Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is demonstrated by experiments with rabbits that the Ca2+-ATP-ase activity is stabilized when using combined anesthetics (diacetylcholine + halothane + N2O) as distinct from application of halothane. A decrease in the cholinesterase activity is less pronounced than under the halothane action but more than with the diacetylcholine application. A decrease in the Na+, K+-ATP-ase activity is observed with all types of anesthesia. A considerable inhibition of creatine kinase under the action of combined anesthesia and halothane and an increase of the lactate dehydrogenase activity under diacetylcholine application in mitochondria are shown. Reliable differences in the succinic dehydrogenase activity are not detected.
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PMID:[Effect of combined anesthetics on the activity of various myocardium enzymes]. 303 46

Two main groups of quantitative methods are used in the brain to relate enzymatic processes to cellular structures, i.e. the methods of microchemistry and microscopic histochemistry. Microchemistry tries to quantify enzyme activities in very small brain regions by miniaturizing biochemical methods, whereas microscopic histochemistry applies staining procedures to tissue sections, preserving the structural relationship that is present in situ and giving topological information on the distribution of enzymes which is indispensable in structural heterogeneous tissue as is the brain. The present review deals preferentially with microscopic methods and, in particular, with scanning microphotometry (image plane scanning). Using this technique two measuring procedures can be applied for the quantification of enzyme activities, i.e. end-point and kinetic (continuous monitoring) measurements which are described in detail. Methods for the microphotometric demonstration of certain important dehydrogenases (isocitrate dehydrogenases, succinate dehydrogenase, NAD-linked malate dehydrogenase, glutamate dehydrogenase and glycerol 3-phosphate dehydrogenase), of cytochrome c oxidase, hexokinase and acetylcholinesterase are presented. These methods were adapted for giving optimal demonstration of enzyme activities in the rat hippocampus. The examples are given to illustrate the aptitude and possibilities of this technique in the quantification of enzymes in the complex matrix of the brain.
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PMID:Quantitative enzyme histochemistry in the brain. 306 15

We have studied the lateral rectus muscles and neuromuscular junctions (NMJs) of abducens motoneurons in wobbler (wr/wr) mutant mice from 26 to 58 days of age. The muscles of wr/wr weighed about 70% of the weight of littermate controls and were composed of fiber types comparable to those of controls, as assayed by succinate dehydrogenase activity. The most obvious difference between wr/wr and control NMJs was a reduction in the length of the postjunctional membrane of wr/wr mice. The mutant muscle endplate membrane was only about 70% (6.58 micron) the length of control muscle regions (9.44 micron). There were no obvious differences at the light microscopic level in the distribution of acetylcholine (ACh) receptors at junctional regions or staining of acetylcholinesterase, as assayed with alpha-bungarotoxin binding or enzyme histochemistry. Indirect immunocytochemical studies using antibodies directed against the subunits of the ACh receptor failed to indicate an abnormal presence of immature receptors clustered at the NMJs of wr/wr mice. Our findings suggest that the formation or maintenance of normal postjunctional folds and the differentiation of receptors at the junctions are under independent control during development. Furthermore, the wobbler mutation may affect muscle cell differentiation as well as neuronal differentiation. This mutant mouse should prove a useful model for study of postjunctional fold formation and function.
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PMID:Abnormal neuromuscular junctions in the lateral rectus muscle of wobbler mice. 319 13

Architectural characteristics of the thalamus in echidnas and rats were compared in sections stained to reveal cell bodies, myelin, acetylcholinesterase, succinate dehydrogenase and cytochrome oxidase. Numerous species differences were noticed: in general, the thalamus is architecturally more homogeneous in echidnas than in rats, especially anteriorly. In this report we emphasize the presence of a relatively large structure localized in the anteromediodorsal part of the thalamus in echidnas. This structure, previously shown to project to the frontal cortex, contains very small amounts of acetylcholinesterase and the oxidative enzymes; in this respect it resembles the mediodorsal nucleus of rats. The same properties make this formation different from the anterodorsal and anteroventral nuclei in rats, the equivalents of which could not be identified in echidnas. The anteromediodorsal region of the thalamus in echidnas consists chiefly of two cytoarchitecturally different regions: the medial, 'polymorphic' part contains relatively small, densely packed, multiform perikarya, whereas the lateral, 'monomorphic' part is characterised by larger, sparse neurons with little cytoplasm and round, large, empty-looking nuclei in which the nucleolus is clearly seen. We conclude tentatively that this brain structure of echidnas corresponds to the mediodorsal nucleus in placental species. Further studies of connections and chemical properties will be essential to determine the degree of correspondence of the presumed 'frontal lobe system' in echidnas to that in other mammals.
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PMID:Architectonics of the thalamus in the echidna (Tachyglossus aculeatus): search for the mediodorsal nucleus. 342 11

