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)

The fast-twitch posterior latissimus dorsi muscle of normal and genetically dystrophic chickens was subjected to continuous indirect electrical stimulation at 10 Hz for periods of 4-8 weeks. To sustain this in vivo nerve stimulation an internally implantable miniature stimulator device was designed. This regime of stimulation caused complete fatigue of the normal muscle within 5 min of its initiation. The dystrophic muscles maintained a very small degree of contractile activity during this initial phase. Tangible twitching of the muscle returned in 5 week birds between 3 and 5 days and in 10 week birds between 11 and 16 days after implantation. After 4 weeks of stimulation, no significant change was measured in the time-to-peak of the isometric twitch response, nor in the half-relaxation time. The resistance to fatigue was significantly increased in the stimulated muscles when tested with a series of tetani at 40 Hz. The mean fibre area was decreased, in all muscles stimulated for longer than 3 weeks, in comparison to their contralateral controls, except where fibre splitting in dystrophic birds abnormally reduced the control value. The majority fibre type of the muscle was changed from type IIB to IIA. The histochemical reactions for both NADH-linked oxidation and phosphorylase were distinctly increased in the stimulated muscles. In normal muscle, stimulation increased somewhat the number of nuclei per unit area and changed their intracellular distribution, so that a greater proportion was found adjacent to the sarcolemma. The normal posterior latissimus dorsi muscle responded to chronic stimulation with increases of 3-6-fold in its acetylcholinesterase (AChE) activity. The maximum change in AChE occurred after 2 weeks stimulation; a steady level, 3 times that of the control unstimulated muscle, persisted at later times. Chronic stimulation suppressed the over-production of AChE that is characteristic of dystrophic chicken fast-twitch muscle, to attain a level comparable to the AChE activity in a stimulated normal muscle. Stimulation exerted a strong normalizing influence on dystrophic muscle, as assessed morphologically. The characteristic fibre rounding, fibre hypertrophy and myonuclear proliferation were reduced. This influence was most marked where the stimulation was initiated before the major pathological changes had occurred, but was also significant when commenced in strongly affected birds of 10-11 weeks.
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PMID:Low frequency chronic electrical stimulation of normal and dystrophic chicken muscle. 379 78

An enzymatic method for the determination of serum cholinesterase (ChE) activity is described. The method is based on the liberation of acetate from acetylcholine as a substrate by ChE and the conversion of the acetate to acetylphosphate and ADP in the presence of ATP by acetate kinase. The produced ADP is coupled with pyruvate kinase and lactate dehydrogenase in the presence of phosphoenolpyruvate and NADH. The amount of NADH consumed is determined by absorbance at 340 nm. The reaction proceeds stoichiometrically, and the dilution curve is linear up to 3300 U/liter. The results obtained by this method show a good correlation with those obtained by the usual methods.
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PMID:Ultraviolet spectrophotometric method for determination of cholinesterase activity with acetylcholine as a substrate. 409 50

Cat muscle spindles were studied histochemically in serial transverse sections of the tenuissimus muscle stained for myofibrillar ATPase, cholinesterase or NADH-tetrazolium reductase. The terminal sites of the primary and secondary axons on intrafusal muscle fibers could be demonstrated due to their high NADH-TR activity. This sensory NADH-TR reactivity at the equator and in the juxtaequatorial regions disappeared following spindle chronic de-afferentation, but not after de-efferentation. Spindle poles that carried both primary and secondary sensory endings had a longer periaxial fluid space than poles with primary endings only, and their motor innervation, as determined by staining for ChE, was positioned at the greater distance from the equator. Some of the secondary endings occurred in intrafusal regions that displayed surface fiber ChE activity. The histochemical reaction for NADH-TR represents a simple, rapid and reliable method for studies of the distribution of sensory nerve terminals in the spindle.
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PMID:Appearance of sensory nerve terminals in cat muscle spindles stained for NADH-tetrazolium reductase. 617 8

