Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An abnormal flux of monovalent cations may be related to the epileptogenic process in man. One possible mechanism for deranged electrolyte metabolism in epileptic brain is an abnormality in sodium, potassium-dependent adenosine triphosphatase (Na, K ATPase). We found the activity of Na, K ATPase to be significantly less in epileptic human corfex than in nonepileptic cortex. Histological changes have been simultaneously evaluated in epileptic brain. A second membrane-bound enzyme, acetylcholinesterase (AChE), was also assayed as a marker for neuronal membranes and found not to correlate with the epileptogenicity of human brain. In addition, the concentrations of the anticonvulsant compound phenytoin have been determined in the serum and cerebral cortex of epileptic and nonepileptic patients. The ratio of phenytoin in cortex to serum concentration is significantly lower in epileptic patients than in nonepileptic controls.
 ...
PMID:Human epileptic brain Na, K ATPase activity and phenytoin concentrations. 12 76

The thoracic muscles of Drosophila melanogaster can be classified into two classes, the fibrillar and the tubular muscles, on morphological grounds. Histochemical techniques were used to characterize these two classes of muscle according to their content of various enzymes (alpha-glycerophosphate, NAD-dependent isocitrate, malate and succinate dehydrogenases, fumarase, acid phosphatase, adenosine triphosphatase and acetylcholinesterase) and of glycogen. These investigations showed that the two muslces types are histochemically very different and, further, that the morphologically similar tubular muscles are heterogeneous with respect to their enzyme content. In particular, the tergal depressor of the trochanter of the second leg, the largest of the tubular muslces, has considerably less of all the enzymes studied, with the exception of acetylcholinesterase, than all the other tubular muscles examined. The histochemical techniqes were also used to follow the changes in enzyme levels that occur during development of the indirect flight muscle fibres. All the enzymes that are present in adult flight muslces showed an increase in staining intensity throughout muscle development. Some minor differences were observed in the time of appearance and rate of increase of intensity of the different enzymes.
 ...
PMID:A histochemical study of the muscles of Drosophila melanogaster. 14 43

A zonal rotor technique for the preparation of synaptosomes in bulk from bovine brain frontal cortex based on an impirical transformation of a small-volume discontinuous sucrose density gradient arrangement is presented in detail. The procedure yields new information concerning synaptosomes prepared in sucrose gradients. Cerebroside analysis and electron microscopy show myelin contamination to be restricted to the leading, less dense edge of the synaptosomal profile, free mitochondria to the trailing, more dense edge. Exclusion of fringe areas yields a highly purified synaptosome preparation which entirely enters the next dense layer beyond the 0.8 : 1.2 M sucrose interface. This interface collects most of the oubain-sensitive (Na+, K+) adenosine triphosphatase activity. The purified synaptosomes display very high intrinsic sialidase activity and are rich in di-, tri-, and tetrasialogangliosides, the preferred substrates for the enzyme. Up to 90% of the cholinesterase activity in the zonal rotor synaptosome preparation is specific acetylcholinesterase.
 ...
PMID:Large-scale preparation of synaptosomes from bovine brain using a zonal rotor technique. 15 41

Cardiotoxin isolated from Naja mossambica mossambica selectively deactivates the sodium-potassium activated adenosine triphosphatase of axonal membranes. Tetrodotoxin binding and acetylcholinesterase activities are unaffected by cardiotoxin treatment. The details of association of cardiotoxin with the axonal membrane were studied by following the deactivation of the sodium-potassium activated adenosine triphosphatase and by direct binding measurements with a tritiated derivative of the native cardiotoxin. The maximal binding capacity of the membrane is 42-50 nmol of cardiotoxin/mg of membrane protein. The high amount of binding suggests association of the toxin with the lipid phase of the membrane. It has been shown that cardiotoxin first associates rapidly and reversibly to membrane lipids, then, in a second step, it induces a rearrangement of the membrane structure which produces and irreversible deactivation of the sodium-potassium activated adenosine triphosphatase. Solubilization of the membrane-bound ATPase with Lubrol WX gives an active enzyme species that is resistant to cardiotoxin-induced deactivation. Cardiotoxin binding to the membrane is prevented by high concentrations of Ca 2+ and dibucaine. Although cardiotoxins and neurotoxins of cobra venom have large sequence homologies, their mode of action on membranes is very different. The cardiotoxin seems to bind to the lipid phase of the axonal membrane and inhibits the sodium-potassium activated adenosine triphosphatase, whereas the neurotoxin associates with a protein receptor in the post-synaptic membrane and blocks acetylcholine transmission.
 ...
PMID:Molecular mechanism of cardiotoxin action on axonal membranes. 18 4