A procedure is described for the rapid preparation of nerve ending particles (synaptosomes) from 11 regions of one rat brain. The synaptosomal fractions have been characterized by electron microscopy and determination of four marker enzymes, i.e., glutamate decarboxylase (GAD), acetylcholinesterase, succinate dehydrogenase, and glycerol 3-phosphate dehydrogenase. Comparison with a much lengthier standard (Ficoll-sucrose) preparation showed that the synaptosomal yield of the new procedure was substantially better as judged by both morphological evaluation and protein recovery. The improved synaptosome preparation was used for determination of regional gamma-aminobutyric acid (GABA) levels in synaptosomal fractions. The postmortem increase in GABA level during removal and dissection of brain tissue and homogenization and fractionation procedures could be minimized by rapid processing of the tissue at low temperatures and inclusion of the GAD inhibitor 3-mercaptopropionic acid (3-MP; 1 mM) in the homogenizing medium. The addition of GABA (0.2 mM) to the homogenizing medium did not alter the GABA levels in the synaptosomes, indicating that no significant redistribution of GABA occurred during subcellular fractionation in sodium-free media. Synaptosomal GABA levels determined in the 11 rat brain areas showed the same regional distribution as the GABA-synthesizing enzyme GAD. On the basis of these findings, it was suggested that the synaptosome preparation could be used to evaluate the in vivo effects of drugs on nerve terminal GABA. Treatment of rats with a convulsant dose of 3-MP (50 mg/kg i.p.) 3 min before decapitation significantly lowered synaptosomal GABA levels in olfactory bulb, hippocampus, thalamus, tectum, and cerebellum. The 3-MP-induced seizures and reduction of GABA levels could be prevented by administration of valproic acid (200 mg/kg i.p.) 15 min before the 3-MP injection. The data indicate that the improved synaptosome preparation offers a convenient method of preparing highly purified synaptosomes from a large number of small tissue samples and can provide useful information on the in vivo effects of drugs on regional GABA levels in nerve terminals.
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PMID:Improved method for isolating synaptosomes from 11 regions of one rat brain: electron microscopic and biochemical characterization and use in the study of drug effects on nerve terminal gamma-aminobutyric acid in vivo. 392 10

Male Wistar rats exposed to 50, 100 or 300 ppm methyl tertiary-butyl ether vapour for 2-15 weeks, 6 h daily, 5 days a week, showed a dose-dependent blood ether concentration after 2 weeks' exposure. Blood concentrations of tertiary-butanol, were also dose dependent indicating metabolic breakdown of the ether in vivo. The blood ether concentrations decreased after 6 weeks of exposure at the 50 ppm dose level and remained unaffected at higher doses while tertiary-butanol concentrations increased after 6 weeks with all doses, and began to decrease thereafter. Exposure caused a transient increase in UDP-glucuronosyltransferase activities in liver and kidney microsomes, almost no effects on hepatic cytochrome P-450 concentrations and a minor induction of kidney microsomal cytochrome P-450 content. Exposure produced almost no effect on brain succinate dehydrogenase, creatine kinase or acetylcholinesterase activities, while early inhibition of muscle creatine kinase activity was noted, accompanied by increased activity at the end of exposure.
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PMID:Biochemical effects of methyl tertiary-butyl ether in extended vapour exposure of rats. 409 53

