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At least 793 records · Page 44Linked to original sources
PubMed1990

[Synaptic localization of 5'-nucleotidase activity in the cerebellar cortex in adult rats irradiated by X rays after birth].

5'-nucleotidase cytochemistry was performed in the cerebellum of adult rats exposed previously to a single postnatal X-irradiation which maintains until adulthood the normally transient multiple innervation of cerebellar Purkinje cells by climbing fibers. 5'-nucleotidase activity persists in climbing fiber synapses and other asymmetrical synapses while it is transient during normal development. Therefore, in the X-irradiated rat, an immature stage of the excitatory synapses persists which, for the climbing fibers, coïncides with or precedes their involution during normal development.

5'-Nucleotidase↗
PubMedDate not supplied

[Increase in 5'-nucleotidase and decrease in guanylate kinase activity in the brain and liver of irradiated rats].

The activity of 5-nucleotidase (EC 3.1.3.5) and guanylate kinase (EC 2.7.4.8) in the mitochondria and supernatant of the brain and liver was determined in experiments on Wistar male rats 1, 3, 6, 24 and 48 h after the single total irradiation by gamma-quanta in a dose of 30 Gy. It is established that the activity of 5-nucleotidase in the liver endures phase changes with the predominance of the enzyme activation; in the brain it is higher during the whole period of investigation. The guanylate kinase activity lowers in the both fractions of the organs under study during the whole period of the experiment.

5'-Nucleotidase↗
PubMed1990

[Effects of desoxycorticosterone on 5-nucleotidase and adenosine deaminase activity in the hypothalamus and hippocampus of the rat brain].

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.

5'-Nucleotidase↗
PubMedDate not supplied

[Kinetic properties of 5'-nucleotidase in the adipose tissue, liver and blood of rats of different ages].

The kinetic characteristics (Vmax and Km) of membrane-bound and serum 5'-nucleotidases from rats of different age groups are studied. The age-related increase of Km parameter in plasma membranes of fatty tissue and liver demonstrated a lower enzyme affinity to the substrate in ageing membranes. The specific activity of 5'-nucleotidase in blood serum of aged animals was below that in young ones, while Km value remained stable. Tissue differentiation of the catalytic properties of the enzyme and their aged-related characteristics may be to a considerable extent determined by the physicochemical state of cell membranes.

5'-Nucleotidase↗
PubMed1975

[Semiautomatic method of measurement of serum 5'nucleotidase activity].

A semi-automated method for determining the 5'-nucleotidase activity in human serum for use with the Technicon Autoanalyzer I is described. Based upon the manual method of Persijn and Van Der Slik, adenosine formed by hydrolysis of 5'-AMP is deamined enzymatically and ammonia determined with the Berthelot reaction. The non specific alkaline phosphatases are inhibited by phenylphosphate. Concentrations of 5'-AMP and phenylphosphate are discussed. Nucleotidase activity is determined without dilution up to a value of 210 UI/liter. The precision is better than other manual or semi-automated methods in current use.

Adenosine Deaminase↗
PubMedDate not supplied

[Effect of detergents on the solubilization of 5'-nucleotidase from the thyroid gland].

The effect of Triton X-100, sodium deoxycholate and saponin upon the solubilization of 5'-nucleotidase, the membrane enzyme derived from pig thyroid was studied. Triton X-100 at the concentration of 0.1% did not cause enzyme solubilization, whereas at the concentration of 1.0% it caused only partial release of the former from the membranes. Saponin (1.0% concentration) brought about a marked (about threefold) increase in the enzyme activity which resulted from the exposing active loci of the enzyme, however it did not cause total solubilization of it. 1% sodium deoxycholate increased the enzyme activity by 5 times and also caused its almost total solubilization (over 90%). The results indicate the 5'-nucleotidase is strongly bound to the cell membranes and the non-ionic detergents like Triton X-100 and saponin do not fit for the solubilization of this enzyme.

5'-Nucleotidase↗
PubMed1979

Chemoarchitectonics in a reptilian cerebral hemisphere--acid phosphatase and 5'-nucleotidase.

Variations on the distribution of acid phosphatase and 5'-nucleotidase were observed among the cerebral nuclei of the Uromastix hardwickii. Most of the nuclei revealed more intensely positive reaction for 5'-nucleotidase than the acid phosphatase. However, an identical enzymatic pattern, demonstrating intense activity for the two enzymes, was observed in the cortical centers excepting the primordial hippocampus. The possible causes of the intensity and the functions of the enzymes were established in relation to the nuclei and fiber bundles.