Dopa-decarboxylase, acetylcholinesterase, sodium plus potassium stimulated adenosine triphosphatase (Na+ + K+-ATPase), and membrane-bound protein kinase were compared in the erythrocytes of patients with Huntington's disease and normal controls. All these enzymes also exist in the basal ganglia. The Na+ +K+-ATPase level was elevated (p less than 0.05) in Huntington's disease, while no significant changes were observed in the other enzymes. This finding is consistent with the concept that Huntington's disease is associated with a general membrane abnormality.
 ...
PMID:Increased sodium plus potassium adenosine triphosphatase activity in erythrocyte membranes in Huntington's disease. 21 30

Four different oil-based diets were used in a feeding study involving rats to assess the relationship between the fatty acid composition of the dietary fat and its influence on erythrocyte membrane (EM) lipid composition and the activities of membrane-bound enzymes. Nutritionally adequate diets containing 20% groundnut (GNO), coconut (CO), safflower (SO), or mustard oil (MO) were fed to weanling CFY rats for 4 months. EMs were analyzed for total cholesterol, phospholipids, fatty acid profiles, and sialic acid content. Activities of membrane-bound enzymes such as Na+, K(+)-adenosine triphosphatase (ATPase), Mg(2+)-ATPase, Ca2+, Mg(2+)-ATPase, and acetylcholinesterase were also assayed. The activities of all membrane-bound enzymes, except Mg(2+)-ATPase, and sialic acid content were higher in the MO-fed group than in the rest of the groups. Ca2+, Mg(2+)-ATPase activity was distinctly lower in the SO-fed group than in the other groups. Cholesterol to phospholipid molar ratio was similar in all the groups. However, SO- and MO-fed groups displayed an increased cholesterol content and a higher degree of unsaturation in the membrane fatty acid composition. The higher membrane fatty acid unsaturation in the SO-fed group was principally due to linoleic (18:2) and arachidonic (20:4) acids, while in the MO-fed group it was mainly due to oleic (18:1), eicosenoic (20:1), erucic (22:1), and linoleic (18:2) acids. These results suggest a relationship between the quality of dietary fat, EM fatty acyl composition, and the activities of membrane-bound enzymes.
 ...
PMID:Effect of dietary fats on erythrocyte membrane lipid composition and membrane-bound enzyme activities. 131 27

Methyl isocyanate (MIC) interaction with the rabbit erythrocyte membrane increased the fluidity of the membrane and decreased the osmotic fragility of erythrocytes both in vitro and in vivo in rabbits intoxicated with MIC subcutaneously. MIC inhibited both acetylcholinesterase (AChE) and adenosine triphosphatase (ATPase) activities of erythrocytes dose-dependently in vitro, while in vivo a decreased trend in ATPase activity with unaltered AChE activity was observed. MIC also caused significant decrease in plasma sodium level with corresponding increase in potassium level in rabbits. The observed effects are due to MIC, per se, as the hydrolysis products of MIC, methylamine and N,N'-dimethylurea did not affect the erythrocyte fluidity and enzymes activities both in vitro and in vivo while they increased the osmotic fragility of erythrocytes in vivo in rabbits administered subcutaneously in equimolar concentration to MIC dosage. Inhibition of Na(+)-K(+)-dependent ATPase with altered permeability to cations and also probably water transport of plasma membrane due to MIC interaction are envisaged.
 ...
PMID:Acute toxicity of methyl isocyanate in rabbit: in vitro and in vivo effects on rabbit erythrocyte membrane. 153 91

