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)

Previous reports from this laboratory have indicated that fetal rat striatal grafts have the major types of neuronal and glial components known to be involved in Huntington's chorea. In this study a number of major afferent and efferent innervations seen in normal striatum were examined in the striatal grafts and were compared with embryonic striatal afferents. First, using immunocytochemistry and histochemistry, the host serotonergic (5-HT), dopaminergic (DA, stained with anti-tyrosine hydroxylase (TH) antiserum), and acetylcholinesterase (AChE) fibers exhibited vigorous growth into the grafts implanted in neostriatum, lateral ventricle, globus pallidus or substantia nigra within a period of 6 and 10 weeks. Individual characteristic terminal patterns formed in striatal grafts: 5-HT fibers were diffused; TH fibers became heavily packed, and AChE fibers were patchy. This peculiar patternization of 5-HT and TH growth into striatal graft appeared to be a recapitulation of the normal 5-HT and TH ingrowth into striatum in the embryonic stage. However, a significantly slow (6 week) onset of adult 5-HT and TH ingrowth into the fetal graft was noted, as compared with that of normal embryonic development (5-6 days from the appearance of 5-HT and TH neurons). With the anterograde-transport marker Phaseolus vulgaris agglutinin leuca method, host cortical neurons also projected to the graft, but in limited numbers. Finally, with the retrograde-transport marker (horseradish peroxidase method, the grafts implanted in neostriatum were found incapable of sending fibers to a major, distal target, substantia nigra. In a current evaluation of striatal transplants, it is shown that major input to the graft can be achieved over time, but output to the distal nigra seems an unrealistic expectation. These data suggest that: (1) the fetal brain tissue was found to be a strong stimulant for sprouting or regeneration of adult nerve fibers; (2) a number of functional recoveries reported on the tested behavior paradigm in this grafting model could be due to the survival of striatal graft and the establishment of input circuitries; further, (3) the data illustrate the necessity of seeking a bridge from the striatal transplant to the host nigra. If a proper functional recovery in Huntington's chorea requires complete striatonigral circuitry, then such a bridge is worthy of a major investigation.
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PMID:Connectivities of the striatal grafts in adult rat brain: a rich afference and scant striatonigral efference. 259 10

A comparative study on the changes of the acetylcholinesterase activity (AChE) and of choline acetyltransferase (ChAT)- and GABA-like immunoreactivity (LI) has been performed in the ventral horn cells of the spinal cord of white rats 1, 2 and 3 weeks after transection of the right sciatic nerve. For the visualization of the AChE the method of Karnovsky and Roots (1964) was used. ChAT-LI was demonstrated by means of the avidin-biotin-peroxidase complex method (Hsu et al., 1981), whereas GABA-LI was localized using the PAP-method of Sternberger et al. (1970). In the control rats AChE-activity was observed on the cellular membrane, weaker in the cytoplasm of the perikarya and the proximal processes of the motoneurons; a pericellular localization of the reaction product was also established. ChAT-like immunoreactivity was mainly observed in the cytoplasm of the perikarya and the cellular processes, whereas GABA-like was most intensive in the nuclei of a number of motoneurons and in the more distal parts of their dendrites; the staining intensity of the perikaryal cytoplasm was weaker. During chromatolysis a progressive decrease of the staining intensity of the reactions for all the 3 substances was observed. In some neurons there was a total loss of the immunoreactivity. These results suggest that during chromatolysis: 1. the production of acetylcholine and GABA decreases; 2. the GABA which coexists within some cholinergic motoneurons may be expressed by these cells and 3. the AChE activity may also in the future be used as a marker of the cholinergic system of the anterior horn cells of the spinal cord.
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PMID:[Acetylcholinesterase activity, choline acetyltransferase and GABA immunoreactivity in the ventral horn of the spinal cord of rats during chromatolysis]. 264 82

Laboratory and clinical evidence of the inhibition of plasma cholinesterase by metoclopramide was demonstrated. When succinylcholine is used as the substrate and the product choline assayed by choline oxidase-peroxidase-quinone dye colorimetry, the rate of the choline production as optical density change was reduced to 50% by 19.5 X 10(-6) M metoclopramide at 20 degrees C. Prolongation of neuromuscular blockade produced by concurrent administration of succinylcholine and metoclopramide was studied in 22 patients aged between 18 and 40 years undergoing elective gynecological surgery. EMG activity in the adductor pollicis muscle was recorded in response to a train-of-four (TOF) stimulus delivered every 10 s. Patients were randomly divided into two groups: A and B. In both groups, anesthesia was induced with thiopental and maintained with sufentanil and nitrous oxide. Tracheal intubation followed intravenous succinylcholine. Intraoperatively, after returning of neuromuscular function, patients in both groups received 20 mg succinylcholine for the determination of duration of neuromuscular blockade. Time from 95% suppression of baseline twitch following a 20 mg increment of succinylcholine until recovery to 25% of control activity was determined. Thereafter, in group A, patients receive metoclopramide (10 mg iv) followed by succinylcholine 20 mg iv, and patients in group B received succinylcholine 20 mg iv alone. Recovery times were again measured and found to be prolonged in patients receiving metoclopramide compared with those not receiving metoclopramide (P less than 0.05). Metoclopramide has no intrinsic neuromuscular blocking activity, but its ability to inhibit plasma cholinesterase probably is the mechanism by which it prolongs succinylcholine block. Reducing the dose of succinylcholine may be appropriate when metoclopramide is given concurrently.
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PMID:Prolongation of succinylcholine block by metoclopramide. 265 89

