Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The subcellular distribution of 5'-nucleotidase and adenosine deaminase in rat brain hypothalamus and hippocampus was studied. In the hippocampus the 5'-nucleotidase activity was shown to be much higher than in the hypothalamus, while the adenosine deaminase activity, contrariwise, is nearly two times as high as that in the hypothalamus. During the analysis of subcellular distribution 5'-nucleotidase and adenosine deaminase were detected in all fractions under study, i. e., in nuclear, soluble, myelin fractions as well as in synaptic membranes, synaptosomes and "pure" mitochondria. The highest 5'-nucleotidase activity was found in the myelinic and synaptic fractions both in the hypothalamus and in the hippocampus. The highest adenosine deaminase activity was detected in the soluble fraction of the above structures. The enzyme activity in synaptic membranes and synaptosomes was nearly two times as low.
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PMID:[Subcellular distribution of adenosine system enzymes in the hypothalamus and hippocampus of the rat brain]. 198 48

Although several different enzymes with 5'-nucleotidase activity have been described in mammalian cells, their functions in nucleotide metabolism have not been clearly distinguished. In the present experiments, a mutant human T lymphoblastoid cell line (CEM-dAdoR) was selected specifically for resistance to deoxyadenosine toxicity. Compared to parental CEM cells, the variant had 4-fold elevated ATP-activated cytosolic 5'-nucleotidase activity. Other enzymes of potential importance for deoxyadenosine metabolism were indistinguishable in the two cell types. In medium supplemented with the adenosine deaminase inhibitor deoxycoformycin, the T cells with increased 5'-nucleotidase accumulated less nucleotides from exogenously added deoxyadenosine, or 9-beta-D-arabinofuranosyladenine, than did parental T lymphocytes. These metabolic changes were associated with resistance to the growth inhibitory effects of these nucleosides, and also to deoxyguanosine and to 9-beta-D-arabinofuranosylguanine. The T cells with elevated 5'-nucleotidase activity formed more 2',3'-dideoxyadenosine than did parental cells, in deoxycoformycin-supplemented medium. The accumulation of 2',3'-dideoxyadenosine 5'-triphosphate from 2',3'-dideoxyinosine was similarly augmented in the mutant. These data establish the importance of the cytosolic 5'-nucleotidase for the metabolism of purine 2'-deoxyribonucleosides, arabinonucleosides and 2',3'-dideoxyribonucleosides in T lymphoblasts.
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PMID:Deoxyadenosine-resistant human T lymphoblasts with elevated 5'-nucleotidase activity. 199 64

Blood serum activities of thymidine kinase, thymidine phosphorylase, adenosine deaminase, and 5'-nucleotidase were measured in normal women, women suffering from mastopathies and mammary carcinomas, aged 36 to 70. Blood serum activities of the studied enzymes in mammary carcinoma patients differed from these values in healthy women and those suffering from mastopathies; these differences were age-associated. Measurements of the time course of enzymic activities before and in the course of chemotherapy may be employed as a biochemical test to monitor therapy efficacy.
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PMID:[Use of the study of DNA metabolism enzyme activities as a test system in the treatment of breast cancer]. 205 30

The enzymatic pattern of five enzymes involved in the purine salvage pathway, namely purine nucleoside phosphorylase (EC 2.4.2.1), adenosine deaminase (EC 3.5.4.4), 5'-nucleotidase (EC 3.1.3.5), alkaline phosphatase (EC 3.1.3.1), and hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) has been evaluated both in human intestinal and breast carcinomas and compared to that of normal tissues. A higher level of hypoxanthine-guanine phosphoribosyltransferase was associated with tumor tissues. This metabolic alteration should lead to an elevated synthesis of nucleotides in cancer cells, might confer selective growth advantages to neoplastic tissues, and account, at least in part, for the difficulties encountered in the chemotherapy of human tumors, by using compounds affecting only the purine de novo biosynthesis.
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PMID:Purine salvage enzyme activities in normal and neoplastic human tissues. 212 39

Age-related changes in the activity of thymidine- and adenosine-metabolizing enzymes were studied in healthy females and those with breast cancer aged 46-70 years. A significant increase in activity of thymidine kinase, adenosine deaminase and 5'-nucleotidase and a decrease in that of thymidine phosphorylase were registered in blood serum of breast cancer patients of all age brackets. Adenosine deaminase activity in blood serum and lymphocytes of breast cancer patients was found to significantly change after surgery. A direct correlation was established between pretreatment thymidine phosphorylase activity and histological type of tumor, on the one hand and results of chemotherapy, on the other. The applicability of enzyme level assay for evaluating response to pre- and postoperative medication was studied.
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PMID:[Activity of the enzymes of DNA metabolism in the blood of patients with breast cancer]. 215 96

