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)

Low activity of 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, EC 3.1.3.5) in T lymphoblasts may explain the marked sensitivity of this cell to deoxynucleotide accumulation when compared to B lymphoblasts. The relevance of such observations with cultured cells to the normal immune system requires the demonstration of similar differences in the 5'-nucleotidase activity of normal human lymphocyte subpopulations. Sheep erythrocyte (E) rosette-forming cells from normal thymus, tonsil, and peripheral mononuclear cells have 5'-nucleotidase activities of 1.7, 11.3, and 21.2 nmol/hr per 10(6) cells. Non-E-rosette forming cells from the peripheral blood or tonsil have 5'-nucleotidase activity comparable to the higher levels found in the peripheral E-RFC. Increased levels of 5'-nucleotidase activity may be a marker for post-thymic T lymphocytes. T lymphoblasts have 5'-nucleotidase activity similar to values demonstrated for E-RFC in thymus, whereas cultured B lymphoblasts have 5'-nucleotidase activity 15 times greater than that of T lymphoblasts. On the basis of these observations, the 5'-nucleotidase deficiency in congenital agammaglobulinemia has been reevaluated. In these patients the data indicate that peripheral E-rosette forming cells have the enzyme deficiency, demonstrating an abnormality of T lymphocytes in this disorder of immunoglobulin production.
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PMID:Distribution of 5'-nucleotidase in human lymphoid tissues. 31 65

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