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)

Liver metastases due to the more common neoplastic diseases such as colorectal, breast, or bronchogenic carcinoma are a frequent occurrence and are associated with an ominous prognosis. Earlier detection followed by appropriate therapeutic interventions might have a decided effect on the subsequent course of disease. Controversy exists over the selection of tests with the greatest sensitivity, specificity, and potential utility. Preliminary evidence suggest that gamma-glutamyl transpeptidase and 5'-nucleotidase may be of particular significance. Four enzymes--gamma-glutamyl transpeptidase, 5'-nucleotidase, leucine aminopeptidase, and alkaline phosphatase plus carcinoembryonic antigen--were compared in the same blood samples from selected patients with breast and small cell carcinoma of the lung. Gamma-Glutamyl transpeptidase was the most sensitive test with 28/29 (97%) patients with hepatic metastases having elevated enzymatic activity in their sera. For patients with small cell carcinoma of the lung followed serially, gamma-glutamyl transpeptidase activity was increased an average of 5 months before liver metastases were detected by clinical means. Two factors are important in the interpretation of the results of gamma-glutamyl transpeptidase analysis: (1) Hepatic dysfunction due to diseases other than metastatic tumor involvement can cause a rise in enzyme levels as can (2) medications or ethanol which activate the hepatic microsomal drug metabolizing system. Of particular importance, however, is the fact that antitumor chemotherapy, even intensive and multiple agent, did not appear to effect the enzyme activity in the sera of patients with breast or small cell carcinoma of the lung. Gamma-glutamyl transpeptidase in combination with carcinoembryonic antigen may be of particular value in detecting liver metastases and in assessing subsequent response to therapy.
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PMID:Biological markers as an aid in the clinical management of patients with liver metastases. 612 62

The activity of plasma membrane marker enzymes which are involved in purine metabolism (5'-nucleotidase, alkaline 5'-nucleotide phosphodiesterase), in active ion transport (Na-K-Mg-adenosine triphosphatase, ouabain-sensitive Na-K-adenosine triphosphatase), in aminoacid transport (gamma-glutamyltranspeptidase), and in basic physiologic functions (alkaline phosphomonoesterase) were assayed in mononuclear cells isolated from peripheral blood of normal donors and of patients with primary immunodeficiency. Irrespective of the clinical classification of the immunodeficiency, the cells of patients were characterized by significantly diminished 5'-nucleotidase and to a certain extent by lower alkaline phosphomonoesterase activities. Average activity levels of other enzymes were similar in cells of patients and controls, but scattering was more pronounced in the first group. Determination of substrate affinity revealed different kinetic properties of 5'-nucleotidase in cells from patients and normal donors; however, the extent of inhibition by beta-glycerophosphate or alpha, beta-adenosine-methylene diphosphate was comparable for both types of cells. The presence of inhibitory compounds in patients' serum was excluded by mixing experiments. When activities of the various plasma-membrane-associated enzymes were compared with each other, significant correlations emerged in normal lymphocytes. Most of these correlations were absent in cell membranes of immunodeficient patients. The findings indicate that the plasma membrane of lymphocytes from patients with immunodeficiency may be characterized by an altered distribution of enzymatic constituents.
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PMID:Correlations between enzymatic and immunologic properties of human peripheral blood mononuclear cells. I. Ectoenzymes of normal and immunodeficient peripheral blood mononuclear cells. 612 61

In experimental bile obstruction the serum activities of the membrane-bound liver enzymes, alkaline phosphatase, 5'-nucleotidase and gamma-glutamyltransferase are greatly increased, whereas in the liver only the alkaline phosphatase activity is elevated. After partial hepatectomy or tetrachloride poisoning the alkaline phosphatase activity in the regenerating live is increased to the same extent as in cholestasis without an accompanying elevation in serum activity. The following results support the hypothesis of a bile salt-mediated solubilization of membrane-bound enzymes in cholestatic liver: (1) 30 min after bile duct ligation the total bile acids in the liver were increased 5-fold, 2 h later as much as 10-fold. After 1 day, the bile acid concentration was still 4 times above normal. (2) Isolated plasma membranes from normal and obstructed livers were incubated in vitro with increasing amounts of tri- and dihydroxycholanic acids. At a final concentration of 1 mmol/l taurochenodeoxycholate significant amounts of membrane-bound enzymes were released into the 12,000-g supernatant. (3) In the regenerating liver, where tissue phsophatase activity was high and serum phosphatase activity unchanged, the bile salt concentration was not increased.
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PMID:Studies on the mechanism of the increase in serum alkaline phosphatase activity in cholestasis: significance of the hepatic bile acid concentration for the leakage of alkaline phosphatase from rat liver. 612 56

