Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An analog of lysophosphatidylcholine (1-dodecyl-propanediol-3-phosphocholine) which does not impair membrane-bound enzymes was used for the induction of shedding of membrane vesicles from intact calf thymocytes. Without liberation of intracellular enzymes such as lactate dehydrogenase (EC 1.1.1.27) the shedded membranes contained 15--25% of the total activity of the plasma membrane enzymes alkaline phosphatase (EC 3.1.3.1), nucleotide pyrophosphatase (EC 3.1.4.1) and gamma-glutamyl transferase (EC 2.3.2.2). Membrane-free supernatants only exhibited trace activities of these enzymes. Without further purification, the specific enzyme activities in shedded membranes were of the same order of magnitude as in purified plasma membranes prepared after nitrogen cavitation of thymocytes. Small amounts of membrane vesicles which showed a different composition could be removed without detergent. These membranes exhibited a 3-fold lower specific activity of the gamma-glutamyl transferase while that of the alkaline phosphatase and nucleotide pyrophosphatase was similar as in detergent induced membrane vesicles. Distinct differences also were found in the protein pattern. The content of total cholesterol and phospholipid in vesicles shed spontaneously or after detergent treatment was nearly identical, however, significant differences were found in the fatty acid composition of the main phospholipids. The content of polyunsaturated fatty acids (linoleic and arachidonic acid) increased in the order: spontaneously shedded membranes, detergent induced vesicles, conventional purified plasma membranes. These results are discussed in terms of the heterogeneous composition of areas of the thymocyte plasma membrane.
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PMID:Spontaneous and detergent-induced vesiculation of thymocyte plasma membranes. 624 81

Intact polymorphonuclear neutrophils were modified chemically by a poorly permeable reagent, diazotized sulfanilic acid, and the changes in the activity of 5'-nucleotidase, alkaline phosphodiesterase, and leucine aminopeptidase were examined. Among three plasma membrane enzymes, 5'-nucleotidase activity was hardly detected in the human neutrophils. The activity of alkaline phosphodiesterase was observed in all the neutrophils examined, but was not inhibited by diazotized sulfanilic acid in the guinea-pig neutrophils. On the other hand, the activity of leucine aminopeptidase was not only found but also inhibited by diazotized sulfanilic acid without the inhibition of lactate dehydrogenase, a cytosol enzyme, in all the neutrophils, suggesting that leucine aminopeptidase is located generally on the plasma membrane as an ecto-enzyme in the neutrophils.
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PMID:Leucine aminopeptidase as an echo-enzyme of polymorphonuclear neutrophils. 625 75

Experimental blisters were produced with suction on normal human skin and simultaneously on skin inflamed after exposure to middle wave ultraviolet light. Total proteins and marker enzymes for the plasma membrane, cytosol, lysosomes, peroxisomes, mitochondria, and microsomes were assayed in the blister fluid. In blisters on erythematous skin, a large increase of lactate dehydrogenase from cytosol was noted. A small increase of the plasma membrane marker phosphodiesterase I and some increase of alpha-mannosidase from lysosomes was found. No significant increase in total proteins or in microsomal marker enzymes were not detectable. It is concluded that cutaneous cells to some extent may lose intracellular enzymes without visible signs of irreversible damage (necrosis), but that an UVB-induced injury/regeneration cycle probably explains the enzyme release.
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PMID:Release from intracellular enzymes from cutaneous cells after non-necrotizing damage by ultraviolet light. 626 41

5'-nucleotide phosphodiesterase isozyme-V (5'-NPD-V) was evaluated in 85 biopsy proven breast cancer patients as a potential marker for early liver metastasis. It correctly predicts liver metastasis in 6/7 (85.7%) patients with abnormal radiologic liver scan and 2/2 other patients with palpable liver. Serum glutamic-oxaloacetic transaminase (SGOT), lactic dehydrogenase (LDH), alkaline phosphatase (AP) and total bilirubin (B) were also determined in 79 of these patients as routine liver function tests (LFT). Forty-one out of 79 from this group had all four markers all within normal limits. Yet of the 41 patients, 12 patients were found positive for 5'-NPD-V. Of these 12, one was found to have liver metastasis at surgery and one had abnormal liver scan. Five other patients had liver dysfunction and one had been diagnosed as an alcoholic. Four others had no evidence of either liver problems or liver metastasis, but follow-up data were lacking. This retrospective study, therefore suggests that there is a definite advantage to include the 5'-NPD-V in the liver profile studies for breast cancer patients, although a positive 5'-NPD-V may only indicate liver repair or liver regeneration. Long-term prospective studies of these tests with breast cancer patients should be worthwhile. No relation was found between 5'-NPV-V and axillary lymph node involvement or the estrogen receptor status of the excised tumor. Thus there is no evidence currently that the appearance of the 5'-NPD-V in serum is related to lymph node metastases or hormonal control.
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PMID:Evaluation of 5'-nucleotide phosphodiesterase isozyme-V as a predictor for liver metastasis in breast cancer patients. 628 35

