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)

An original immunoenzymatic screening method, based on the use of antigens labeled with the stable enzyme acetylcholinesterase (AChE, EC 3.1.1.7), is described. The high turnover of this enzyme results in a very sensitive detection of antibodies. In this method, monoclonal antibodies from the supernatants of hybridoma cultures are immobilized on a solid phase coated with anti-mouse immunoglobulins and react simultaneously with the appropriate antigen labeled with biotin molecules. In a second step, biotinylated acetylcholinesterase is in turn associated to the system via avidin interactions and subsequently detected by a colorimetric assay. The method appears more sensitive and easier to use than either the corresponding radioimmunological test using a 125I-iodinated antigen or the same type of enzymatic immunoassay performed with biotinylated horseradish peroxidase instead of biotinylated AChE. The combined use of microtiter plates, solid-phase separation, and colorimetric detection allows a high level of automation of the method which makes it very efficient to process a large number of samples. This technique has been successfully applied to the screening of monoclonal antibodies directed against peripheral proteins of the photosystem 1 (PS1) membrane complex in photosynthesis. A complete set of antibodies recognizing these PS1 components was selected. The same technique was also tested in competition immunoassays and appears to be a very precise and useful tool for quantifying PS1 polypeptides in different biological extracts, including sodium dodecyl sulfate-denatured membranes. This can be of special interest for studying the biogenesis of membrane complexes.
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PMID:Screening of monoclonal antibodies using antigens labeled with acetylcholinesterase: application to the peripheral proteins of photosystem 1. 328 14

The sternomastoid muscle of the rat is divided into a white (dominated by fast-glycolytic twitch fibers) and a red (dominated by fast oxidative-glycolytic twitch fibers, but also containing slow-oxidative twitch fibers) compartment. Previous reports on exclusive location of muscle spindles in the red portion were confirmed. On the basis of anterograde labeling with horseradish peroxidase-wheat germ agglutinine conjugate (WGA-HRP) it was shown in this study that, in addition to muscle spindle compartmentalisation, there was also an exclusive occurrence of tendon organs in the red part of the muscle; moreover, fine afferents (III- and IV-afferents) were mainly distributed to this portion as well. Radioimmunassay studies revealed that this part of the muscle contained twice as much substance P as the white part. It could be shown by acetylcholinesterase (AChE) histochemistry that the myelinated fibers of the white branch to the muscle exclusively displayed high enzyme activity which is characteristic for motor fibers; on the other hand, in the branch to the red portion two classes of AChE-positive fibers were found: a large one with a peak in the alpha-range, and a small one with a peak in the gamma-range. In addition, there was also a group of enzyme-negative (sensory) fibers. These results also indicate the red portion of the sternomastoid muscle to be its "sensory compartment".
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PMID:The distribution of anterogradely labeled I--IV primary afferents in histochemically defined compartments of the rat's sternomastoid muscle. 335 41

We describe an automated kinetic method that uses a single aqueous reagent to measure the in vitro hydrolysis of the muscle relaxant succinylcholine. The substrate succinylcholine is hydrolyzed by plasma cholinesterase (EC 3.1.1.8), and the choline produced is oxidized by choline oxidase (EC 11.3.17) in the presence of peroxidase, 4-aminophenazone and phenol, to yield a chromagen with maximum absorbance at 500 nm. The method is reproducible (CV 1.3%), correlates well with a manual procedure using the same substrate (r = 0.994, y = 0.99x - 0.25), and is linear to 150 U/L. The method is well suited to pre-operative screening and detection of "at-risk" individuals, as illustrated by the family of one patient who had a prolonged succinylcholine apnea.
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PMID:Screening for plasma cholinesterase deficiency: an automated succinylcholine based assay. 339 Sep 4

In order to investigate the nigro-tecto-spinal pathway in the rat, the pattern of termination of nigrotectal fibres and the distribution of tectospinal neurons have been investigated in a light and electron microscopic study of the superior colliculus. In addition, the pattern of termination of nigrotectal fibres was compared to the pattern of acetylcholinesterase staining. The light microscopic studies showed that the nigrotectal fibres, which had been identified by anterograde transport of horseradish peroxidase from the substantia nigra, terminated in a distinctive clustered pattern throughout the rostrocaudal extent of the stratum griseum intermedium, stratum album intermedium and adjacent dorsal portion of the stratum griseum profundum of the ipsilateral superior colliculus. The clusters of nigrotectal terminals formed a series of branching, interconnected longitudinal columns which largely corresponded with the pattern of acetylcholinesterase staining. The tectospinal neurons, which had been identified by retrograde transport of horseradish peroxidase from the spinal cord, had mainly large-sized somata, were stellate in shape with multiple long dendrites, and formed variable-sized clusters of 4-15 neurons within lateral regions of the ventral stratum album intermedium and dorsal stratum griseum profundum. In experiments where both the nigrotectal terminals and the tectospinal neurons were labelled by the transport of horseradish peroxidase, the clusters of tectospinal neurons largely corresponded with the regions of densest nigrotectal fibre termination in the lateral regions of the superior colliculus. In addition, a small contralateral nigrotectal projection was localized in the rostrolateral region of the superior colliculus where the crossed fibres terminated in a clustered pattern in alignment with clusters of tectospinal neurons in this region. Electron microscopic examination of the superior colliculus following ibotenic acid lesions in the substantia nigra and horseradish peroxidase injections in the spinal cord showed multiple degenerating nigrotectal boutons in synaptic contact with the soma and the mainstem and secondary dendrites of labelled tectospinal neurons in the lateral regions of the stratum album intermedium and stratum griseum profundum of the superior colliculus. The majority of the degenerating nigrotectal boutons showed electron-lucent degenerative changes and were in axodendritic contact. All of the identified nigrotectal synapses were of the symmetrical type.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The nigrotectal projection and tectospinal neurons in the rat. A light and electron microscopic study demonstrating a monosynaptic nigral input to identified tectospinal neurons. 339 58