Acid Phosphatase↗
PubMedDate not supplied

[Comparison of the activity and properties of 5'-nucleotidase in the homogenates and plasma membranes of the normal liver, hepatomas and of the liver in mice with inoculated hepatomas of varying degrees of malignancy].

Activity of 5'-nucleotidase was significantly lower in plasmatic membranes of highly malignant hepatoma 22 as compared with the activity found in normal liver tissue. The optimal activity of the enzyme from hepatoma 22 was found at pH 8.5 with AMP as a substrate. Decrease of pH value from 8.5 to 7.4 did not affect the enzymatic activity in homogenates and plasmatic membranes in the normal liver tissue. In all the experiments activity of 5'-nucleotidase was lower towards CMP as compared with AMP. The additive effect of the both substrates was observed only in experiments with hepatoma 22.

Adenosine Monophosphate↗
PubMed1980

Amniotic fluid alkaline phosphatase, gamma-glutamyltransferase, and 5'-nucleotidase activity from 13 to 40 weeks' gestation, and alkaline phosphatase as an index of fetal lung maturity.

Reference ranges for amniotic fluid alkaline phosphatase, gamma-glutamyltransferase, and 5-nucleotidase are described from 13 to 40 weeks' gestation. Gamma-glutamyltransferase and 5-nucleotidase activities peak early in the second trimester and then decrease to low values. Alkaline phosphatase shows a similar pattern of activity from 13 to 29 weeks' gestation, but thereafter activity increases to term; this late increase is mainly related to the heat-labile particulate form of alkaline phosphatase. Total and heat-labile alkaline phosphatase alone or expressed as a ratio with gamma-glutamyltransferase can be used with or as an alternative to lecithin/sphingomyelin ratios in the investigation of fetal lung maturity. A total alkaline phosphatase activity of 0.36 mukat/L and an alkaline phosphatase/gamma-glutamyltransferase ratio greater than 2 indicate pulmonary maturity.

Alkaline Phosphatase↗
PubMed1980

[ATPase and 5-nucleotidase in human breast and stomach tumors].

It has been concluded from the studies on the activity and location of ATPase and 5-nucleotidase in mammary and gastric tumours that some neoplasms of the mammary gland and stomach showing a high ATPase activity are histochemically related, in the former case, to the lobular myoepithelium and in the latter case, to non-differentiated cells of gastric glands which acquired a capacity for intestinal metaplasia and preserved it in the course of malignant transformation. No essential changes have been recorded in the activity of 5-nucleotidase, depending on the tumour histologic structure and degree of its maturity.

Adenosine Triphosphatases↗
PubMed1978

Vectorial production of adenosine by 5'-nucleotidase in the perfused rat heart.

Rat hearts were perfused simultaneously with [8-3H] AMP and [8-14C]adenosine. [8-3H] AMP was hydrolzyed by 5'-nucleotidase to produce intra- and extracellular [8-3H] adenosine. Comparison of the specific activities of [3H]- and [14C]adenosine in the heart cells with the specific activities of [3H]- and [14C]adenosine in the effluent perfusate showed that much more [3H]adenosine accumulated in the tissue than would be expected if extracellular adenosine were the immediate precursor of intracellular adenosine. Conversely, perfusion of rat hearts with [8-14C]AMP and [8-3H]adenosine led to a much greater accumulation of intracellular [14C]adenosine than would be expected from an uptake of adenosine from the perfusate. These results are interpreted to be due to hydrolysis of extracellular AMP by 5'-nucleotidase, located in the plasma membrane, and release of the resulting adenosine inside the cell. Measurements of the specific activities of 3H and 14C in ATP, ADP, AMP, and inosine support this interpretation.

Adenosine↗
PubMed1980

Serum sialyltransferase and 5'-nucleotidase as reliable biomarkers in women with breast cancer.

Sialyltransferase and 5'-nucleotidase were measured in the sera of 135 women with breast cancer: 53 undergoing mastectomy for primary cancer and 83 receiving different modalities of palliative therapy for metastatic disease. The objective of this study was to determine whether these enzyme levels were associated with the extent of the disease and whether changes in these enzyme levels could be correlated with success or failure of treatment. Mastectomy caused a rapid fall of elevated enzyme levels to within the normal range in all patients with stage I breast cancer but not in those with stage II or III disease. In women with metastatic disease, elevated enzyme levels fell only in patients responding to treatment. Thus serum sialyltransferase and 5'-nucleotidase activities are reliable biomarkers of breast cancer activity, and serial measurement of these enzyme activities provides a useful tool for the monitoring of disease activity and success or failure of the treatment.

