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)

Systemic injection of monoclonal antibodies to neural acetylcholinesterase in adult rats caused a syndrome with permanent, complement-mediated destruction of presynaptic fibers in sympathetic ganglia and adrenal medulla. Ptosis, hypotension, bradycardia, and postural syncope ensued. In sympathetic ganglia, acetylcholinesterase activity disappeared from neuropil but not from nerve cell bodies. Choline acetyltransferase activity and ultrastructurally defined synapses were also lost. Electrical stimulation of presynaptic fibers to the superior cervical ganglion ceased to evoke end-organ responses. On the other hand, direct ganglionic stimulation remained effective, and the postganglionic adrenergic system appeared intact. Motor performance and the choline acetyltransferase content of skeletal muscle were preserved, as was parasympathetic (vagal) function. This model of selective cholinergic autoimmunity represents another tool for autonomic physiology and may be relevant to the pathogenesis of human dysautonomias.
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PMID:Autoimmune preganglionic sympathectomy induced by acetylcholinesterase antibodies. 217 9

We have compared the biochemical expression of cholinergic enzymes with the morphological differentiation of efferent nerve fibers and endings in the cochlea of the postnatally developing mouse. Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) are present in the newborn cochlea at specific activities 63% and 25%, respectively, of their mature levels. The relative increases in ChAT, in AChE, and in its molecular forms over the newborn values start about day 4 and reach maturity by about day 10. The biochemical results correlate well with the massive presence of nerve fibers stained immunocytochemically for ChAT and AChE or enzymatically for AChE in the inner and outer hair cell regions. Ultrastructral studies, however, indicate the presence of only few vesiculated fibers and endings in the inner and outer hair cell regions. The appearance of large, cytologically mature endings occurs only toward the end of the third postnatal week. The discrepancy may be resolved in the electron microscopy using the enzymatic staining for AChE. Labeling is seen on many nonvesiculated fibers and endings in the hair cell regions, suggesting that the majority of the efferent fibers in the perinatal organ may be biochemically differentiated but morphologically immature. The results may imply that the efferents to inner and outer hair cells develop earlier than indicated by previous ultrastructral studies. Moreover, the pattern of development suggests that in the cochlea, as in other tissues, the biochemical differentiation of the efferent innervation may precede the morphological maturation.
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PMID:Biochemical and morphological differentiation of acetylcholinesterase-positive efferent fibers in the mouse cochlea. 219 19

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity, and the affinity and number of muscarinic binding sites (as reflected by specific 3H-quinuclidinyl benzilate binding) were determined in the ciliary muscle of rhesus monkeys ranging in age from 1-34 years. No age dependence was evident for any of these parameters. Within the limits of their specificity and precision, the data indicate that biochemical alterations in ciliary neuromuscular mechanisms do not account for the age-related loss of ciliary muscle configurational responses to topical pilocarpine and electrical stimulation of the Edinger-Westphal nucleus in the rhesus monkey.
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PMID:Ciliary muscle muscarinic binding sites, choline acetyltransferase, and acetylcholinesterase in aging rhesus monkeys. 224 6

The activities of choline acetyltransferase and acetylcholinesterase were assayed in submicrogram samples from layers of pigeon retina. Red and yellow fields were sampled separately to investigate quantitatively the relationship between these enzymes of acetylcholine metabolism and the gradient of inner plexiform layer complexity, increasing from the yellow field to the red. Choline acetyltransferase and acetylcholinesterase activities were concentrated in and near the inner plexiform layer, within which two peaks of activity for each enzyme were obtained. The distributions of enzyme activities indicate that populations of amacrine cells in the pigeon retina are cholinergic. The quantitative similarities between the enzyme activities in red and yellow fields suggest that the cholinergic system may not be specifically involved in the increase in inner plexiform layer complexity across the pigeon retina.
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PMID:Distributions of choline acetyltransferase and acetylcholinesterase activities in the retinal layers of pigeon red and yellow fields. 230 56

The presence of 10(-5) M retinoic acid (RA) in the culture medium of LA-N-1, a catecholaminergic cell line, and LA-N-2, a cholinergic cell line, enhanced their morphological differentiation. Tyrosine hydroxylase (TH) activity of the LA-N-1 cells was increased in the RA-treated cells compared with control cultures at day 4 and remained elevated. Choline acetyltransferase (ChAT) activity in the LA-N-2 cells gradually increased until 8 days in vitro (DIV) both in the untreated control and the RA treated cultures. This activity in control and treated cells decreased gradually to a constant level of activity. The ChAT activity at 8 DIV of RA-treated LA-N-2 cells was increased 2.1-fold (P less than 0.001) as compared to the control cultures. This increase in ChAT activity was accompanied by a 73% decrease of acetylcholinesterase (AChE) activity in LA-N-2 cells by 8 DIV. AChE activity of LA-N-1 cells was unchanged during the time course of the experiment. Phospholipase-A2 (PL-A2) activity in RA-treated LA-N-2 cells was increased at day 4 as compared with the control cultures. There were no differences observed in phospholipase-D (PL-D), choline kinase and GPC-phosphodiesterases activities in RA-treated and -untreated LA-N-1 and LA-N-2 cells.
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PMID:Enzymatic activities during differentiation of the human neuroblastoma cells, LA-N-1 and LA-N-2. 235 89