In the hatchetfish, the Mauthner cell (M-cell) is thought to be cholinergic based on electrophysiological studies using cholinergic agents and on the localization of acetylcholinesterase (AChE) and alpha-bungarotoxin to M-cell-giant fiber synapses. Immunocytochemical studies have shown that mammalian and non-mammalian cholinergic neurons stain positive for choline acetyltransferase (ChAT), the enzyme responsible for synthesizing acetylcholine. We processed tissue from the goldfish (Carassius auratus) for the immunohistochemical detection of ChAT using the monoclonal antibody AB8 and the peroxidase-antiperoxidase procedure. ChAT immunoreactivity was found in selected areas of the goldfish brain including the cranial nerve nuclei and the ventral horn motoneurons of the spinal cord. Interestingly, the M-cell soma which stains positive for AChE was ChAT negative. This immunohistochemical evidence does not support cholinergic functioning of the Mauthner cell.
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PMID:Choline acetyltransferase immunohistochemical staining in the goldfish (Carassius auratus) brain: evidence that the Mauthner cell does not contain choline acetyltransferase. 353 Mar 76

Centrifugal projections from the brain to the cochlea have been well described in rodents and cats. In order to gain a better understanding of the general mammalian features of this efferent projection system--the olivocochlear (OC) system--we have begun to extend its description to other mammalian orders, particularly primates. This report describes the origin, cellular morphology, and cholinergic nature of OC neurons in squirrel monkey. Olivocochlear neurons were identified after cochlear injection and subsequent retrograde transport of one of the tracers, horseradish peroxidase, True Blue, or Diamidino Yellow. One series of sections was processed to demonstrate the tracer and an adjacent series was processed to demonstrate acetylcholinesterase (AChE). In some cases, a series of sections was immunohistochemically processed to identify the presence of choline acetyltransferase (CAT), the synthesizing enzyme for acetylcholine. Approximately 1,700-1,800 OC neurons were contained in five distinct regions surrounding the major nuclei of the superior olivary complex (SOC), namely: dorsal to medial superior olive (MSO); between MSO and lateral superior olive (LSO); lateral to LSO; medial to SOC; and in the ventral nucleus of the trapezoid body (VTB). These neurons were larger in the regions dorsal to MSO, lateral to LSO, and within VTB; they tended to be smaller in the regions between MSO and LSO and medial to SOC. Neuronal shapes varied among regions and included oval, elongate, round, and multipolar cells. In further support of their cholinergic nature as implied by AChE reactivity, OC neurons also stained positively for the cholinergic marker, CAT.
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PMID:Olivocochlear neurons in the squirrel monkey brainstem. 354 42

The terminal nerve is composed of a morphologically heterogeneous population of unipolar, bipolar and multipolar neurons located in the nasal and intracranial cavities of vertebrates. The question has arisen as to whether these neurons are neurochemically heterogeneous and therefore possibly functionally different as well. Among the substances localized in the terminal nerve are acetylcholinesterase and luteinizing hormone-releasing hormone-like immunoreactive material. We have developed a double-label procedure, combining immunocytochemistry and enzyme histochemistry to determine whether these two substances are localized within different populations of terminal nerve neurons. Compatibility of the two procedures was accomplished by modifications of the fixative and primary antibody solutions. In the immunocytochemical step, the avidin-biotin-peroxidase complex coupled to a new chromogen, Chromo-red, produced a bright red reaction product in neurons containing luteinizing hormone-releasing hormone-like material. This reaction product was easily differentiated from the black silver-intensified acetylcholinesterase label. In both neonatal and adult preparations, a large population of terminal neurons contained the acetylcholinesterase label only, whereas a smaller population contained both acetylcholinesterase and luteinizing hormone-releasing hormone-like material. The acetylcholinesterase-containing population of neurons was concentrated peripherally and included multipolar neurons. In contrast neurons with the two substances co-localized were unipolar or bipolar and were concentrated centrally. The simultaneous visualization of acetylcholinesterase and luteinizing hormone-releasing hormone-like material in the same tissue section enable the differentiation of two separate neurochemically defined populations of terminal neurons. The distribution of these two neuronal types was the same in neonatal and adult animals. These data provide support for a functional diversity of terminal neurons.
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PMID:Acetylcholinesterase and luteinizing hormone-releasing hormone distinguish separate populations of terminal nerve neurons. 354 Jul 22