Adolescent↗
PubMedDate not supplied

A comparative histochemical mapping of acid phosphatase, 5-nucleotidase and non-specific esterase in the olfactory bulbs of rabbit and hedgehog.

The paper deals with comparative account of the distribution of acid phosphatase 5-nucleotidase and non-specific esterase in the olfactory bulbs of rabbit and hedgehog. The acid phosphatase is observed in all the neurons of both the animals. However, the concentration of the enzyme is higher in hedgehog as compared to rabbit. The intensity of 5-nucleotidase in all the layers of olfactory bulb of hedgehog is stronger than in the rabbit. Intensity of non-specific esterase is quite higher in the olfactory bulb of rabbit than of hedgehog. Along with comparison the distribution of these enzymes have been correlated with their role in the olfactory senses.

Acid Phosphatase↗
PubMed1981

5-Nucleotidase in liver injury induced by heavy metals. A histochemical study.

The alterations in the distribution of 5-nucleotidase being the indicator of the functional state of liver parenchyma have been determined histochemically in the rat (Rattus rattus albino) after experimental poisoning with a few heavy metals viz. lead, mercury, cadmium, molybdenum, copper, and zinc that possess considerable environmental and nutritional significance. Present results show that all these metals affected the distribution and activity of 5-nucleotidase that has been explained on the basis of binding affinity of these metals, state of plasma membrane, resorption of nucleotides and variations in the level of enzyme protein. Presumably, all these factors have implications for the interpretation of observed changes in enzyme activity and are specific to each metal.

Animals↗
PubMedDate not supplied

[5'-Nucleotidase as an "internal probe" in studying steroid hormone interaction with the plasma membranes of target cells].

Changes in the activity of 5'-nucleotidase, the marker enzyme of plasma membranes, in membrane cells of the uterus and liver were examined upon action of tropic and nontropic steroid hormones. In case of tropic steroids, the curves of changes in the activity with rise in the hormone concentration are complicated and broken with a marked minimum at 10(-8) M. Upon the action of nontropic hormones there takes place a monotonous rise in the enzymatic activity. The characteristic differences as shown by the curves make it possible to apply 5'-nucleotidase as endogenous probe during studies into hormone-membrane interactions.

Animals↗
PubMed1978

Absence of any detectable activity of the membrane marker enzyme 5'-nucleotidase in human red blood cells.

We have investigated in human red blood cell membranes the presence of a 5'-nucleotidase, which is considered a general marker of plasma membranes. No activity was detectable with a highly sensitive colorimetric method. This absence is not due to the rapid decline of enzyme activity in the course of red cell ageing, nor to its release during membrane preparation; nor is it due to substrate accessibility hindrance to the active center of the enzyme. Thus, the ubiquitousness of 5'-nucleotidase in plasma membranes is questioned.

Cell Membrane↗
PubMedDate not supplied

[Effect of antibodies specific to sarcolemma of cardiomyocytes in activity of 5-nucleotidase in rats].

Rabbit antibodies specific to sarcolemma of cardiomyocytes have been studied for their effect on activity of 5'-nucleotidase ecto-enzyme of the Wistar rat cardiomyocytes. It is shown that incubation of isolated plasma membranes of cardiomyocytes of rats (100 micrograms of protein) with the gamma-globulin fraction of antisarcolemmal cardial serum (gamma-ASCS, 20 micrograms protein) and with the gamma-globulin fraction of normal rabbit serum (gamma-NRS, 0.20 micrograms protein) promotes a decrease of the enzyme activity. An inhibiting effect was greatly pronounced in incubation with gamma-NRS and did not depend on the dose of antibodies and duration of their action. An assumption is made that inhibiting action of antibodies on activity of ecto-5'-nucleotidase may change adenosine concentration and may be one of elements in the mechanism promoting an increase of the intracellular calcium concentration.

5'-Nucleotidase↗
PubMed1995

Serum adenosine deaminase, 5'-nucleotidase & alkaline phosphatase in breast cancer patients.

Serum levels of adenosine deaminase (ADA), 5-nucleotidase (5'-NT) and alkaline phosphatase (ALP) were studied in 25 patients of carcinoma breast and 25 normal subjects. Adenosine deaminase was found to be the better probable parameter for the detection of cancer and to assess the development of various stages of cancer whereas 5'-nucleotidase had only diagnostic significance. Serum alkaline phosphatase levels were important for assessing the spread of cancer at secondary sites. After mastectomy a significant decrease was found in the levels of serum ADA and 5'-NT whereas no variations were found in case of serum ALP.

5'-Nucleotidase↗