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 putative neurotoxicity of the organophosphorus compound triphenyl phosphite (TPP) was examined in Long Evans, adult male rats. Animals were exposed to two 1.0 ml/kg (1184 mg/kg) injections (sc) of TPP spaced 1 week apart and sampled for biochemical and neuropathological examination. At the time of sampling, rats displayed dysfunctional changes including tail rigidity, circling, and hindlimb paralysis. Neuropathic damage was confined to the lateral and ventral columns of all spinal levels and consisted of myelin ellipsoids and giant axonal swellings filled with smooth endoplasmic reticulum. Wallerian-like degeneration was observed in the spinal roots, the sciatic nerve, and tibial branches. Biochemical assessment of brain acetylcholinesterase (AChE) and neurotoxic esterase (NTE) activity was determined 1, 4, 24, 48, and 72 hr after the second TPP treatment. Both enzyme activity concentrations were depressed maximally at 48 hr postexposure by 30 and 39%, respectively. Serum cholinesterase, sampled 48 hr after the second TPP exposure was depressed by 33%. Data from this study indicate that subchronic exposure to the organophosphite TPP results in severe neurotoxic consequences which differ from those previously described in rats with organophosphorus-induced delayed neuropathy.
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PMID:Biochemical and neuropathological assessment of triphenyl phosphite in rats. 396 10

In chromaffin cells of the adrenal medulla, catecholamines are stored in secretory granules. Different methods have been described to purify chromaffin granules. In the present study, storage granules were prepared using isoosmotic self-generating Percoll gradients or hyperosmotic sucrose gradients, and a comparison of their physical properties in response to osmotic changes was made. Catecholamines, dopamine beta-hydroxylase activity and protein were detected both in the external medium and in the granule fraction according to the medium osmolality. Suspension turbidity was used as a measure of organelle integrity. Acetylcholinesterase activity was found to be associated with both isoosmotically and hyperosomotically prepared granules. The total acetylcholinesterase activity was determined after adding Triton X-100 to the assay medium. When adrenal medullary tissue was homogenized in buffers containing echothiopate, an inhibitor of acetylcholinesterase, only 15-20% of enzyme activity was inhibited, excluding the possibility that main granule acetylcholinesterase could be due to contamination by plasma membrane fragments, endoplasmic reticulum and Golgi membranes. When granules were suspended in hypoosmotic buffers, a soluble acetylcholinesterase form was released into the external medium, while an insoluble acetylcholinesterase form was still found associated with the membrane fraction. Soluble acetylcholinesterase was found to be released differently than soluble dopamine beta-hydroxylase, indicating that acetylcholinesterase may be associated with a more osmotically resistant granule population.
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PMID:Osmotic fragility of chromaffin granules prepared under isoosmotic or hyperosmotic conditions and localization of acetylcholinesterase. 398 18

Using the indirect thiocholine method, the ultrastructural localization of acetylcholinesterase (AChE) activity in the normal rat submandibular gland was studied. Cytochemical demonstration of AChE is based on coupling the hydrolysis of acetylthiocholine iodide to the precipitation of heavy metal salts. AChE-associated reaction product was selectively revealed in the perinuclear space and in the endoplasmic reticulum of the intercalated duct cells, in some cells of granular convoluted tubules, and in the striated duct epithelium, as well as in the myoepithelial cells. Although AChE activity generally occurred inside the cells, electron-dense precipitates were shown in intercellular space and in the stroma of the gland. Fine localization of AChE activity was also found in nerve bundles, predominantly between axons and between axons and Schwann cell. Our observations indicate that AChE is synthesized in the epithelium of the ducts and in the myoepithelial cells of the salivary gland. It is not known yet whether this enzyme is released from the intracytoplasmic membrane system into the extracellular space and then transported to the regions of the gland innervation. Conceivably AChE synthesized in the submandibular gland cells could also be considered an inhibitory modulator of the regulatory functions of biologically active polypeptides.
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PMID:Fine structural localization of acetylcholinesterase activity in rat submandibular gland. 398 73