A continuous spectrophotometric assay for cAMP phosphodiesterase has been optimized and adopted for assaying calmodulin in biological samples. This method utilizes the coupled enzyme reactions of myokinase, pyruvate kinase, and lactic acid dehydrogenase. The effective molar extinction coefficient for this method is 1.25 X 10(4) at 340 nm. A point-assay method capable of handling a large number of samples has also been established. This same procedure can also be adopted for the assay of calcineurin and other calmodulin-binding proteins.
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PMID:An optimized continuous assay for cAMP phosphodiesterase and calmodulin. 632 36

We have investigated the potential role of adenosine 3',5'-cyclic monophosphate (cAMP) in controlling levels of enzymes of energy metabolism in primary cultures of rat skeletal muscle cells. Incubating myotubes with cholera toxin or forskolin (2 persistent activators of adenylate cyclase) significantly increased the levels of two enzymes of oxidative metabolism, fumarase and malate dehydrogenase. These enzymes were also increased (1.5- to 2.0-fold) by phosphodiesterase inhibitors (caffeine, theophylline, theobromine, 3-isobutyl-1-methylxanthine, papaverine, MJ 1988, Ro 20-1724, or SQ 20009) and the cAMP derivatives: 8-bromo-cAMP or dibutyryl cAMP. In contrast two enzymes of glycolytic metabolism, lactate dehydrogenase and pyruvate kinase, were not consistently affected by these agents. The results presented provide strong evidence that an increase in cAMP can lead to an increase in certain enzymes of oxidative energy metabolism.
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PMID:Evidence that levels of malate dehydrogenase and fumarase are increased by cAMP in rat myotubes. 633 Nov 85

It has been shown that low concentrations of E. coli lipopolysaccharides (LPS) greatly and selectively stimulate phagocytosis and related functions in mouse bone marrow-derived macrophages. Culture in the presence of 50 ng/ml LPS induced on average a 10-fold enhancement of phagocytosis of IgG-coated sheep erythrocytes. Activation was in two stages--a small increase observed during the first 8 to 12 hr, and the major increase noted between 16 and 24 hr. Phagocytic activity remained at the maximal level for 24 hr and then declined progressively. Stimulation by LPS was dose-dependent; significant effects could be observed at 0.8 ng/ml and the maximum was reached at 10 ng/ml. LPS-treated cells also showed a markedly increased tendency to form colonies. All these effects could be prevented by the addition of 100 ng/ml polymyxin B together with LPS, indicating that the active principle is lipid A. The LPS-dependent increase in phagocytic activity is probably mediated by increased Fc receptor capacity because both parameters were influenced in parallel by the stimulus. Phagocytosis-related events, such as enhanced hexose monophosphate shunt activity, H2O2 formation, and nitroblue tetrazolium reduction were also stimulated by LPS. By contrast, pinocytosis was unaffected. Measurements of cell-associated enzyme activities showed that lactate dehydrogenase, acid phosphatase, and cathepsin D were significantly increased. Beta-glucuronidase, beta-galactosidase, alkaline phosphodiesterase, and aminopeptidase were unchanged and NAD nucleosidase was markedly decreased after LPS treatment. 5'-Nucleotidase and glucosamine uptake were undetectable both in control and LPS-stimulated cells. LPS treatment induced a significant increase in cell-associated protein, but did not result in cell proliferation or increased cell loss as shown by the DNA content that remained constant. LPS-induced changes were dependent on de novo protein synthesis; cycloheximide prevented enhancement of phagocytosis, Fc receptor capacity, and colony formation.
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PMID:Stimulation of phagocytosis in bone marrow-derived mouse macrophages by bacterial lipopolysaccharide: correlation with biochemical and functional parameters. 673 51

