Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sartorius muscles of the frog Rana pipiens were used to study the incidence of motor nerve sprouting in normal unoperated muscles, in experimental muscles contralateral to axotomy of the sartorius nerve, and in sham-operated control muscles. Muscles were stained with either a combination of nitroblue tetrazolium nerve terminal stain and cholinesterase stain or with a combination of silver nerve terminal stain and cholinesterase stain. Each endplate that could be clearly seen was classified into one or more of the following categories: normal endplates without sprouts, three types of terminal sprouts, preterminal sprouts, nodal sprouts, sprouts of unknown origin and destination, and doubly innervated gutters. A quantitative study of 318 endplates from nine unoperated muscles, 779 endplates from 45 experimental muscles, and 694 endplates from 41 control muscles showed that all muscles had a high incidence of motor nerve sprouting and other forms of remodelling (20-28% of all endplates). There were, however, no significant differences between experimental, control, and unoperated muscles when results obtained with the same stains were compared. Results obtained with the two different stains were only slightly different. We conclude that sprouting is a very common but highly variable feature of normal frog neuromuscular junctions, and in the sartorius, contralateral axotomy does not alter this ongoing remodelling.
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PMID:Motor axon sprouting in frog sartorius muscles is not altered by contralateral axotomy. 387 65

Acetylcholinesterase (AChE; EC 3.1.1.7) extracted in 1% Triton X-100 from rabbit brain was purified 2,000-fold by chromatography on agarose conjugated with a monoclonal antibody directed against human red blood cell cholinesterase. After elution from the immunoadsorbent with pH 11 buffer, the preparation was purified further by affinity chromatography on phenyltrimethylammonium-Sepharose 4B with decamethonium elution. Overall yield of purified enzyme was 37% of the AChE originally solubilized, with a specific activity of 2,950 units/mg protein. Electrophoresis under reducing conditions in 7.5% sodium dodecyl sulfate polyacrylamide gels revealed only one silver-staining polypeptide band. A streamlined purification procedure enabled the isolation of electrophoretically homogeneous AChE to be completed in fewer than 7 days, at yields exceeding 50%. Electrophoretic analysis of purified AChE indicated an apparent MW of 71,000 for the monomeric subunit. Gel filtration and sucrose density gradient centrifugation in the presence of Triton X-100 showed little difference between the properties of the native and the purified enzyme. The molecular mass of the main species was estimated from the gel filtration and sedimentation data to be 280,000 daltons. Kinetic parameters of the purified protein (Km = 0.16 +/- 0.01 mM) were close to those of the native enzyme (Km = 0.12 +/- 0.01 mM) when examined with acetylthiocholine iodide as substrate. The two-step immunopurification procedure presented in this communication offers a convenient route to homogeneous neural AChE in quantities useful for detailed biochemical and immunochemical study.
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PMID:Two-step immunoaffinity purification of acetylcholinesterase from rabbit brain. 396 30