The nucleus isthmi of teleost fish, amphibians, reptiles and birds, and its probable homologue, the nucleus parabigeminalis of mammals, share in common certain features such as location in the dorsal tegmentum and reciprocal connectivity with the optic tectum. In gymnotid fish the nucleus isthmi is located dorsolaterally in the brainstem tegmentum, ventral to the torus semicircularis and the lateral mesencephalic reticular area and dorsal to the rostral nucleus praeeminentialis. The nucleus isthmi has an ovoid shape, with a compact cellular part on its dorsal, medial and ventral aspects surrounding a hilar region with a sparse population of larger cells. Following wheat germ agglutinin-conjugated horseradish peroxidase injections into the optic tectum, anterogradely labeled fine terminals were observed leaving the tectobulbar tract and entering the ipsilateral nucleus isthmi via its laterally facing hilar region. Retrogradely labeled cells were present in the nucleus isthmi on both sides, indicating the presence of a bilateral isthmotectal projection similar to that reported in amphibians. The putative isthmal nucleus stains densely for acetylcholinesterase. Based on the similarity of its location, shape, cholinesterase histochemistry and reciprocal connectivity with the optic tectum, we identified this structure as the nucleus isthmi of gymnotids. An interesting observation of this study was that the nucleus isthmi, in addition to receiving fine terminals from the optic tectum, is also the recipient of a sparser population of thicker-caliber afferent fibers which terminate not only in the large-celled hilar region but also within the smaller-celled component of the nucleus; this projection appears to emanate from the torus semicircularis dorsalis.
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PMID:Identification of a nucleus isthmi in the weakly electric fish Apteronotus leptorhynchus (Gymnotiformes). 356 45

We describe a method for measuring plasma cholinesterase (EC 3.1.1.8) and dibucaine and fluoride numbers by using the Cobas-Bio. Benzoyl choline chloride is used as substrate. Reaction conditions are the same as in the corresponding manual method. The reaction is stopped with physostigmine. Choline oxidase (EC 1.1.3.17) is coupled with 4-aminoantipyrene. In the presence of peroxidase (EC 1.11.1.7), the 2-hydroxy-3,5-dichlorobenzenesulfonate indicator reaction gives a red product, measured at 505 nm. The analyzer is used in the "Multi Run" mode, with plasma cholinesterase and dibucaine and fluoride inhibition concurrently measured for eight samples. Coefficients of correlation between the manual and present method for plasma cholinesterase and dibucaine and fluoride numbers in 40 patients of various phenotypes were 0.843, 0.923, and 0.717, respectively. The inter-batch CV for each of the three assays was 2% to 3%.
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PMID:Cholinesterase assay automated in the Cobas-Bio centrifugal analyzer. 360 67

Blastomeres removed from early cleavage stage ascidian embryos and reared to 'maturity' as partial embryos often elaborate tissue-specific features typical of their constituent cell lineages. We used this property to study recent corrections of the ascidian larval muscle lineage and to compare the ways in which different lineages give rise to muscle. Our evaluation of muscle differentiation was based on histochemical localization and quantitative radiometric measurement of a muscle-specific acetylcholinesterase activity, and the development of myofilaments and myofibrils as observed by electron microscopy. Although the posterior-vegetal blastomeres (B4.1 pair) of the 8-cell embryo have long been believed to be the sole precursors of larval muscle, recent studies using horseradish peroxidase to mark cell lineages have shown that small numbers of muscle cells originate from the anterior-vegetal (A4.1) and posterior-animal (b4.2) blastomeres of this stage. Fully differentiated muscle expression in isolated partial embryos of A4.1-derived cells requires an association with cells from other lineages whereas muscle from B4.1 blastomeres develops autonomously. Clear differences also occurred in the time acetylcholinesterase activity was first detected in partial embryos from these two sources. Isolated b4.2 cells failed to show any muscle development even in combination with anterior-animal cells (a4.2) and are presumably even more dependent on normal cell interactions and associations. Others have noted an additional distinction between the different sources of muscle: muscle cells from non-B4.1 lineages occur exclusively in the distal part of the tail, while the B4.1 descendants contribute those cells in the proximal and middle regions. During the course of ascidian larval evolution tail muscle probably had two origins: the primary lineage (B4.1) whose fate was set rigidly at early cleavage stages and secondarily evolved lineages which arose later by recruitment of cells from other tissues resulting in increased tail length. In contrast to the B4.1 lineage, muscle development in the secondary lineages is controlled less rigidly by processes that depend on cell interactions.
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PMID:Determinative properties of muscle lineages in ascidian embryos. 365 70


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