Geniculo-recipient layers of primary visual cortex in the rat display a transient pattern of acetylcholinesterase (AChE) activity during the second postnatal week of life. Previous work has demonstrated that neonatal enucleations markedly reduce the transient AChE activity in visual cortex. The present studies were undertaken to determine the effects of reduced afferent neural activity on expression of the transient pattern of AChE activity. Rat pups received intraocular injections of tetrodotoxin (TTX) on postnatal days (PND) 3, 5, 7, 9 and 11 and were sacrificed on PND 12. Some animals were enucleated on PND 3. Brain sections were processed for AChE histochemistry and analyzed by optical densitometry. These experiments show that uniocular injections result in a markedly decreased level of AChE activity in layer IV of the medial part of cortical area 17 contralateral to the injected eye. The degree of reduction of AChE activity from repeated TTX injections was similar to the degree of reduction following enucleation on PND 3. Binocular injections of TTX result in a reduction of AChE activity in layer IV throughout cortical area 17, similar to the effects of binocular enucleation on PND 3. Experiments combining injection of horseradish peroxidase along with TTX on PND 11 demonstrate that retinal ganglion cells of TTX injected eyes are still capable of anterograde axonal transport. These data demonstrate that normal innervation and afferent activity are necessary for the transient expression of AChE activity by geniculocortical neurons.
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PMID:Intraocular injections of tetrodotoxin reduce transiently expressed acetylcholinesterase activity in developing rat visual cortex. 270 72

Embryonic neural tissues were taken from the ventral mesencephalon, the striatal anlage, the cerebellum, or the dorsal telencephalon. Prior to grafting these tissues were dissociated. This provided the opportunity to generate experimental cografts and allowed the introduction of neuronal tracers. Projections from grafts that contained dopaminergic neurons of the mesencephalon were identified immunocytochemically with antisera to tyrosine hydroxylase. Acetylcholinesterase histochemistry was employed to both stain the graft and to visualize graft efferent fibers. Moreover, dissociated tissues, with the exception of the ventral mesencephalon, were treated in vitro with rhodamine-conjugated microspheres. The immature cells incorporated the tracer in vitro. Labeled grafts were placed adjacent to large fiber tracts of the recipient brain or into the lateral ventricle and grown for one to two months. Different types of neurons within the grafts retained the rhodamine tracer. Some of the labeled neurons were positive for acetylcholinesterase. Efferent fibers from the different neural grafts followed similar routes within the host brain. Fibers containing microspheres projected commonly along the nearest host pathway or the labeled fibers followed the reactive glia along the original stab wound. Grafts that were located within the lateral ventricle projected their efferent fibers adjacent to the ventricular surface. Similar routes were followed by efferent fibers from transplanted dopaminergic neurons. One of the projection routes along the hosts corpus callosum was confirmed by horseradish peroxidase tracer transport. We conclude that elongation of graft pathways may occur along existing fiber tracts of the host brain, near structures of the ventricular surface, and alongside glia scars of a graft placement tract.
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PMID:Neo-pathway formation of dissociated neural grafts demonstrated by immunocytochemistry, fluorescent microspheres, and retrograde transport. 273 Oct 44

Acetylcholinesterase staining on successive frontal or sagittal sections was used to determine the three-dimensional organization of the striosomal and matrix compartments in the adult cat caudate nucleus. Reconstruction drawings of the acetylcholinesterase-poor zones (striosomes) indicated that the striosomal compartment is a labyrinthine network organized in the rostrocaudal and mediolateral axis which is reproducible from one animal to another. Four main anteroposterior channels converging in the mediorostral pole of the caudate nucleus were distinguished. Seven to eight diagonally oriented channels crossing the previous ones were seen also in the mediolateral axis on the central core of the caudate nucleus. The pattern of organization of the numerous and tortuous striosomal channels was more complicated medially, while the lateral part of the caudate nucleus was represented mainly by the matrix compartment. In addition, a sub-compartmentation of the matrix was demonstrated by retrograde tracing studies made by injecting either horseradish peroxidase-wheat germ agglutinin, [14C]amino acids or a mixture of horseradish peroxidase-wheat germ agglutinin and [14C]amino acids in several areas of the substantia nigra pars reticulata. Labelled patches were seen with both tracers, their topographical localization depended on the nigral injection site but reconstruction analysis indicated that the populations of cells which innervate the substantia nigra pars reticulata originate in the two third lateral parts of the caudate nucleus all along its rostrocaudal extension. Examination of horseradish peroxidase-wheat germ agglutinin labelled cells indicated that not all cells were labelled in patches suggesting a further sub-compartmentation of these patches. Finally, a comparison of the topographical distributions of labelled patches and of striosomes revealed that most patches were located in the extrastriosomal matrix.
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PMID:Three-dimensional organization of the striosomal compartment and patchy distribution of striatonigral projections in the matrix of the cat caudate nucleus. 273 1