Choline acetyltransferase, the biosynthetic enzyme for acetylcholine, is thought to be a marker for cholinergic neurons. This report presents an analysis of the pattern of choline acetyltransferase-like immunoreactivity in the superior colliculus of the cat. A dense network of highly varicose immunoreactive fibers pervaded the superficial gray and optical layer. The density of the fiber network in the superficial layers was heterogeneous, forming a mosaic pattern with a period of about 400 microns. The antigen was also located in numerous small perikarya embedded in this network. This neuronal population reached a density of 2,000 cells/mm3 of the superficial gray layer and suggested the presence of a substantial cholinergic system originating in the superior colliculus. A detailed comparison was made between the pattern of choline acetyltransferase-like immunoreactivity and the distribution of acetylcholinesterase activity. By comparisons of adjacent sections, both staining patterns were found to be similar in all collicular layers. In particular, the compartmental distribution of immunoreactivity in the intermediate collicular layers seemed to mimic the pattern of acetylcholinesterase staining. A double-staining technique demonstrated a near-perfect correlation between the two patterns. In conclusion, there was no indication of heightened acetylcholinesterase activity without an associated elevation in choline acetyltransferase-like immunoreactivity throughout the superior colliculus. In this part of the brain, the presence of the putative cholinergic terminals could fully account for the distribution of acetylcholinesterase activity.
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PMID:Choline acetyltransferase-like immunoreactivity in the superior colliculus of the cat and its relation to the pattern of acetylcholinesterase staining. 235 29

Choline acetyltransferase (ChAT; EC 2.3.1.6) and acetylcholinesterase (AChE; EC 3.1.1.7) activities were measured in cynomolgus monkey ciliary muscle 1 month and 6 or more months after ciliary ganglionectomy (CG) or post-ganglionic ciliary neurectomy (PCN). ChAT activity was undetectable and AChE activity was elevated 1 month after CG or PCN, while both averaged about 30% of normal levels 6 or more months after denervation. Four out of six eyes reinnervated by functional criteria 6-12 months after CG or PCN. In one of the two remaining eyes permanently denervated, ChAT was absent from the ciliary muscle. In the other, ChAT activity was about 50% of normal, similar to the reinnervated eyes, but the regenerated cholinergic nerves were not approximated to the ciliary muscle fibers.
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PMID:Ciliary muscle choline acetyltransferase and acetylcholinesterase after ciliary ganglionectomy. 240 48

Degeneration of cholinergic neurons from the basal forebrain nuclei is suspected to be the cause of Alzheimer disease. We have developed dissociated cultures of cholinergic neurons from these nuclei (the nucleus basalis of Meynert, the medial septal nucleus, and the diagonal band nuclei). Brain slices of the forebrains were made by a vibratome, and the basal forebrain nuclei were dissected out, dissociated, and cultured. Choline acetyltransferase immunocytochemistry and acetylcholinesterase cytochemistry revealed large cholinergic cells (average diameter, 20-25 micron) in these cultures. About 75% of large neurons (20 micron or larger in diameter) were cholinergic. Electrophysiological experiments were performed on these large neurons. The neurons usually did not show spontaneous firing, but steady depolarizations produced trains of action potentials, which adapted quickly. The neurons responded with depolarization to the application of L-glutamic acid. Substance P produced depolarization (sometimes hyperpolarization), and during the depolarization membrane resistance was increased.
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PMID:Dissociated cell culture of cholinergic neurons from nucleus basalis of Meynert and other basal forebrain nuclei. 241 32

Light and electron microscopic peroxidase-antiperoxidase immunocytochemistry has been used to localize choline acetyltransferase, substance P and enkephalin in the hypoglossal nucleus of the rat. Choline acetyltransferase immunoreactivity was observed in motoneurone cell bodies and proximal dendrites, in large varicosities in the surrounding neuropil and in nerve terminals in synaptic contact with immunostained motoneurones. Most choline acetyltransferase immunostained terminals which made synaptic contact with motoneurone cell bodies and proximal dendrites possessed prominent subsynaptic cisterns and belong to the terminal type referred to in the literature as C or L. Substance P and enkephalin immunoreactivity did not occur in motoneurones but was seen in fibres and synaptic terminals. Substance P immunoreactive fibres made multiple axosomatic contacts while enkephalin immunoreactive terminals made synaptic contact mainly with large and small dendrites. C terminals were not stained for either substance P or enkephalin. This study provides immunocytochemical support for the classic identification of hypoglossal motoneurones as cholinergic and in addition shows that these neurones are innervated by a number of morphologically and chemically distinct terminal types. C terminals have previously been shown to contain cholinesterase and our demonstration that these terminals contain choline acetyltransferase thus provides additional evidence for their cholinergic nature and for a cholinergic innervation of hypoglossal motoneurones. The origin of the immunoreactive terminals was not identified in this study but possible candidates include the raphe nuclei for substance P. and propriobulbar interneurones for choline acetyltransferase.
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PMID:Inputs to motoneurones in the hypoglossal nucleus of the rat: light and electron microscopic immunocytochemistry for choline acetyltransferase, substance P and enkephalins using monoclonal antibodies. 242 Nov 99

The influence of dexamethasone on the development of neurons and oligodendrocytes was studied in serum-free, aggregating rat brain cell cultures. Synaptogenesis and myelination occur in this culture system. The concentration of myelin basic protein and the activity of 2',3'-cyclic nucleotide 3'-phosphodiesterase were used as oligodendroglia and myelin markers. Choline acetyltransferase and acetylcholinesterase served as neuronal markers, glutamine synthetase reflected astrocyte differentiation, while ornithine decarboxylase served as a general marker for cell growth and maturation. This study showed that dexamethasone stimulated the differentiation of cholinergic neurons and astrocytes. The effect of dexamethasone on oligodendroglial differentiation and myelination depended on the stage of development: during the early phase of myelination dexamethasone had a stimulatory effect, whereas at a later stage it showed a significant inhibition.
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PMID:Dexamethasone stimulates the biochemical differentiation of fetal forebrain cells in reaggregating cultures. 242 5


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