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)

Human thymuses, ranging in age from newborn to 62 years old, were studied enzyme histochemically. The thymic epithelial cells covering cortical surface and bordering vascular areas in the medulla were positive for 5'-nucleotidase, but not for other enzymes. The thymic epithelial cells composing Hassall's corpuscles were positive for acid phosphatase, esterases, beta-glucuronidase, and alkaline phosphatase, regardless of age, but totally negative for 5'-nucleotidase and ATPase. All enzymes examined except for beta-glucuronidase were demonstrated in some of the thymic epithelial cells scattered in the medulla, although the pattern of distribution and the degree of positivity were different by enzymes. These findings suggest that the thymic epithelial cells are composed of functionally heterogenous subpopulations. Acid phosphatase was demonstrated in thymocytes in both cortex and medulla, but 5'-nucleotidase and ATPase were observed in some thymocytes in the medulla of young thymus.
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PMID:Enzyme histochemical study on human thymus and its age change. 630 84

Lymphocyte populations of BALB/c mice were obtained from bone marrow, thymus, spleen, peripheral blood and lymphoid nodes. Subpopulations of thymocytes and bone marrow T-lymphocyte precursors were separated by density gradient centrifugation. The activity of adenosine deaminase (ADA) undergoes a marked increase during the evolution of bone marrow T-cell precursors to immature thymocytes, and a decrease with thymocytes maturation. The peripheral blood lymphocytes (PBL) present the lower activity of the enzyme, and lymphocytes from spleen (SL) and lymphoid nodes (LNL) show activity in the order of that in mature thymocytes. The activity of purine nucleotide phosphorylase (PNP) in the different lymphocytes populations experiments a very little variation with the T-lymphocyte differentiation. With the evolution of T-lymphocyte precursors to immature thymocytes the 5'-nucleotidase (5'-NT) activity experiment a 2-fold decrease. The thymocytes maturation is correlated with an increase in the activity of 5'-NT. The PBL present the maximal activity of the enzyme, whereas in spleen and LNL its levels of activity are in the range of that in mature thymocytes and bone marrow T-cell precursors respectively.
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PMID:The distribution of adenosine deaminase, purine nucleotide phosphorylase and 5'-nucleotidase in subpopulations of thymocytes, bone marrow cells and other lymphoid organs in mice. 632 33

The activities of adenosine deaminase, purine nucleoside phosphorylase, membrane 5'-nucleotidase and DNA content in thymus and spleen lymphocytes as well as the immune function of T and B lymphocytes of the spleen of C3HA mice with o-AAT-induced hepatomas were studied 1, 3 weeks and 3, 8, 12 months after o-AAT treatment was instituted. In the early stages of the hepatocarcinogenesis (up to 3 months), the elevation of the activity of all the enzymes and DNA content in thymocytes and T and B lymphocytes was observed. These changes coincided with the enhancement of the immune responses that manifested in the increased content of PFC, EA-RFC and high response to PHA and Con A. In the late stages, the decreased activities of purine nucleosides and nucleotide metabolizing enzymes correlated with disturbances of lymphocyte differentiation and lowering of the host immune response.
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PMID:[Changes in purine metabolism and in the immune response in the thymic and splenic lymphocytes of C3HA mice during chemical hepatocarcinogenesis]. 633 63

In the present report the characteristics of nonepithelial phagocytic cells of the murine thymic reticulum are described. Primary cultures were established from thymic fragments. Nonadherent cells with hairy membranes proliferated on the surface of established primary monolayers. These cells were recovered and replated in secondary cultures were they appeared as large adherent cells with dendritic shape. At the electron microscopic level, phagocytic cells of the thymic reticulum in culture (P-TR-C) appear as clear vacuolated cells with an indented nucleus and few lysosomes; this morphological aspect makes them different from the common macrophage, despite their phagocytic capacity. P-TR-C are positive for nonspecific esterase, acid phosphatase which is found in the few lysosomes present, 5'-nucleotidase and alpha-D-mannosidase, but negative for peroxidase. A high proportion of alpha-mannosidase-positive cells is inconsistent with the common macrophage, but in common with other cells with dendritic shape such as Langerhans cells. They are Thy-1-, Ig- and nearly half of them are IA+. P-TR-C can be defined as the stimulator cells for syngeneic stimulation; they are able to induce the proliferation of lymphocytes enriched in mature syngeneic medullary thymocytes, but not in immature cortical ones. Characteristics of P-TR-C make them very similar to the interdigitating cells described in the peripheral lymphoid organs and in the thymus in situ.
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PMID:Thymic reticulum in mice. II. Culture and characterization of nonepithelial phagocytic cells of the thymic reticulum: their role in the syngeneic stimulation of thymic medullary lymphocytes. 660 Oct 9

The time-course of the ultrastructural changes and activities of 6 marker enzymes of subcellular particles (succinate dehydrogenase, beta-glucosidase, beta-N-acetylglucosaminidase, acid RNAse, glucose-6-phosphatase and 5'-nucleotidase) has been studied in the liver, spleen and thymus in rats administered T-2 toxin (mycotoxin produced by some Fusarium species). A pronounced difference in the effect of T-2 toxin on the organs has been found. In the liver, the toxin induced a destruction of rough endoplasmic reticulum membranes, reduced ribosome number and progressively decreased activities of most enzymes. In the spleen, early and significant ultrastructural disturbances of all the cell membrane components and simultaneous lysosomal activation were observed. The changes in the thymus were characterized by a fast development of cell hydratation, organelle swelling and necrosis of some thymocytes with parallel increase in repair processes, infiltration by phagocytes and a selective activation of lysosomal hydrolases in the end of experimental time (72 h.). The results obtained emphasize an importance of cellular and subcellular membrane alterations in the mechanism of T-2 toxin action.
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PMID:[Effect of T-2 toxin on organ ultrastructure and organelle-specific enzyme activity in rats]. 665 69