A method for determination of picomolar quantities of acetylcholine and choline in solutions and tissue extracts is described. The analytes are injected into a continuous stream of a simple medium flowing through a sequence of enzyme reactors containing acetylcholinesterase, choline oxidase, and peroxidase. Additional reactors with choline oxidase and catalase are used to remove endogenous choline from the tissue extracts in which the content of acetylcholine is to be measured. Reaction products are detected fluorometrically or luminometrically. The limits of sensitivity are about 10 pmol/sample with luminometric and 0.2 pmol/sample with fluorometric detection.
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PMID:Determination of acetylcholine and choline by flow-injection with immobilized enzymes and fluorometric or luminometric detection. 274 18

The electromotor system of the electric eel, Electrophorus electricus, was studied by injection of horseradish peroxidase as a retrograde tracer. The electromotor neurons, which innervate the electrocytes, comprise a midline nucleus, largely dorsal to the spinal canal. Spinal motoneurons lie ventrolaterally. The electromotor and skeletal motor neuron populations correspond to the acetylcholinesterase-negative and -positive cells previously described. The medullary relay neurons were labeled following HRP injection into the spinal cord at a level where electromotor neurons occurred, but not after injection into the cord in the abdominal region rostral to these cells. Other medullary neurons, presumably bulbospinal motor fibers, were labeled after both levels of spinal cord injection. The results suggest that these axosomatic synapses, which are electrically transmitting but morphologically mixed, take up retrograde tracers in a manner similar to chemical synapses and that tracer uptake is at least largely at terminal regions.
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PMID:The electromotor system of the electric eel investigated with horseradish peroxidase as a retrograde tracer. 274 17

A sensitive fluorogenic assay for acetylcholine is described. The assay is based upon the reactions: (1) hydrolysis of acetylcholine to choline and acetate, catalyzed by acetylcholinesterase. (2) Oxidation of choline to betaine and hydrogen peroxide by choline oxidase. (3) Oxidation of p-hydroxyphenylacetic acid by hydrogen peroxide to a fluorescent product, catalyzed by peroxidase. With a sensitivity comparable to chemiluminescence procedures, the assay should find application to those situations requiring the persistence of a fluorescence signal or the necessity of assaying small volumes.
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PMID:A fluorometric assay for acetylcholine with picomole sensitivity. 276 Dec 99

Quail leg buds were grafted in place of chick leg buds or chick wing buds and vice versa at stages 18 to 21 after colonization by muscle precursor cells had been completed. Motor endplate pattern in the plantaris muscle of the grafts was analyzed before hatching by means of esterase and acetylcholinesterase staining techniques. Muscle fibre types were made visual using the myosin ATPase reaction. Investigations are based on the species-specific endplate pattern of the plantaris muscle: multiply innervated fibres in the chick and focally innervated fibres in the quail. Muscle pieces isolated from the adjacent medial gastrocnemius muscle of the grafted legs were histologically examined to judge their species-specific composition. Horseradish peroxidase was injected into the plantaris muscles of both the grafted and the opposite leg as well as in the plantaris muscle of normal quail embryos, in order to be sure that the plantaris muscle of the grafts is innervated by appropriate motoneurons. This procedural design offers for the first time a possibility to test experimentally the influences of motoneurons on endplate pattern formation under conditions corresponding to those in normal ontogenesis. It is shown that such appropriate motoneurons of one species which project to the plantaris muscle of the other species dictate the endplate pattern. When the plantaris muscle is innervated by inappropriate motoneurons, the endplate pattern inherent in the muscle primordium itself becomes realized. A sequence of hierarchically acting factors is proposed to bring different results in line. According to this, the neuronally set programme has priority compared with that set in the muscle. This is true for the normal development and might generate the high neuro-muscular specificity. If under experimental conditions the neuronal programme and the peripheral programme differ, the axons and muscle fibres selectively interact with respect to their inherent characteristics and the muscle-specific programme becomes expressed. If there is a lack of a certain axon type, muscle fibres might become innervated by non-corresponding motoneurons which alter the muscle fibre type.
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PMID:A hierarchy of determining factors controls motoneuron innervation. Experimental studies on the development of the plantaris muscle (PL) in avian chimeras. 280 82


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