Two nutritional models, an essential fatty acid deficiency model and the feeding of saturated versus unsaturated fats, were used in a feeding study in order to assess the relationship between tissue fatty acid composition and the activities of some membrane-associated enzymes. Purified diets containing 7% hydrogenated coconut oil, 7% corn oil, 10% safflower oil or butter were fed to rats for a total of 49 weeks (1 week of pregnancy, 3 weeks of lactation and 45 weeks post-weaning). Tissue homogenates from submandibular salivary glands and kidneys were analyzed for fatty acid composition of total lipids and phospholipids. Changes in fatty acid patterns typical of essential fatty acid deficiency such as an increase in the levels of 16:1 and 18:1, a decrease in 18:2 and 20:4 and an accumulation of 20:3 omega 9 were observed in salivary glands and kidneys of rats fed the deficient diet. Tissues of rats fed 10% butter also showed fatty acid compositional changes which were somewhat similar to those in essential fatty acid deficiency, but to a lesser degree. The activities of ouabain-sensitive (Na+ + K+)-ATPase were higher in homogenates of salivary glands and kidneys of the deficient rats and those fed butter as compared with their controls. The results suggest a relationship between the double bond index of fatty acids as an indication of membrane lipid fluidity and allosteric modification of (Na+ + K+)-ATPase activity. However, other explanations for the observed changes in (Na+ + K+)-ATPase activity cannot be ruled out. There were no diet-related differences in the activities of gamma-glutamyltranspeptidase or 5'-nucleotidase.
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PMID:ACYL group composition of lipids and the activities of (Na+ + K+)-ATPase, 5'-nucleotidase and gamma-glutamyltranspeptidase in salivary glands and kidneys of rats fed diets containing different dietary fats. 613 56

After 6 weeks of chronic ethanol consumption hepatic gamma-glutamyl-transferase and -hydrolase activities increased compared with pair-fed controls. There was no change in 5'-nucleotidase activity. It was found that the increase in gamma-glutamyltransferase activity occurred exclusively in the parenchymal cells although the principal cellular localisation for this enzyme is the biliary tract in both control and ethanol-fed rats. In both groups of animals the gamma-glutamyltransferase activities were localised by analytical subcellular fractionation techniques to soluble, plasma membrane and canalicular fractions, but the plasma membrane activity was selectively increased in the ethanol-fed rats.
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PMID:Effect of chronic ethanol consumption on the cellular and subcellular distribution of gamma-glutamyltransferase in rat liver. 614 45

The effects of a chronic 8- to 12-week administration of the hepatic tumor promoter, phenobarbital, on further altering the biochemical enzyme deviation patterns shown by hyperplastic liver nodules was examined in rats previously subjected to the initiation/selection protocol of Solt and Farber. Hyperplastic liver nodules of various size classes from the phenobarbital-treated group exhibited a significant increase in GGT specific activity, as well as 2- to 3-fold higher levels of microsomal cytochrome P-450 than was shown by control nodules. The increase in GGT specific activity was also found in many cases to be higher in those hyperplastic liver nodules from the phenobarbital-treated group with diameters greater than 3.0-3.5 mm than in nodules of a smaller size. In contrast, the GGT specific activity of the control nodules did not correlate with differences in their sizes. Furthermore, while histochemical staining of GGT activity appeared uniform in sections of the various sized hyperplastic nodules from the phenobarbital-treated group, biochemical measurements indicated a consistently higher specific activity for this enzyme in tissue taken from the central portion of the nodule than in tissue from the peripheral portion of the nodule. On the other hand, the specific activities of glucose-6-phosphatase, 5'-nucleotidase, and fructose-1,6-diphosphate aldolase of the hyperplastic liver nodules were not found to be significantly altered over control values by the chronic phenobarbital treatment, suggesting a stability of these other marker enzyme alterations during the early promotional phase of hepatocarcinogenesis.
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PMID:Effect of phenobarbital on the altered biochemical phenotypes expressed by hyperplastic liver nodules during hepatocarcinogenesis in the rat. 614 62

The present investigations on rat lung show that metabolic changes occurring around the 20th gestational day are accompanied by multiple alterations in the quantitative pattern of enzymes. This involves increases in two lysosomal enzymes (N-acetyl beta-glucosaminidase and beta-galactosidase) and a rise and fall in pyruvate kinase and alpha-glucosidase. The striking transient upsurge of adenylate kinase, however, is postponed until after birth. The normal diminution of thymidine kinase and peptidylproline hydroxylase is drastically enhanced by an injection of cortisol to fetal rats. Studies on human pulmonary tissues consisted in determining enzyme concentration from the ninth to the 21st week of gestation and an histologically normal adult lungs. The results show that the 15th to the 21st week of gestation is the period of increase in pyruvate kinase, adenylate kinase and alpha-glucosidase. The rise during the development of several enzymes (e.g., 5'-nucleotidase, alkaline phosphatase, and gamma-glutamyl transpeptidase) and the decline in thymidine kinase and peptidylproline hydroxylase, however, dose not begin until after the 21st week of gestation.
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PMID:Phosphotransferases and lysosomal enzymes in fetal human and rat lung. 626 41