Hydroxylamine chloride (0.3 g/l) in drinking water was given to 3-mo-old male Wistar rats for 1 to 63 days. The treatment caused splenomegalia while no effect was noted on the weight gain. Cerebral RNA content was also unaffected whereas slight decrease in the cerebral homogenate and isolated glial cell succinate dehydrogenase activities was found. Creatine kinase activity in the glial cell fractions increased after 63 days. An initial increase in the muscle acetylcholinesterase activity resolved in muscle after 2 wks while increased muscle creatine kinase activity was found throughout the experiment. The splenomegalia might have been caused by methemoglobinemic red cell fragility, an established NH2OH effect, while the neurochemical effects and effects on muscle might have resulted from direct toxicity rather than from the relative hypoxia because of impaired oxygen transport capacity.
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PMID:Neurochemical effects of ingested hydroxylamine. 608 90

Tench (Tinca tinca) were acclimated to either aerated (P02 17.6 KPa) or hypoxic water (P02 1.5 KPa) at 15 degrees C. Fish acclimated to P02 17.6 KPa had a routine oxygen consumption (mls O2/Kg bodyweight/h) of 32.7 in aerated water. Upon acute exposure to Po2 1.5 KPa oxygen consumption decreased to 10.8 and 15.6 in fish acclimated to aerated and hypoxic water, respectively. On the basis of staining for glycogen and for the activities of myofibrillar ATPase and succinic dehydrogenase, three main fibre types can be differentiated in the myotomal muscle. Fibres have been classified as slow, fast aerobic and fast glycolytic. Fast aerobic fibres can be distinguished histochemically by their alkaline-stable Ca2+-activated myofibrillar ATPase activity and their intermediate levels of staining for glycogen and succinic dehydrogenase activity. The patterns of innervation of the fibre types have been investigated by staining neuromuscular endplates and peripheral axons for acetylcholinesterase activity. Motor axons to slow fibres branch extensively giving rise to a number of diffuse endplate formations on the same and adjacent fibres. Fast glycolytic fibres also have a complex pattern of innervation with 8-20 endplates per fibre. A large proportion of the endplates belonged to separate axons. Cross-sectional areas and perimeters of fibres, the number of capillaries/fibre and the lengths of contacts between capillaries and fibres were determined from low-magnification electron micrographs. Acclimation to hypoxia resulted in a decrease in the number of capillaries per fibre for both slow (1.8 to 1.0) and fast (0.8 to 0.2) muscles. The capillary perimeter supplying 1 micrometer 2 of fibre cross-sectional area decreased by 43% and 76% for slow and fast fibres, respectively.
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PMID:Routine oxygen consumption and characteristics of the myotomal muscle in tench: effects of long-term acclimation to hypoxia. 621 53

Involvement of phosphate-activated glutaminase in Huntington's disease and agonal state was investigated in caudate nucleus and frontal cortex from postmortem brains. In Huntington's disease the activities of phosphate-activated glutaminase, glutamic acid decarboxylase, succinic dehydrogenase, choline acetyltransferase, and acetylcholinesterase were significantly reduced in the caudate nucleus, but not in the frontal cortex. The activity of phosphate-activated glutaminase, and to a lesser extent of glutamic acid decarboxylase, was reduced in cases of terminal illness, as compared with cases of sudden death. Succinic dehydrogenase and choline acetyltransferase were reduced only in the few cases of prolonged and severe terminal illness. Enzyme activities of the caudate nucleus were more affected by agonal state than were those of frontal cortex. Results indicate that phosphate-activated glutaminase could be a useful marker of neuronal damage due to agonal state, and that phosphate-activated glutaminase and succinic dehydrogenase are reduced in Huntington's disease.
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PMID:Phosphate-activated glutaminase in relation to Huntington's disease and agonal state. 622 89

The muscle fibers of the cranial slip of M. pectoralis pars thoracica of an emu (Dromaius novaehollandiae) were studied histochemically for intracellular lipid, succinic dehydrogenase, myofibrillar adenosine triphosphatase, and acetylcholinesterase. It was concluded that the muscle consisted of approximately 28% slow-tonic and 72% fast-twitch glycolytic fibers. The tonic fibers were considered to be characteristic of a postural muscle, and the fast-twitch glycolytic fibers to reflect the inability of the muscle to engage in sustained activity. The general absence of slow-tonic fibers from the pectoralis of other avian species so far studied may be attributed to inadequate sampling of the deeper regions of the muscle.
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PMID:Some histochemical properties of the fiber types in the pectoralis muscle of an emu (Dromaius novaehollandiae). 623 56


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