Enzyme histological changes have been studied in several optic projection areas after right optic nerve lesion in goldfish. An increase in acid phosphatase activity was found in the optic tectum, nucleus rotundus, nucleus geniculatus lateralis and area pretectalis between 2 and 15 days postoperatively. The enzymes glutamate dehydrogenase, lactate dehydrogenase, NADH tetrazolium reductase, cytochrome oxidase, succinate dehydrogenase and beta-hydroxybutyrate dehydrogenase showed a decrease in activity in all or some of these projection areas. No changes were found in acetylcholinesterase activity after optic nerve lesions. Three weeks postoperatively, all enzyme activities returned to the same level as on the normal side. The results are discussed in relation to possible neurotransmitters in goldfish optic terminals.
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PMID:Enzyme histochemical changes in some optic projection areas of the goldfish after optic nerve lesions. 626 19

Muscle spindles were examined histochemically in serial transverse sections of cat tenuissimus muscles. The myofibrillar adenosine triphosphatase (ATPase) staining reaction was used to identify nuclear bag1, bag2 and nuclear chain intrafusal muscle fibers. Regional differences in ATPase staining occurred along the bag1 and bag2 fibers but not along the chain fibers. All intrafusal fiber types displayed regional variability in staining for nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR). Motor nerve terminals were demonstrated along the poles of bag1, bag2 and chain fibers by staining for cholinesterase (ChE). There was no consistent spatial correlation between the intensity of regional ATPase staining along the bag fibers and location, number or type of motor endings. However, most ChE deposits occurred in intrafusal fiber regions that displayed the greatest NADH-TR variability. Some fiber poles or whole intrafusal fibers were devoid of any ChE deposits but their ATPase and NADH-TR content was comparable to that of fibers bearing ChE deposits. The observations suggested that motor nerve fibers per se may not play a major role in determining the histoenzymatic content of intrafusal fibers.
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PMID:Histochemical profiles of cat intrafusal muscle fibers and their motor innervation. 646 12

Incubation of washed rabbit platelets with suspensions of dilauroylglycerophosphocholine resulted in the shedding of vesicles without causing any appreciable leakage of cytoplasmic marker (lactate dehydrogenase) or organelle marker [( 14C]serotonin). The response was dependent on incubation time, concentration of dilauroylglycerophosphocholine and reaction temperature. Vesicles were separated from platelets and exogenous dilauroylglycerophosphocholine by a series of centrifugation steps. An average diameter of vesicles was 100-200 nm on scanning electron microscopy. Vesicles were enriched 5-fold in plasma membrane marker enzyme, acetylcholinesterase, whereas specific activities of lactate dehydrogenase and intracellular membrane marker enzyme, NADH-cytochrome c reductase were decreased in vesicles. Protein analysis by SDS-polyacrylamide gel electrophoresis showed that actin and actin-binding protein were present, while myosin was barely detectable in vesicles. Vesicles contained all phospholipid species of intact platelets and cholesterol but almost 50% of phospholipids in vesicles was dilauroylglycerophosphocholine. The phospholipid to protein ratio in vesicles was about 6.5-times higher than in intact platelets.
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PMID:Vesiculation of platelet plasma membranes. Dilauroylglycerophosphocholine-induced shedding of a platelet plasma membrane fraction enriched in acetylcholinesterase activity. 649 86

To examine the morphological sequence of regenerating fibers after myonecrosis in dystrophic muscles, 0.5 ml of 0.5% bupivacaine hydrochloride (BPVC) (Marcaine) solution, a local anesthetic with a cytotoxic effect on the muscle fibers, was injected directly into the dystrophic (line 413) and nondystrophic (line 412) posterior latissimus dorsi (PLD) muscles of young and adult chickens. Although the dystrophic muscles after BPVC injection showed a rapid recovery with a similar tempo to that of nondystrophic ones, they showed different morphological behavior in the early phase of regeneration, including marked variability in the size of fibers and in the intracytoplasmic enzyme activities of nicotinamide adenine dinucleotide, reduced-tetrazolium reductase (NADH-TR), acetylcholinesterase (AChE), and nonspecific esterase (NSE).
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PMID:Regenerative capability of skeletal muscle in chicken muscular dystrophy. 673 79