To evaluate the potential role of taurine deficiency in the pathogenesis of parenteral nutrition-induced cholestasis, 20 premature (less than 34 weeks AGA) infants were randomized to receive parenteral nutrition with and without taurine (10.8 mg/kg/day) during the first 10 days of life. Birth weight, gestational age, and protein and caloric intake were similar in both groups. Plasma taurine levels and hepatic function were assessed before the study began (3 +/- 1 days of age), at 5 +/- 1 days of age, and at 9 +/- 1 days of age. Although plasma taurine levels were significantly greater at 5 +/- 1 and 9 +/- 1 days of age (p = 0.009) in the group receiving supplementation, no differential effect on hepatocellular function could be detected during this short period of time. A decrease in plasma ammonia (p = 0.001), alanine aminotransferase (ALT) (p = 0.036), gamma-glutamyltranspeptidase (GGTP) (p = 0.05), 5'-nucleotidase (5'N) (p = 0.001), and bile salt concentrations was noted in both groups, indicating the rapid maturation of hepatic function even in the presence of parenteral nutrition during the first 10 days of life.
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PMID:Effect of taurine supplementation on hepatic function during short-term parenteral nutrition in the premature infant. 642 96

Plasma membranes were isolated from lactating bovine mammary gland. Two crude membrane fractions; medium/d 1.033 (light membrane) and 1.033/1.053 interfaces (heavy membrane), were obtained by Ficoll density gradient centrifugation of osmotically washed microsomal fraction. Two crude membranes were further purified separately by sucrose density gradient centrifugation. Both light and heavy membranes banded at a sucrose density of 1.14. The purified membranes appeared as heterogeneous smooth membrane vesicles on electron microscopy. The contaminating suborganelles were not detected. The yield of the purified membranes relative to the homogenate was 1.2%. The degree of purity of the membranes was shown by a great increase in the specific activity of 5'-nucleotidase over the homogenate of 20-fold for light membrane and of 16-fold for heavy membrane. The relative activities of Mg2+-ATPase, (Na+ + K+)-ATPase, gamma-glutamyl transpeptidase, phosphodiesterase I, alkaline phosphatase and xanthine oxidase were also high (12-18-times) and nearly 20% of these enzymes was recovered. The activity of marker enzyme for mitochondria, endoplasmic reticulum and Golgi apparatus was very low, while that of acid phosphatase for lysosome was relatively high (5-times). DNA and RNA contents were very low. The major polypeptides rich in other suborganelles were not detected profoundly in the membrane fraction and the polypeptide composition in both light and heavy membranes were similar upon SDS-polyacrylamide gel electorphoresis.
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PMID:Isolation and characterization of plasma membrane from lactating bovine mammary gland. 720 55

Dogs are particularly susceptible to development of glucocorticoid-induced hepatopathy, but the mechanisms are not well understood. We investigated the pathogenesis of glucocorticoid hepatopathy by examining sequential morphologic and biochemical changes in the liver of dogs during steroid administration. Six adult Beagles were given prednisolone acetate (4mg/kg of body weight, once daily for 24 days IM). Serum samples and percutaneous liver biopsy specimens were obtained before the start of the study (treatment day [TD] 0) and at TD 5, 10, 15, and 25. There were significant (P < 0.05) and progressive increases in serum activities of alkaline phosphatase, gamma-glutamyltransferase, and alanine transaminase. Light microscopic changes in liver biopsy specimens included progressive hepatocellular swelling and vacuolation. Electron microscopy revealed glycogen accumulation, peripheral displacement of organelles, and prominent dilatation of bile canaliculi, compared with findings at TD 0. Liver biopsy specimens taken at TD 25 had significantly (P < 0.05) increased activities of the plasma membrane enzymes, alkaline phosphatase and gamma-glutamyltransferase, and 5'-nucleotidase was significantly (P < 0.001) decreased. Subcellular fractionation on reorientating sucrose density gradients revealed high-density peaks of alkaline phosphatase and gamma-glutamyltransferase, compatible with a specific increase in the biliary canalicular component of the enzyme activities. Neutral alpha-glucosidase activity was shifted to the denser fractions, indicative of an increase in the proportion of rough to smooth endoplasmic reticulum and consistent with enhanced synthesis of plasma membrane proteins. There also was evidence for progressive increase in fragility of intracellular organelles, particularly lysosomes. These findings indicate that glucocorticoid hepatopathy in dogs is associated with progressive alterations not only to the plasma membrane, but also to other subcellular organelles.
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PMID:Subcellular pathologic features of glucocorticoid-induced hepatopathy in dogs. 757 58


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