Different human T cell populations were assayed for susceptibility of DNA synthesis to inhibition by deoxyguanosine. T lymphocytes from the thymus were most sensitive to inhibition of proliferation by deoxyguanosine (90% inhibition at 10 microM deoxyguanosine). This exquisite sensitivity of thymocytes appeared related to an enhanced ability of these cells for uptake and phosphorylation of deoxyguanosine to deoxyGTP and by their reduced ability to degrade accumulated deoxyGTP. Compared to more mature T lymphocytes and B cells, thymocytes contained the highest level of the salvage enzyme deoxynucleoside kinase and the lowest level of the nucleotide degrading enzyme, 5'-nucleotidase. The present study suggests that the levels of these 2 enzymes can serve as differentiation markers, identifying T cells at various stages of maturation, and that the loss of sensitivity to deoxyguanosine toxicity may be a stepwise process. Further, a deficiency in purine nucleoside phosphorylase may preferentially interfere with T cell maturation at an intrathymic stage of T cell differentiation.
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PMID:The expression of deoxyguanosine toxicity in T lymphocytes at different stages of maturation. 696 9

A number of cell surface markers (T200, ThB, Thy1, Lyt1 and Lyt2 and a glycolipid) and enzymes (ATP-ase, acid phosphatase, beta-glucuronidase, 5'-nucleotidase, non-specific esterase, ANAE and chloroacetate esterase) were determined for two murine T-cell lymphomas: the DBA/2-strain-derived SL2 with a phenotype close to that of a mature thymocyte and the GRS-strain-derived GSRL13 with a phenotype of a more primitive thymocyte. While the pattern of expression of the enzymes was similar for SL2 and GRSL13 and as such indistinguishable from that of the majority of thymus cells, the pattern of cell surface antigen expression was clearly different. GRSL12 cells express the ThB antigen and a glycolipid antigen detectable with monoclonal antibody 30-H11, but not Lyt1 and Lyt2 antigens. SL2 cells, however, do not express ThB and the glycolipid antigen, but do express Lyt1 and Lyt2.
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PMID:Cell surface antigen phenotypes and enzyme expression patterns of two murine T-cell lymphomas derived from early and/or mature thymus cells. 698 39

The cytosolic 5'-nucleotidase specific for IMP, GMP, and their deoxyderivatives has been purified approximately 1000 times from calf thymus. The enzyme, in the presence of a suitable nucleoside, can act as a phosphotransferase, catalyzing the transfer of the phosphate moiety from a nucleoside monophosphate donor to a nucleoside acceptor, thus operating as an interconverting activity. This phosphorylating activity has drawn the attention of several research groups because the cytosolic 5'-nucleotidase represents the only cellular enzyme able to phosphorylate inosine and guanosine analogs, which are not substrates of known cellular nucleoside kinases. In this paper, we report the kinetic parameters of the bifunctional enzyme and its response to variations in adenylate energy charge. The results seem to indicate that in the presence of physiological concentrations of ATP and phosphate, the enzyme behaves mainly as a phosphotransferase, its activity being dependent only on the availability of a suitable nucleoside.
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PMID:The bifunctional cytosolic 5'-nucleotidase: regulation of the phosphotransferase and nucleotidase activities. 803 Nov 49

Cytosolic 5'-nucleotidase/nucleoside phosphotransferase has been purified from calf thymus. Since the same protein is able to catalyze both the hydrolysis and the interconversion of several nucleoside monophosphates, it is necessary to study the effect of different metabolites and assay conditions on both activities in order to elucidate their physiological roles. We describe herein a method which allowed us to follow both activities contemporaneously in the same assay mixture. The method takes advantage of the observation that deoxyGMP is both a good substrate for hydrolysis and a good phosphate donor for the phosphotransferase reaction, but its dephosphorylated product, deoxyguanosine, is not a phosphate acceptor. As a consequence, it is possible to follow both the deoxyguanosine production and the transfer of phosphate from deoxyGMP to the best phosphate acceptor, inosine, during the reaction, applying a method for the chromatographic separation on HPLC of both substrates (inosine and deoxyGMP) and both products (IMP and deoxyguanosine). The method was applied to the determination of the KM for inosine.
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PMID:Cytosolic 5'-nucleotidase/nucleoside phosphotransferase: a single assay for a bifunctional enzyme. 830 94

Activity of 5'-nucleotidase was inhibited in thymus tissue of tumor-bearing mice; bradykinin (1 mg/kg body weight) increased the enzymatic activity 2.0-2.2-fold. Administration of bradykinin led to inhibition of allogenic Crocker's sarcoma growth and to stimulation of syngeneic mastocytoma P-815 growth, which was inoculated into noninbred and BALB/c mice, respectively. Hence, bradykinin activated 5'-nucleotidase in Crocker's sarcoma and did not affect the enzymatic activity in tumor P-815. This suggests that activity of 5'-nucleotidase is of importance in evaluation of the thymus tissue state as well as it demonstrates the tumoral tissue sensitivity to bradykinin.
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PMID:[Activity of 5'-nucleotidase from thymus and tumors upon administering bradykinin to tumor-bearing mice]. 851 76


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