Polymorphonuclear leucocytes were isolated from pig blood relatively free from other cells and were characterised biochemically and morphologically and compared with human PMNLs. The activities of 16 enzymes of porcine and human PMNLs were measured and compared. Alkaline phosphatase, acid phosphatase, phosphodiesterase, gamma-glutamyl transpeptidase, NADH-cytochrome c oxidoreductase, malate dehydrogenase and acetylcholinesterase had higher specific activities in procine than in human cells. Alkaline phosphatase has an 87-fold higher specific activity in porcine than in human cells. beta-glucuronidase, lysozyme, beta-galactosidase, N-acetyl-glucosaminidase, beta-glucosidase, myeloperoxidase and catalase had higher specific activities in human than in porcine cells. beta-glucuronidase and myeloperoxidase showed over a 1000- and a 13-fold higher specific activity, respectively, in human than in porcine cells. Porcine PMNLs are readily available in large numbers and are recommended for studies of phagocytosis, chemotaxis and membrane biochemistry.
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PMID:Biochemical characterisation of porcine polymorphonuclear leucocytes: comparison with human polymorphonuclear leucocytes. 687 22

Coated and noncoated vesicles participate in cellular protein transport. Both acetylcholine receptors (AChR) and acetylcholinesterase (AChE) are transported via coated vesicles, some of which accumulate beneath the neuromuscular synapse where AChRs cluster. To investigate the mechanisms by which these proteins are transported during postsynaptic remodeling, we purified coated vesicles from the bovine brain via column chromatography (Sephacryl S-1000) and raised monoclonal antibodies to epitopes of the vesicular membranes enriched in AChE. We assayed for AChE (coated vesicle enriched), hexosaminidase (lysosomal contaminants), NADH cytochrome C reductase (mitochondrial containing), and protein and demonstrated electron microscopically using negative staining that the vesicular fraction contained 95% pure coated vesicles. We then injected coated vesicle fractions and the fractions from which the coat was removed intraperitoneally into mice and obtained three monoclonal antibodies: C-33, C-172, and F-22. On immunoblots of purified vesicles and cultured skeletal muscle, mAb C-33 stained a 180 Kd band and mAb C-172 stained a 100 kd band. MAb F-22 stained 50 kd and 55 kd bands and was not characterized further. Immunofluorescent microscopy with C-33 and C-172 revealed punctate fluorescence whose distribution depends upon the stage of myotube development. Four days after plating, myotubes showed punctate fluorescence throughout the myotube, whereas those stained 8 days after plating showed a punctate perinuclear distribution. Myotubes innervated by ciliary neurons show punctate fluorescence limited to the nuclear periphery and most concentrated around nuclei which line up beneath neuronal processes. This differential vesicular distribution, observed during myotube differentiation and innervation, suggests that these vesicles participate in vesicular membrane traffic.
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PMID:Differential distribution of vesicular carriers during differentiation and synapse formation. 826 42

Arguments are presented in this commentary to show that the model of temperature-nearly-independent binding that we proposed to rationalize the binding characteristics of beta-adrenergic antagonists (Miklavc et al., Biochem Pharmacol 40: 663-669, 1990) in fact provides a consistent interpretation of the temperature-nearly-independent binding constant in all other systems that have been reported in the literature: in the binding of coenzyme NADH to horse liver alcohol dehydrogenase and to octopine dehydrogenase and in the binding of an inhibitor to acetylcholinesterase No such consistent interpretation has been given thus far for any of these systems. It is characteristic of them that the binding takes place in a hydrophobic, sterically constrained environment. One can assume, therefore, that the underlying entropy-driven binding mechanism would reflect the existence and the properties of the steric bottleneck surrounding the binding pocket. We also explain why the temperature effects characteristic of hydrophobic interactions are not found experimentally in these systems, whereas in other, sometimes even structurally similar, systems such temperature effects are clearly present. Further work in necessary to establish more firmly the key features of the temperature-nearly-independent binding mechanism that has been disclosed through our analysis. The binding mechanism in question not only appears in important biochemical systems, but also has the interesting property of being relative unaffected by smaller structural changes.
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PMID:Temperature-nearly-independent binding constant in several biochemical systems. The underlying entropy-driven binding mechanism and its practical significance. 860 66


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