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)

The distribution of haloperidol-sensitive (+)[3H]N-allylnormetazocine ((+)[3H]SKF-10,047) binding sites (sigma sites) in subcellular fractions of rat brain homogenates was extensively characterized. In synaptosomal fractions, enriched in choline acetyltransferase activity, sigma sites were present in lower concentrations than in whole brain homogenates. On the other hand, microsomal and myelin fractions were found to be enriched in sigma sites. A similar pattern of enrichment was seen for 5'-nucleotidase activity, a general plasma membrane marker. However, subsequent experiments in which microsomes were subfractionated on linear sucrose gradients led to the recovery of sigma sites over a significantly lower density range than 5'-nucleotidase activity or ATP-stimulated [3H]ouabain binding, an additional plasma membrane marker. In addition, previously reported distributions of a number of other subcellular markers, including those for endoplasmic reticulum, were found to contrast with the observed distribution of sigma sites. It is concluded that rat brain sigma sites are not concentrated at synaptic regions of plasma membrane. However, the possibility that sigma sites are localized to specialized areas of nonsynaptic plasma membrane cannot be excluded.
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PMID:Haloperidol-sensitive (+)[3H]SKF-10,047 binding sites (sigma sites) exhibit a unique distribution in rat brain subcellular fractions. 216 73

Biochemical examinations of brain tissue samples obtained from patients with Alzheimer's disease have revealed a decreased quantity of the neurotransmitter acetylcholine and reduced activity of choline acetyltransferase (ChAT), the enzyme responsible for acetylcholine formation. It has been suggested that the choline moiety of lecithin, a substitute ubiquitously present in membranes of mammalian cells, could be mobilized for acetylcholine formation. The activity of phospholipase D, an enzyme which releases choline directly from lecithin, was measured in homogenates of Alzheimer brain tissue and found to be reduced by 63%. ChAT activity was reduced by 58% and 5'-nucleotidase activity was reduced by 27% in these homogenates.
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PMID:Reduced phospholipase D activity in brain tissue samples from Alzheimer's disease patients. 301 30

A biochemical study of a case affected by Creutzfeldt-Jakob disease is reported. Changes were found in soluble and insoluble proteins, glycoproteins and mucopolysaccharides and in total lipids, glycolipids, phospholipids and gangliosides. Also CNPase, choline acetyltransferase, 5'-nucleotidase and several glycosidases have an altered activity. All these data give a complete neurochemical pattern of the changes underlying the morphological and functional alterations in this disease.
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PMID:Neurochemical changes in Creutzfeldt-Jakob disease. 615 3

Heterosis (hybrid vigor) for brain myelin content has been examined in detail in (C57BL/6J x DBA/2J)F1 hybrid mice at 17 days of age. The amount of myelin isolated from the F1 hybrid brain is greater than that isolated from either parental strain. In addition, the total protein content in the myelin of the three genotypes showed the following trend: F1 greater than DBA greater than C57. However, no discernible differences in myelin protein compositions could be detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of the whole brain for several myelin-associated constituents such as GM1 ganglioside, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase), 5'-nucleotidase, and carbonic anhydrase indicated that heterosis exists for these components. No heterosis was found for such nonmyelin constituents as gangliosides GD1a, GT, GQ, RNA, DNA, and choline acetyltransferase. A developmental study of the whole brain CNPase indicated that the heterotic effect was greatest during the most active period of myelination (17-30 days). We conclude that the heterotic effect is specific for myelin content and is probably the result of an accelerated myelin synthesis. The heterotic effect should have great potential as a new model for studying aspects of myelinogenesis.
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PMID:Biochemical study of heterosis for brain myelin content in mice. 618 36

Brain extracts from 8-day-old chick embryos have been shown to influence morphological development of dissociated brain cells from 7-day-old chick embryos in culture. Stimulatory effects on size of the neuronal somas and on growth of long processes were observed by adding the cytosol of the brain extract or the dialysate of the cytosol. These morphological changes parallel modifications of various enzyme activities according to the age of the cultures. Adenyl cyclase, (Na+,K+)- and Mg2+-ATPase, 5'-nucleotidase, choline acetyltransferase, and acetylcholinesterase activities were studied between 5 and 14 days of culture. Adenyl cyclase activity was strongly stimulated at 8 days by both extracts. (Na+,K+)- and Mg2+-ATPase activities were stimulated in 8-day-old cultures only by the dialysate. 5'-Nucleotidase activity was stimulated in 8-day-old cultures by the dialysate and in 11-day-old cultures by both extracts. Choline acetyltransferase activity was stimulated by the cytosol in 8-day-old cultures and by the dialysate in 11-day-old cultures. The total acetylcholinesterase activity was higher in 8-, 11-, and 14-day-old cultures treated with the cytosol. When the cells were treated with the dialysate, the activity was only higher in 14-day-old cultures. We also found that following the addition of brain extracts, the specific activity of the enzymes we studied was enhanced and became close to the values found in vivo during embryogenesis. Thus in parallel to the morphological modifications observed in nerve cell cultures treated by embryo brain extracts, biochemical variations especially involved in synaptogenesis and membrane development could be measured.
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PMID:Study of some enzyme activities in cultured chick embryo brain nerve cells treated by chick embryo brain extracts. 625 93