The transport of norepinephrine and two key enzymes involved in its synthesis, tyrosine hydroxylase (EC 1.14.3a) and dopamine beta-hydroxylase (EC 1.14.2.1), has been studied in relation to other axonal constituents in ligated chicken sciatic nerves. Norepinephrine, tyrosine hydroxylase, and dopamine beta-hydroxylase activity all increased proximal to the constriction over a 20-hr period. The rate of transport of norepinephrine, tyrosine hydroxylase, and dopamine beta-hydroxylase were calculated as 2.6, 1.9, and 3.4 mm/hr, respectively. The only enzyme marker to show a similar rate of accumulation was acetylcholinesterase (EC 3.1.1.7), a putative marker for endoplasmic reticulum. The rapid axoplasmic transport of tyrosine hydroxylase from the cell bodies to the terminals of sympathetic neurons may be adequate to account for the elevated amounts of this enzyme in chronically active axon terminals, without the necessity to invoke peripheral axonal synthesis of the enzyme to explain such elevated amounts.
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PMID:Rapid axoplasmic transport of tyrosine hydroxylase in relation to other cytoplasmic constituents. 411 72

Acetylcholinesterase (AChE) activity has been studied in the myoblast of skeletal muscle of the 9-13 day fetal rabbit. Cytochemical activity is present in the nuclear envelope and the endoplasmic reticulum, including its derivatives the subsurface reticulum and the sarcoplasmic reticulum. End product is also found in the Golgi complex of the more differentiated myoblasts. The formation of reticulum-bound acetylcholinesterase in the myoblast appears to be independent of nerve-muscle contact, since the enzyme is present before the outgrowth of the spinal nerve. The nerve lacks cytochemical end product until the myoblast is well differentiated. Possible mechanisms of spontaneous muscle contraction have been discussed. A second type of myotomal cell, which exhibits a poorly localized end product of AChE activity, has been described. The ready solubility of the enzyme or diffusibility of its end product suggests that the enzyme may be a lyoesterase. This cell may be the precursor of the morphologically undifferentiated cell which is closely apposed to the myotubes in later stages of skeletal muscle development. Biochemical studies show a significant increase in AChE activity in the dermomyotome by day 12, when many of the myoblasts are well differentiated and the second type of myotomal cell is prominent. Cytochemical studies have indicated that many of the cells in the sample lack reaction product of enzymic activity, whereas others are very active. Biochemical values, therefore, reflect the amount of enzyme in the dermomyotome as a whole, but give little information on the enzymic content of individual cells.
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PMID:The appearance of acetylcholinesterase in the myotome of the embryonic rabbit. An electron microscope cytochemical and biochemical study. 425 59

In the nine day old embryo, acetylcholinesterase (AChE) is found in the reticulum, i.e. the nuclear envelope, endoplasmic reticulum, and Golgi complex, of a few cells in the neural crest. When the neurite first enters the neural tube, reticulum-bound enzyme is present also in the varicosity of the growth cone of the bipolar neuroblast. At later stages, AChE in the neuroblast has a dual distribution; in addition to the reticulum, activity also appears at the axolemmal surface. The axolemmal activity is found initially on the distal portions of axons in the posterior fasciculus and then progressively appears along the nerve roots in a distal to proximal direction. Very little reticulum-bound enzyme is present within the axon proper. After the 13th day the levels of AChE activity in the posterior fasciculus greatly exceed those in the dorsal root or in the ganglion. Enzymatic activity in the dorsal root equals or exceeds that in the posterior fasciculus by day 16, and both areas are considerably more active than the ganglion.
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PMID:The appearance of acetylcholinesterase in the dorsal root neuroblast of the rabbit embryo. A study by electron microscope cytochemistry and microgasometric analysis with the magnetic diver. 545 12

Examination of the secretory profile and subcellular localization of some of the multiple export products of the adrenal medullary chromaffin cells indicates that several compartments (chromaffin vesicle, lysosomes, endoplasmic reticulum) are coupled to specific receptors and to cell depolarization through Ca2+-dependent mechanism(s). The activation of the release process results in the concerted cosecretion of endogenous catecholamines, newly incorporated catecholamines, adenine nucleotides, chromogranins, dopamine beta-hydroxylase (EC 1.14.17.1), enkephalins and related opioid peptides, stored ascorbate and newly incorporated ascorbate, lysosomal hydrolases, and soluble acetylcholinesterase. This complex organization for the coexistence of these multiple putative messengers and their cosecretion may be relevant to other endocrine cells and neurons where coexistence of transmitters has been found. This coexistence in multiple secretory compartments may provide the subcellular basis for independent regulation of the synthesis, packaging, and secretion of individual transmitters within the multiplicity of putative messengers secreted by a particular endocrine cell or nerve terminal.
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PMID:Biochemical and functional evidence for the cosecretion of multiple messengers from single and multiple compartments. 613 25

