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

The influence of a new antitumor enzyme L-lysine alpha-oxidase on Lewis lung carcinoma spreading was studied in mice in which primary tumor had been removed. The enzyme was found to significantly decrease the extent and number of lung metastases as compared to mice which hadn't received L-lysine alpha-oxidase. This was matched by recovery of alveolar macrophages functional activity, as assessed by adenosine deaminase and 5' nucleotidase levels in these cells. Moreover, antimetastatic and cytostatic effect was confirmed by the measuring of polyamine concentration in mice erythrocytes.
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PMID:[Antimetastatic effect of L-lysine-alpha oxidase]. 237 55

Thymosin fraction 5 (Thymosin) has numerous immunoregulatory activities including modulation of enzymes involved in lymphocyte maturation. The effect of Thymosin on the purine metabolic enzymes adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5' nucleotidase (5'NT) in null and T-enriched peripheral blood lymphocytes from sexually active asymptomatic homosexual males (AS), patients with the AIDS-related symptom complex (ARC), and those with acquired immune deficiency syndrome (AIDS) was examined and compared to its effect on lymphocytes from healthy heterosexual controls. Mean ADA activity was significantly higher in null cells from fourteen AIDS patients than in five asymptomatic homosexuals, ten ARC patients, or 27 controls. Mean PNP activity was significantly elevated in null-enriched lymphocytes from ten ARC and fourteen AIDS patients compared to controls. No differences in these enzymes were found in T-enriched cells from any group. 5'NT was markedly decreased in both null and T lymphocytes in all homosexual groups relative to controls. Homosexuals had significantly elevated percentages of OKT10 positive and Ia positive lymphocytes compared to controls. Thymosin at an optimal concentration of 150 micrograms/ml caused significant decreases in mean ADA and PNP activity in null lymphocytes from ARC + AIDS patients along with a significant decrease in the percentage of OKT10 positive lymphocytes. No phenotypic changes were seen in AS or control lymphocytes. The data suggest that Thymosin has a maturational effect in vitro on immature T cells from symptomatic homosexuals.
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PMID:In vitro modulation of purine enzyme metabolism and lymphocyte surface marker expression by thymosin fraction 5 in homosexual males. 299 64

The loss of the catabolic products of adenosine triphosphate in the form of purine nucleosides and oxypurines during ischemia and subsequent reperfusion may limit adenine nucleotide regeneration. This study compared the effects of infusion of inhibitors of the major reactions involved in the degradation of adenosine triphosphate to inosine on the postischemic recovery of high energy phosphate and myocardial function. Inhibitors of adenylate kinase, 5'nucleotidase, adenosine translocase and adenosine deaminase were studied. Following 30 minutes of ischemia, only hearts infused with alpha, beta, methylene adenosine diphosphate (5' nucleotidase inhibitor) recovered significantly better ventricular function than control (p less than 0.05), but all hearts had increased adenosine triphosphate regeneration (p less than 0.05). The formation and washout of greater than 30% of the total adenine pool metabolites was not prevented by any drug. Nevertheless all manipulations of adenine metabolism resulted in recruitment of high energy phosphate during preischemic infusion.
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PMID:The influence of inhibitors of the ATP degradative pathway on recovery of function and high energy phosphate after transient ischemia in the rat heart. 302 47

Attempts to identify mechanisms by which calcium antagonists might influence intracellular metabolism have not yet yielded conclusive findings. In this study bepridil, verapamil, nifedipine, and nisoldipine were found to have no influence on the rate of rat heart myosin adenosine triphosphatase or the calcium dependence of myofibrillar adenosine triphosphatase. None of these calcium antagonists alters the rate of reaction of any of the adenine nucleotide catabolic or adenosine salvage enzymes, adenylate kinase, creatine kinase, adenosine kinase, adenosine deaminase, or 5' nucleotidase, in extracts of rat heart. All four compounds, however, reduced, apparently in a non-specific manner, the rate of uptake of adenosine by myocytes isolated from rat heart. It is concluded that calcium antagonists may, through intercalation with the sarcolemmal membrane, inhibit efflux of adenosine formed by catabolism of adenine nucleotides in ischaemic myocytes. This might offer therapeutic advantage since the intracellular concentration of adenosine would thereby be increased, allowing an increased rate of incorporation of adenosine into the adenosine triphosphate pool in reoxygenated myocardium.
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PMID:Calcium antagonists and adenine nucleotide metabolism in rat heart. 349 85

Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed by immunofluorescence analysis of thymic tissue from SCID foals. Those cells present were larger than normal cortical thymocytes. Furthermore, their activities of adenosine deaminase, adenosine monophosphate-deaminase, and 5' nucleotidase differed from those of normal cortical thymocytes. The combined evidence of monoclonal antibody analysis, size parameters, and purine enzyme activities demonstrate the near absence of cortical thymocytes in horses with this genetically defined immunodeficiency disorder.
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PMID:Defective thymocyte maturation in horses with severe combined immunodeficiency. 350 Sep 80