The patterns of sprouting of motor endplates were examined in fast extensor digitorum longus and slow soleus muscles and in tibialis anterior muscles containing fast and slow muscle fiber types. A histochemical technique combining nerve silver impregnation and endplate cholinesterase staining was developed for this task. Temporal examination of the innervation was conducted 3, 7 and 10 days after either a 45 or 90 min application of the ipsilateral sciatic nerve with 5 mM colchicine. This dosage of drug did not cause detectable axon or muscle fiber degeneration, unlike 60 mM which was highly neurotoxic. At 3 days following treatment with the lower concentration, there were no significant differences in the percentages of intranodal, preterminal and ultraterminal sprouts between the normal (non-treated), sham-treated, contralateral systemic-control and drug-treated groups of muscles. By 7 and 10 days, the muscles on the drug-treated side exhibited significant increases in the 3 types of sprouts. Collateral sprouting was uncommon: most outgrowths remained on the muscle fibers innervated by the parent axons. Endplates in the tibialis anterior muscles of the control and drug-treated groups were classified Complex, Intermediate or Simple according to the relative degrees of branching of the terminal arbors. The occurrence of endplate classes and muscle fiber types was correlated in the superficial and deep regions of this muscle. Complex endplates innervated fast glycolytic fibers, Intermediate endplates supplied fast oxidative glycolytic fibers, and Simple endplates served slow oxidative fibers. In response to colchicine, the endplates of the slow muscles sprouted more than those of fast muscles while the innervation of slow fiber types sprouted less than that of fast fiber types. Furthermore, intranodal sprouts were more prevalent in slow muscles and ultraterminal sprouts more numerous in fast muscles whereas intranodal sprouts predominated on fast fiber types and ultraterminal sprouts were characteristic of slow fiber types. These apparently contradictory results were reconciled when it was noted that soleus endplates were mostly Complex and Intermediate, and the extensor digitorum longus contained more Simple endplates. Thus, consistency of sprouting patterns among endplate types of the 3 muscles was recognized when the pre-existing branching patterns were considered. This indicated that the patterns of sprouting were determined by the motor neurons rather than the muscle fibers. The observed sprouting responses supported the hypothesis that colchicine treatment of motor axons caused muscle fibers to elaborate a diffusible sprout-inducing factor.
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PMID:Colchicine-induced differential sprouting of the endplates on fast and slow muscle fibers in rat extensor digitorum longus, soleus and tibialis anterior muscles. 397 64

The pattern of innervation to intact peroneal and extensor digitorum longus muscles of normal and experimental young adult mice was studied by light microscopy after staining neuromuscular junctions by a combined silver-cholinesterase stain. Spontaneous sprouting and synapse formation occur in intact muscles of normal mice. In about 7% of the junctions, sprouts contribute to the innervation of muscle fibres already innervated by their parent axons. Axotomy of the sciatic nerve in one hind limb is followed by an average 3-fold increase over normal in the incidence of sprouting and synapse formation in the intact muscles of the opposite hind limb. The time to onset of sprouting and synapse formation becomes shorter as the site of the contralateral axotomy is placed closer to the spinal cord. A significant increase over normal in the incidence of sprouting is first observed 5 days after a proximal sciatic nerve cut and only 12 days after a distal sciatic nerve cut. The timing of sprouting is independent of the difference in the number of axons that are involved in the contralateral axotomies at different sites. These findings suggest that, in the intact muscles of normal mice, sprouting and synapse formation is an ongoing process which can be enhanced by contralateral axotomy. As in frogs (Rotshenker, 1979, 1982) the underlying mechanism may be the transneuronal induction of sprouting and synapse formation.
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PMID:The transneuronal induction of sprouting and synapse formation in intact mouse muscles. 398 20

The tibialis anterior and extensor digitorum longus muscles of the rat were reduced in size either by crushing the sciatic nerve or by removing part of the muscle tissue during the first postnatal week. Four to 6 weeks later the number and size of the motoneurones supplying these muscles were assessed using retrograde transport of horseradish peroxidase. The pattern of synaptic connections in the muscles supplied by these motoneurones was examined 3-46 weeks after the initial operation using a combined silver cholinesterase stain. The number of labelled motoneurones was not reduced after nerve crush but was reduced to some extent after partial muscle removal. The distribution of motoneurone sizes, however, was altered by both procedures in that the largest motoneurones became smaller. In the muscle both procedures affected synaptic organization. In the case of sciatic nerve crush at 5-6 days the incidence of muscle fibres with more than one endplate and endplates contacted by more than one axon terminal was higher than in normal adult muscles. When part of the muscle was removed, the predominant feature was the persistence of a high incidence of free sprouting nerve fibres. We therefore conclude that reduction of the peripheral field during the postnatal period does affect the development of some motoneurones.
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PMID:The effect of reducing the peripheral field on motoneurone development in the rat. 399 31