Prostaglandins E1 and E2 are specifically bound by particulate fractions from bovine adrenal medulla. The subcellular localization of these binding sites has been investigated by comparing their distribution in subcellular fractions obtained by differential and gradient centrifugation to those of marker enzymes for various organelles. Prostaglandin E2 binding sites were purified about 16-fold with respect to the homogenate in a fraction which was highly enriched in plasma membranes on the basis of the activities of the marker enzymes acetylcholinesterase and calcium-dependent ATPase, which were both purified by about 12-fold in this fraction. The plasma membrane fraction contained relatively low activities of marker enzymes for mitochondria (monoamine oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), Golgi (galactosyl transferase) and chromaffin granule membranes (dopamine beta-hydroxylase). The only other fractions enriched in prostaglandin E2 binding sites were those for the endoplasmic reticulum and the Golgi, in which the binding sites were purified about 4-fold and 7-fold, respectively. This is probably due mainly to contamination with plasma membranes, since calcium-dependent ATPase and acetylcholinesterase were each purified to a similar extent in these two fractions. These data suggest that the high-affinity prostaglandin E2 binding sites of the adrenal medulla are localized primarily on the plasma membranes of the medullary cells.
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PMID:Subcellular localization of prostaglandin E2 binding sites in bovine adrenal medulla. 614 8

Reversal of direction (turnaround) of axonal transport of particle-specific enzyme activities was studied at a ligature placed on rat sciatic nerve. In the principal experiment, the ligature remained on the nerve in vivo several hours, allowing enzyme activities (acetylcholinesterase, acid phosphatase, and monoamine oxidase) to accumulate immediately proximal to the tie. The nerve was then tied a second time, proximal to the first tie, and incubated in vitro for several more hours. Accumulation of enzyme activities just distal to the second tie was measured. This second accumulation, of activities traveling in the retrograde direction, was shown to be the result of turnaround in several ways. (1) The increase in activity distal to the second tie was equal to the decrease in activity proximal to the first. (2) The increase in enzyme activities distal to the second tie was greatly reduced when the accumulation proximal to the first tie was trapped by placing a third tie between the first and second ties. (3) It was shown that the activity that accumulated distal to the second tie could not have been in retrograde motion at the time of the first tie. (4) Accumulation distal to the second tie was not a function of the length of nerve segment included between the two ties. In contrast to the consistent occurrence of turnaround of orthograde flow, turnaround of retrograde flow could not be demonstrated. Turnaround transport was blocked by incubation in the cold and in the presence of NaCN or vinblastine. The turnaround process operated on all three enzymes studied, suggesting that it operates on lysosomes and mitochondria, as well as on the endoplasmic reticulum-like material bearing acetylcholinesterase. Evidence for the participation of the transport process in the renewal of AChE in the distal portions of the axon was obtained in experiments using diisopropylphosphorofluoridate and cycloheximide.
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PMID:Turnaround of axoplasmic transport of selected particle-specific enzymes at an injury in control and diisopropylphosphorofluoridate-treated rats. 616 Dec 27

Ciliary ganglia (CG) of cats were stained for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) by the bis-(thioacetoxy) aurate (I), or Au(TA)2, method for examination by electron microscopy. Acetylcholinesterase was localized along the axolemmas of the preganglionic fibers and their terminals and on the plasmalemmas of the perikarya and dendrites of the ganglion cells, as in the cat superior cervical ganglion (SCG). In contrast to the SCG, AChE was also found in significant amounts in the rough endoplasmic reticulum of the CG cells and dendrites, and in varying but high concentrations in channels of extracellular space in the complex capsular region surrounding the perikarya and dendrites. Butyrylcholinesterase was confined chiefly to the dendritic and perikaryonal plasma membranes of the ganglion cells, as in the SCG. Lysosomes and mitochondria were stained chiefly for non-cholinesterase enzymes, as indicated by the physostigmine-treated controls. The significance of these distributions is discussed.
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PMID:Electron microscope localization of acetylcholinesterase and butyrylcholinesterase in the ciliary ganglion of the cat. 620 47


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