Influence of single (enzyme activities was determined 5h after the preparation) and multiple (for 7 days) DOCA administration on 5'-nucleotidase (EC 3.1.3.5) and adenosine deaminase (ES 3.5.4.4) activities in homogenate and subcellular fractions of the hypothalamus and hippocampus of the rat brain has been studied. It has been shown that DOCA enhances adenosine metabolism in the hypothalamus activating both the enzymes while in the hippocampus 5'-nucleotidase activity increases whereas adenosine deaminase activity decreases. Possible ways of mineralocorticoid effects on adenosine system and the role of this nucleoside in these hormones mechanism of action on CNS functional activity are being discussed.
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PMID:[Effects of desoxycorticosterone on 5-nucleotidase and adenosine deaminase activity in the hypothalamus and hippocampus of the rat brain]. 222 3

Activities of thymidine kinase, thymidine phosphorylase, adenosine deaminase and 5'-nucleotidase of AMP were studied in blood serum and lymphocytes of healthy women, patients with mastopathy and with mammary gland cancer of 23-70 years old. Age-dependent alterations in the enzymatic activity were detected in blood serum of healthy women. Activity of thymidine kinase was increased simultaneously with a decrease in thymidine phosphorylase activity in 36-70 years old oncological patients, while adenosine deaminase activity was increased in patients with mastopathy and with mammary gland cancer of all the age groups. Dynamics of the enzymatic activity studied before and during chemotherapeutic treatment may be used as one of biochemical tests for evaluation of the therapy efficiency in oncological patients.
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PMID:[Age-dependent characteristics of metabolism of DNA precursors in healthy women, patients with mastopathy and breast cancer]. 225 96

The activity of thymidine kinase, thymidine phosphorylase, adenosine deaminase, AMP 5'-nucleotidase was assessed in the serum of healthy females, patients with mastopathia cystica and those with stage IIIB breast cancer. The females age ranged from 23 to 70 years. The activity of the enzymes had significant differences in cancer patients. Minimal thymidine phosphorylase activity was found to suggest fibrous cancer. Changes in the enzymes levels in cancer patients on combined treatment may serve a biochemical test indicating the efficacy of the chemotherapy conducted.
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PMID:[Use of enzyme test in chemotherapy of patients with cancer of the breast]. 228 21

The influence of drugs improving sympathoadrenal system status on natural killer (NK) functional activity was studied in lung cancer patients. The activity of adenosine-metabolizing enzymes (adenosine deaminase and 5'-nucleotidase) in NK cells was found significantly altered, suggesting the involvement of this phenomenon in decreasing NK activity under tumor growth. Pharmacological correction of sympathoadrenal system status was followed by an increase in NK functional activity in lung cancer patients.
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PMID:[Increase of the functional activity of natural killers under the effects of the pharmacological correction of the sympathoadrenal system state in patients with lung cancer]. 230 58

The activities (Vmax) of several enzymes of purine nucleotide metabolism were assayed in premature and mature primary rat neuronal cultures and in whole rat brains. In the neuronal cultures, representing 90% pure neurons, maturation (up to 14 days in culture) resulted in an increase in the activities of guanine deaminase (guanase), purine-nucleoside phosphorylase (PNP), IMP 5'-nucleotidase, adenine phosphoribosyltransferase (APRT), and AMP deaminase, but in no change in the activities of hypoxanthine-guanine phosphoribosyltransferase (HGPRT), adenosine deaminase, adenosine kinase, and AMP 5'-nucleotidase. In whole brains in vivo, maturation (from 18 days of gestation to 14 days post partum) was associated with an increase in the activities of guanase, PNP, IMP 5'-nucleotidase, AMP deaminase, and HGPRT, a decrease in the activities of adenosine deaminase and IMP dehydrogenase, and no change in the activities of APRT, AMP 5'-nucleotidase, and adenosine kinase. The profound changes in purine metabolism, which occur with maturation of the neuronal cells in primary cultures in vitro and in whole brains in vivo, create an advantage for AMP degradation by deamination, rather than by dephosphorylation, and for guanine degradation to xanthine over its reutilization for synthesis of GMP. The physiological meaning of the maturational increase in these two ammonia-producing enzymes in the brain is not yet clear. The striking similarity in the alterations of enzyme activities in the two systems indicates that the primary culture system may serve as an appropriate model for the study of purine metabolism in brain.
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PMID:Developmental changes in the activity of enzymes of purine metabolism in rat neuronal cells in culture and in whole brain. 232 47


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