The mechanism of the anaesthetic effect of toluene on the central nervous system (CNS) was studied by using rat erythrocyte and synaptosome membranes as nerve cell models both in vitro and in vivo. The activities of the membrane-bound integral enzymes acetylcholinesterase (AChE), total adenosine triphosphatase (total ATPase) and magnesium-activated adenosine triphosphatase (Mg2+-ATPase) were determined. A short-term exposure to 2000 p.p.m. of toluene had an inhibitory effect on the enzyme activities studied. The degree of inhibition in erythrocyte membranes in vitro and in vivo, and in synaptosome membranes in vitro were in good correlation. In in vivo conditions, the synaptosome-bound enzymes were, however, significantly more inhibited by toluene, which indicates that membranes in vivo are even more vulnerable to the toxic effects of organic solvents than they are as isolated membranes in vitro. However, our results show that in vitro experiments can be used to predict the toxic nerve cell membrane effects of organic solvents. Toluene caused similar enzyme inhibitions both in neural cell membranes and in erythrocyte membranes. Thus, even peripheral non-excitable cell membranes, like erythrocytes, can be used as nerve cell membrane models in studies on the mechanism of the anaesthesia caused by solvents.
 ...
PMID:The effect of in vitro and in vivo toluene exposure on rat erythrocyte and synaptosome membrane integral enzymes. 296 6

Six rhabdomyosarcomas were assessed by means of a battery of enzyme histochemical methods. The reactions were compared with those of a small number of other tumours belonging to the small-cell tumour category. Four of the rhabdomyosarcomas were positive for myophosphorylase and acetylcholinesterase. Myoblasts were strongly reactive for adenosine triphosphatase at alkaline pH and after acid pre-incubation, whereas the small undifferentiated neoplastic cell of the four alveolar rhabdomyosarcomas showed also discernible cytoplasmic reaction, but only after acid pre-incubation. Other tumour categories revealed positive staining for adenosine triphosphatase with acid pre-incubation but the degree of reaction was minimal by comparison. Other enzyme reactions were variable and, generally, did not distinguish between different tumour categories. It is concluded that enzyme histochemistry has a potential role in the diagnostic evaluation of the small cell tumour and should be included in the growing list of special techniques that may assist the pathologist confronted with this problem.
 ...
PMID:An evaluation of enzyme histochemistry in the diagnosis of childhood rhabdomyosarcoma. 315 41

A cryostat retrieval method and combined adenosine triphosphatase (ATPase) and acetylcholinesterase (AChase) method were used to study the ultrastructure and innervation of histochemically identified skeletal muscle fibers in different pigeon muscles. The Z-line structure and volume percentage sarcotubular system were analyzed from different muscles selected for their composition by fiber type. Histochemically, three main fiber types were investigated: slow tonic fibers with a moderate ATPase activity after preincubation at acid or alkaline pH; fast-twitch fibers that had high activity after alkaline treatment and low activity after acid preincubation; and a type considered to be slow-twitch that had low activity after alkaline, and high after acid preincubation. Both the slow tonic and slow-twitch fibers had multiple, en grappe innervation, while the fast-twitch fibers had robust, single end plates. The Z-line of the fast-twitch and slow-twitch fibers had a regular square lattice pattern, in contrast to the granular, nonlattice structure of the slow tonic Z-line. The volume percentage sarcotubular system of the slow-twitch fibers was intermediate between and significantly different from that of the fast-twitch and slow tonic fibers. These correlative analyses suggest that the avian muscles contain not only the fast-twitch and slow tonic fibers previously known, but also a slow-twitch fiber that appears to be intermediate between the tonic and the mammalian slow-twitch fiber type. Based on the abundance of the sarcotubular system, this fiber type appears to be fast-contracting and -relaxing, in spite of being multiply innervated.
 ...
PMID:Quantitative ultrastructure of histochemically identified avian skeletal muscle fiber types. 361 80


1 2 3 4 Next >>