1. Hydrolyzing activities on cAMP were investigated in E. coli B cells incubated in the presence or absence of 10(-5) M spermine, spermidine or putrescine. 2. Bacterial cells incubated in the presence of each of the investigated polyamines show an increase in the PDE (phosphodiesterase) activities already evident after 3 min of incubation, reaching the maximum between 5 and 10 min. disappearing between 15 and 25 min. 3. The stimulating effect is higher in the presence of lower (10(-6) M) substrate concentration (high affinity PDE activities). 4. Kinetic analyses carried out for the "high affinity" PDE activity, indicate that spermidine and putrescine are the most effective on increasing both the Vmax or the apparent Km. 5. Kinetic analysis carried out for the "low affinity" PDE activity, indicate that putrescine is the most active on increasing either the Vmax or the apparent Km and that spermine and spermidine have both quantitatively and qualitatively comparable effects. 6. Analyses, by TLC, of the products of the hydrolytic activities on cyclic AMP (5'-adenosine monophosphate (5'-AMP), adenosine, inosine) indicate that the incubation in the presence of each of three polyamines, results in an increase also of the 5' nucleotidase and adenosine deaminase activity.
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PMID:Hydrolyzing activities on cAMP in E. coli B cells incubated in the presence of polyamines. 627 51

Expression of the enzyme terminal deoxynucleotidyl transferase (TdT) was studied in human thymus during ontogeny and development. In five fetal thymus samples, the enzyme activity was barely detectable. At birth, the terminal transferase activity remained low. Maximum expression of the enzyme activity occurred between 10 and 40 mo of age. Analysis of six other enzyme activities, adenosine kinase, deoxyadenosine kinase, AMP deaminase, dAMP deaminase, 5' nucleotidase, and adenosine deaminase confirmed the normal status of the thymic tissue. A careful analysis of thymic architecture revealed that involution did not occur as a result of the disease process that necessitated cardiac surgery. By immunofluorescence, the TdT antigen was localized exclusively in the nucleus of cortical thymocytes. Protein immunoblotting studies indicated that human thymic terminal transferase exists as a single high m.w. species in individuals under 30 mo of age. Thereafter, a variant m.w. species is detectable. The increase in expression of this enzyme coincides with the increase observed in serum immunoglobulin levels during maturation and precedes the maximum development of the human thymus.
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PMID:Expression of terminal deoxynucleotidyl transferase in human thymus during ontogeny and development. 640 69

cAMP is commonly measured using either immunoassay or high-performance liquid chromatography. The current methods are sensitive but may lack versatility and be expensive; also, radioactivity is potentially harmful to the operator and environment. Given these concerns, we developed a highly sensitive enzymatic fluorometric assay for cAMP. The method consists of five steps: (1) destruction of interfering compounds with apyrase, 5' nucleotidase, adenosine deaminase, and alkaline phosphatase; (2) conversion of cAMP to AMP; (3) conversion of AMP to ATP; (4) amplification of ATP by ATP-ADP cycling; and (5) fluorometric measurement of resultant NADPH. cAMP was measured in male Sprague Dawley rats anesthetized with pentobarbital. Stimulated rats (n = 4) received isoproterenol (16 micrograms/kg, s.q.) and aminophylline (20 mg/kg, s.q.), whereas controls (n = 4) received no additional drug. With the enzymatic fluorometric assay, cAMP content in heart, liver, and kidney (pmol/mg wet wt, mean +/- SEM) was 0.34 +/- 0.03, 0.33 +/- 0.03, and 0.92 +/- 0.11 in the control group and 0.77 +/- 0.10, 0.66 +/- 0.04, and 1.53 +/- 0.12 in the stimulated group, respectively. The total assay duration including sample reading procedure varied at 4.5-9.5 hr, depending on its sensitivity. cAMP from the same samples was measured using a commercially available enzyme immunoassay kit and was found to be very similar to the enzymatic fluorometric assay. We conclude that this new assay is sensitive, safe, versatile, and inexpensive and can be used to measure cAMP in multiple types of tissue, including biopsy samples weighing < 200 micrograms.
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PMID:Enzymatic fluorometric assay for tissue cAMP. 786 85

We determined activities of adenosine deaminase (ADA), 5' nucleotidase (5NT), xanthine oxidase (XO), superoxide dismutase (Cu-Zn SOD), and catalase (CAT) enzymes in 15 human laryngeal tissues with well-differentiated squamous cell carcinomas, in 15 corresponding tumor-free adjacent tissues and in 7 normal laryngeal tissues. We found lower ADA and 5NT and higher XO, Cu-Zn SOD, and CAT activities in cancerous tissues than those in corresponding noncancerous ones. In the correlation analysis, we established one positive intercorrelation, which was between ADA activities of tumor tissues and noncancerous adjacent tissues. We also found some significant intracorrelations between enzyme activities of the tissues, all of which were positive in cancerous ones.
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PMID:Adenosine deaminase, 5' nucleotidase, xanthine oxidase, superoxide dismutase, and catalase activities in cancerous and noncancerous human laryngeal tissues. 813 95

Hepatocytes are affected by many cytokines and growth factors during liver regeneration. In regenerating rat liver cells cultures, liver cell growth factor (LCGF), hepatic stimulator substance (HSS), interleukin-1 beta (IL-1 beta), as well as their combination, were tested for their ability to activate the enzymes involved in purine metabolism. The enzymes tested were 5' nucleotidase, AMP deaminase, adenosine deaminase and xanthine oxidase. The cytokines alone or in combination, activated 5' nucleotidase and adenosine deaminase. Activity of AMP deaminase was stimulated by IL-1 beta associated with LCGF, HSS and IL-1 beta. Xanthine oxidase was stimulated by IL-1 beta but not with HSS and LCGF. Associated with IL-1 beta these two substances decreased its activity. A novel approach to the understanding of the mechanisms involved in the regulation of purine metabolism during liver regeneration, is proposed.
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PMID:Effects of growth factors on the enzymes of purine metabolism in culture of regenerating rat liver cells. 869 4


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