The regeneration of fast and slow muscles was compared following "mincing" and replacement into their own or alien muscle bed. At intervals varying from 2 to 9 weeks the tension developed by the regenerated muscles was assessed and compared to that developed by the muscles from the contralateral unoperated side. This parameter was then taken as an indication of recovery. The regenerated muscles never developed more than half of the tension of the control muscles. Muscles regenerated in the bed of extensor digitorum longus became fast-twitch muscles and muscles regenerated in the bed of soleus became slow-twitch muscles, no matter whether they originated from an extensor digitorum longus or soleus "mince". The regeneration of the muscle tissue in the place of extensor digitorum longus developed better than in the place of soleus. The pattern of innervation of the regenerated muscles was analysed using a combined cholinesterase silver stain. Many of the regenerated fibres had more than one end plate and some end plates more than one axon terminal. These results show that in adult animals muscle redevelopment can occur, but only to a limited extent. Moreover, on reinnervation of regenerated muscle fibres the axons do not assume their original pattern of innervation.
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PMID:Physiological properties and pattern of innervation of regenerated muscles in the rat. 402 36

1. The hemidiaphragm of the adult rabbit has a single band of end-plates running around the middle of the muscle. A study has been made of the formation of synapses during spontaneous reinnervation of this muscle, using histological, ultrastructural and electrophysiological techniques.2. Following spontaneous reinnervation, silver-stained nerve terminals were found in association with cholinesterase-stained end-plates only in the region of the muscle corresponding to the original innervation band.3. The regenerated nerve terminals were observed with the electronmicroscope in positions overlying or adjacent to the old synaptic folds.4. Spontaneous miniature end-plate potentials and evoked synaptic potentials were recorded only in the middle of the muscle fibres after reinnervation.5. The growth of the regenerating axons was not oriented towards the end-plate zone but followed muscle fibres and blood vessels in random directions.6. It is concluded that, in adult mammalian striated muscle, the old end-plate region is preferentially reinnervated as a consequence of some special property of the muscle fibre at this site.
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PMID:The formation of synapses in reinnervated mammalian striated muscle. 412 28

1. A study has been made of the formation of synapses during reinnervation of the hemidiaphragm of adult rabbits with preganglionic fibres of the thoracic vagus, using histological, ultrastructural and electrophysiological techniques.2. Following reinnervation with preganglionic axons, silver-stained nerve terminals were found in association with cholinesterase-stained end-plates only in the region of the muscle corresponding to the original innervation band.3. The fine preganglionic axons retained their normal structure in striated muscle, but were found to synapse over discrete areas of dimensions not larger than those of the original end-plates.4. The regenerated varicose preganglionic nerve terminals were observed with the electronmicroscope in positions either overlying or in the vicinity of the old synaptic folds.5. Spontaneous potentials and evoked synaptic potentials were recorded only in the middle of the muscle fibres after vagus reinnervation.6. In a few cases, multiple synaptic potentials with similar time courses were recorded, suggesting that several axons had formed synapses at a single site on a muscle fibre.7. It has been shown that, during reinnervation of adult mammalian striated muscle fibres with nerves other than those of the somatic system, synapses are formed preferentially in the region of the old end-plates.
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PMID:The formation of synapses in mammalian striated muscle reinnervated with autonomic preganglionic nerves. 412 29

Both the neural and subneural components of mammalian peripheral motor endings in teased preparations have been shown by a new method which combines a silver method with a cholinesterase technique. The significant application of this method to the study of the motor terminals is suggested.
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PMID:A combined method for demonstrating the cholinesterase activity and the nervous structure of mammalian peripheral motor endings in teased preparations. 605 2

Choline acetyltransferase (ChAc) was localized at the neuromuscular junctions of rabbit diaphragm with immunohistochemical staining, which produced a brown color, in combination with histochemical staining for cholinesterase, which produced a blue color, in the same section. The innervations of nerve terminals at the neuromuscular junctions were comparable when a silver impregnation was substituted for the immunohistochemical staining of ChAc.
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PMID:Localization of choline acetyltransferase at neuromuscular junctions. 616 79


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