irradiated T cells to provide help for PWM-stimulated Ig synthesis by as much as 55%. In five separate experiments, ecto-5'-NT-T cells demonstrated an equal or better ability to incorporate [3H]TdR after PHA stimulation or in a MLR, as compared with ecto-5'-NT+ T cells. Similarly, ecto-5'-NT- T cells were not diminished in their ability to provide help for autologous B cells in a PWM-driven system. Clearly, the inability of ecto-5'-NT- T cells from patients with a variety of immunodeficiency diseases to function in these assays cannot be explained solely by their lack of ecto-5'-NT activity. In contrast, ecto-5'-NT-positive and -negative T cells showed markedly different dose-response curves for proliferation in response to PMA. Ecto-5'-NT+ T cells responded to lower doses of PMA (1.0 ng/ml) than did ecto-5'-NT- T cells and showed a two- to eight-fold greater rate of [3H]TdR incorporation at 3 to 10 ng of PMA per ml. Ecto-5'-NT+ T cells may have a protein kinase C that is more accessible or more easily activated or may utilize an alternate pathway of activation when stimulated with low concentrations of PMA.
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PMID:Functional characterization of ecto-5'-nucleotidase-positive and -negative human T lymphocytes. 253 56

Human peripheral blood T cells were stimulated to proliferate when cultured with submitogenic doses of PMA and goat antibodies to 5'-nucleotidase (5'-NT). The degree of proliferation, as measured by [3H]TdR incorporation on day 3, was similar to that achieved by stimulation with PHA. Anti-5'-NT antibodies had no effect on PHA-induced proliferation. Maximal stimulation was achieved with 0.6 to 1.0 ng/ml of PMA and 125 micrograms/ml of IgG isolated from a goat anti-5'-NT antiserum. Both intact IgG and F(ab')2 fragments were stimulatory. IL-2R expression and IL-2 secretion were also induced by anti-5'-NT antibodies and PMA. Anti-5'-NT-induced proliferation was inhibited greater than 95% by a murine anti-IL-2 receptor mAb and required less than 0.3% monocytes. Similar results have been obtained with a murine mAb specific for 5'-NT. As expected, anti-5'-NT antibodies and PMA did not induce the proliferation of ecto-5'-NT-T cells isolated by cell sorting. Pretreatment of total T cells with phosphatidylinositol-specific phospholipase C removed an average of 89% of the 5'-NT activity from the cell surface and also inhibited by 83% the ability of the cells to proliferate in response to anti-5'-NT antibodies and PMA. Thus, the activation signal provided by anti-5'-NT antibodies is apparently transduced, in large part, by a form of the enzyme that is attached to the membrane via glycosyl-phosphatidylinositol linkage. These data suggest that 5'-NT may play a role in lymphocyte activation as has been proposed for other glycosyl-phosphatidylinositol-anchored lymphocyte surface proteins.
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PMID:Antibodies to 5'-nucleotidase (CD73), a glycosyl-phosphatidylinositol-anchored protein, cause human peripheral blood T cells to proliferate. 255 May 43

In 18 horses there was no effect of age or sex on plasma activities of gamma-glutamyl transferase (gamma-GT), 5'-nucleotidase (5'-NT) and leucine aminopeptidase (LAP). All the enzymes were equally stable after storage for one month at -20 degrees C and there was no significant difference between their activities in serum and plasma in clinically normal horses. The pattern of release of gamma-GT, 5'-NT and LAP into plasma was studied in 114 horses which had a variety of orthopaedic, gastrointestinal, cardiovascular and hepatic (necrosis, lipidosis, neoplasia and cirrhosis) conditions. A definitive diagnosis of hepatic disease was established by histological examination of the liver. gamma-GT and 5'-NT were leaked into plasma in hepatic disease and gamma-GT was the more sensitive indicator of liver damage. There was some evidence that gamma-GT and 5'-NT plasma activities may increase in hepatic necrosis as well as in biliary obstruction. LAP was insensitive and not hepatic specific in the horse.
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PMID:Observations on gamma-glutamyl transferase, 5'-nucleotidase and leucine aminopeptidase activities in the plasma of the horse. 256 9

Plasma membrane-bound 5'-nucleotidase (5'-NT), gamma-glutamyltransferase (gamma-GT) and soluble deoxynucleotidyltransferase (TdT) were studied in peripheral blood cells (PBMN) of 35 individuals, 26 male and 9 female, with circulating anti-HIV antibodies. Twenty-six were drug abusers, 2 were drug abusers and homosexuals and 4 were homosexuals. Three did not fall into any risk group. The surface immunologic phenotype of cells stained with the fluorescent monoclonal antibodies Leu 5, Leu 3, Leu 2, Leu 12, Leu M3, Leu M1, anti-CALLA and anti-HLA-DR was delineated by flow cytometry. While the gamma-GT activity did not change, the lymphocyte 5'-NT activity was significantly less than normal in anti-HIV positive individuals and in anti-HIV negative drug abusers. TdT activity was detectable in 14 anti-HIV positive patients (40%), who did not have clinical AIDS. Of 8 patients with AIDS, 3 had a low level of TdT activity but 5 had cells completely devoid of TdT and 5'-NT activity. 5'-nucleotidase activity and the frequency of Leu 2 suppressor antigen bearing cells were the only independent variables that correlated with AIDS incidence.
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PMID:Enzymatic imbalance in peripheral blood mononuclear cells isolated from individuals with anti-HIV antibodies. 257 Jun 50


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