Human peripheral blood mononuclear leucocytes (PBML) stimulated with concanavalin A (Con A) or phytohaemagglutinin (PHA) produced a soluble factor which inhibits lung fibroblast DNA synthesis and growth. Lymphocyte enriched preparations produced significant growth inhibitory activity in the presence of PHA whereas media from adherent mononuclear cells incubated in the presence of the mitogen did not contain similar activity. This fibroblast growth inhibitory factor (FGIF) was non-dialysable, heat stable and resistant to pH 5. FGIF was also resistant to treatment with chymotrypsin and phosphodiesterase but partially sensitive to treatment with trypsin. Interestingly, there was significant suppression of FGIF production by PBML cultured with PHA in the presence of low concentrations of chrysotile asbestos (5-25 micrograms/ml). In this regard, asbestos (25 micrograms/ml) was not cytotoxic for lymphocytes but had a damaging effect on monocytes as evidenced by the release of lactate dehydrogenase (LDH) a cytoplasmic enzyme, in their culture media. These findings indicate that stimulated lymphocytes have the ability to inhibit fibroblast proliferation by releasing FGIF and that asbestos interfere with this process. Thus, while FGIF may regulate the extent of connective tissue proliferation during normal repair process, suppression of its production by asbestos may contribute to excessive fibroblast accumulation and fibrosis.
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PMID:In vitro suppression of fibroblast growth inhibitory lymphokine production by asbestos. 687 28

The protein concentration in bile from several species is reported. The changes in output of protein, bile salts and several enzymes have been followed in rat bile over a 48 h cannulation period. Bile-salt concentration dropped rapidly owing to interruption of the enterohepatic circulation but the output of protein, lysosomal enzymes [acid phosphatase (EC 3.1.3.2) and beta-D-glucuronidase (EC 3.2.1.31)] and plasma-membrane enzymes [5'-nucleotidase (EC 3.1.3.5) and phosphodiesterase I (EC 3.1.4.1)] was maintained. Liver cell damage, monitored by output of lactate dehydrogenase, was very low throughout. Protein, lysosomal enzymes and plasma-membrane enzymes showed different patterns of output with time, but all showed a net increase between 12 and 24 h. The output of lysosomal and plasma-membrane enzymes was between 1 and 5% of the total liver complement over the first 24 h; if inhibition by biliary components is taken into account the output of some of these enzymes, particularly acid phosphatase, may be greater. Ultracentrifugation of bile showed that as the concentration of bile salts decreases the proportion of plasma-membrane enzymes in a sedimentable form increases. The results are discussed in relation to other studies of biliary proteins and to studies of the perturbation of membranes and cells with bile salts.
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PMID:Enzymes and proteins in bile. Variations in output in rat cannula bile during and after depletion of the bile-salt pool. 730 64

Current cell disruption and fractionation techniques are time consuming and unsuitable for metabolic studies. We have developed a rapid method for platelets in which separation of cytosol and particle fraction is obtained within 50 s. Isolated platelet suspensions were incubated with low concentrations of digitonin followed by separation of soluble and particle fraction by centrifugation through a phthalate layer. Cell disruption was 90.1+/-4.2% (mean+/-SD, n=18; lactate dehydrogenase leakage). Contamination of granules: acid hydrolase vesicles 16.2+/-3.6% (n=18, beta-N-acetylglucosaminidase), dense granules 7--9% (n=3, 14C-serotonin), mitochondrial matrix 0.6+/-0.1% (n=18, glutamate dehydrogenase). Low concentrations of digitonin did not affect sialic acid content, nucleoside diphosphate kinase and phosphodiesterase activity in isolated membranes. The method showed that most enzymes of glycolysis and hexose monophosphate shunt were localized in the cytosol except for hexokinase (96% particle bound), phosphoglucose isomerase (10% bound) and glutathion reductase (26% bound). About half the total ATP+ADP and most glycolytic intermediates were found partly particle bound, especially fructose 1,6-diphosphate (40% bound). The data suggest that in platelets glycolysis occurs in different cell compartments.
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PMID:Rapid separation of cytosol and particle fraction of human platelets by digitonin-induced cell damage. 737 1


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