Nerve terminals prepared from rat cortex and hippocampus were loaded with seven radioactive putative neurotransmitters (serotonin, noradrenaline, dopamine, gamma-aminobutyric acid, aspartate, glutamate, and taurine). The release of these transmitters, choline acetyltransferase, 3,4-dihydroxyphenylalanine decarboxylase, enolase, and lactate dehydrogenase was monitored during complement-mediated lysis. Three antisera were used: anti-5'-nucleotidase, anti-Chol-1, and anti-rat cerebrum. Anti-5'-nucleotidase serum did not cause the release of any labelled transmitter or of any of the enzymes studied. Anti-Chol-1 serum released choline acetyltransferase and small amounts of enolase and lactate dehydrogenase. Anti-rat cerebrum caused the release of all seven transmitters, choline acetyltransferase, and small amounts of the other three enzymes. It was concluded that 5'-nucleotidase was not present on any of the terminals studied, and that Chol-1 is only present on cholinergic terminals.
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PMID:Presynaptic distribution of the cholinergic-specific antigen Chol-1 and 5'-nucleotidase in rat brain, as determined by complement-mediated release of neurotransmitters. 630 66

Semi-purified diets supplemented with either a high alpha-linolenate (n - 3) (perilla) oil or a high linoleate (n - 6) (safflower) oil were fed to rats through two generations. Rats fed safflower oil showed a decrease in docosahexaenoic acid (n - 3) and a compensatory increase in docosapentaenoic acid (n - 6) in all the brain regions and organelles examined, when compared with rats fed perilla oil. As reported previously, the safflower oil-fed rats exhibited inferior learning ability compared with the perilla oil-fed rats (N. Yamamoto et al., J. Lipid Res. 28, 144 (1987)). Using brains of rats in these dietary groups, the activities of several enzymes, Na+ , K+-ATPase, Ca2+-ATPase, 5'-nucleotidase, 2',3'-cyclic nucleotide phosphodiesterase, acetylcholinesterase, and choline acetyltransferase in membranes, were compared. The 5'-nucleotidase activity in cortex and hippocampus, and the Na+, K+-ATPase activity in myelin decreased slightly but significantly in the safflower oil group. None of the other membrane-associated enzyme activities in all the brain regions and organelles examined was affected significantly by the dietary fatty acids under optimal assay conditions in vitro. However, in the safflower oil group, the Na+, K+-ATPase activity of synaptosomes at a suboptimal concentration of ATP was 78% that in the perilla oil group. These results suggest that relatively large changes in the proportions of n - 3 and n - 6 polyunsaturated fatty acids in brain membranes caused by dietary manipulation do not provoke significant alterations in most membrane-bound enzyme activities. However, a small but significant change in Na+, K+-ATPase activity at a suboptimal concentration of ATP may be implicated in the altered learning behavior reported earlier.
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PMID:Effect of a high alpha-linolenate and high linoleate diet on membrane-associated enzyme activities in rat brain--modulation of Na+, K+- ATPase activity at suboptimal concentrations of ATP. 749 79

The subcellular distribution of the adenosine A2a receptor in rat striatum has been investigated using specific binding of the A2a-selective ligand [3H]-CGS 21680. After subcellular fractionation, the distribution of [3H]-CGS 21680 binding was similar to that of the cholinergic nerve terminal marker acetylcholinesterase rather than the more general membrane marker 5'-nucleotidase, with 42% of binding associated with the synaptosomal sub-fraction and 19% with a light membrane fraction. Binding of [3H]-CGS 21680 was also found to co-purify with the cholinergic nerve terminal marker choline acetyltransferase during immunoaffinity purification of striatal cholinergic nerve terminals. These results demonstrate that some adenosine A2a receptors are present on cholinergic nerve terminals in rat striatum.
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PMID:The subcellular distribution of [3H]-CGS 21680 binding sites in the rat striatum: copurification with cholinergic nerve terminals. 836 37