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)

We have succeeded in the isolation, culture and morphological characterization of Rana ridibunda stomach enteric plexuses. We have furthermore obtained intra and extracellular bioelectric recordings from the explants in culture. The culture medium used (Eagle MEM), the collagenase digestion and the general culture conditions followed are similar to those applied to mammal enteric plexus explant cultures. The most striking difference is that the solutions were diluted to 70% in order to maintain the osmolar conditions required by the amphibian cells. Acetylcholinesterase, osmium tetroxide-zinc iodide- and para-formaldehyde-induced fluorescence methods reveal similar morphological images from the perivascular fibre plexuses. The different cell types observed by phase contrast light microscopy from the myenteric explants in culture have been identified by comparison with those revealed by the acetylcholinesterase method. The prevailing neurons show piramidal somas; other neurons are bipolar with oval somas and a third type shows oval somas tightly aligned, following sinusoidal courses. The intra and extracellular bioelectric recordings from the explants in culture show that the culture conditions we have applied preserve the electrophysiological properties of the neuronal membranes. These preliminary recordings will allow us to undertake the synaptic characterization of the gastrointestinal neurotransmitters in frogs.
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PMID:Frog stomach enteric plexuses in culture: isolation, morphological characterization and bioelectrical recordings. 213 57

Biochemical measurement of acetylcholinesterase (AChE) activity on sonicates of samples of rat cortex, striatum and cerebellum which had been treated with either 4% formaldehyde (HCHO) or 4% HCHO/0.5% glutaraldehyde suggest that fixation of tissue causes a rather large loss (50-80%) in AChE activity which may vary considerably from region to region of brain. Attempts to protect the activity by treatment with diisopropyl fluorophosphate (DFP) before fixation and reactivation after fixation with pyridine-2-aldoxime methiodide (PAM) were unsuccessful. The results suggest care must be exercised in attempting to use AChE histochemistry on fixed tissue for quantitative measurements.
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PMID:Effect of fixatives on rat brain acetylcholinesterase activity. 275 81

Pulmonary neuroendocrine (NE) cells, dispersed throughout the airway mucosa as single cells and as innervated clusters (neuroepithelial bodies), were isolated from rabbit fetal lung and studied in short-term culture. The effects of culture media and nerve growth factor (NGF) on in vitro maintenance, differentation, and cell kinetics of isolated NE cells were examined. For demonstration of NE cells in intact lung, during cell separation and after culture, immunostaining for serotonin, formaldehyde-induced fluorescence method, histochemical reaction for acetylcholinesterase, and electron microscopy were used. The isolation procedure consisted of mechanical and enzymatic dissociation of lung tissue followed by separation of isolated cells on a discontinuous gradient of Percoll, resulting in 5- to 10-fold enrichment in NE cells. Cell fractions enriched in NE cells were cultured up to 7 days either in supplemented alpha-minimal essential medium with fetal bovine serum or in defined, hormone-supplemented, serum-free medium. NGF (2.5 S 5 to 50 ng/ml) was added to both serum-supplemented and serum-free media; cultures without NGF served as control. The number of serotonin-immunoreactive NE cells maintained in serum-supplemented medium (0.5% fetal bovine serum) increased significantly (p less than 0.05) on days 4 and 7 compared with cultures grown in serum-free medium. NE cells maintained in serum-supplemented medium incorporated [3H]thymidine and their labeling index was significantly increased (p less than 0.01) on day 7, whereas few or no NE cells were labeled in cultures grown in serum-free medium. NGF had no effect on the maintenance or kinetics of NE cells. Cultured NE cells formed elongated (unipolar or bipolar) neurite-like cytoplasmic processes with a button-like ending, regardless of the presence of NGF. Amine accumulated in perinuclear cytoplasm and in button-like endings. Staining for acetylcholinesterase (strongly positive in intact neuroepithelial bodies) was not detectable after separation into single cells, culture, or exposure to NGF. This study demonstrates that NE cells can be isolated from rabbit fetal lung and maintained in short-term culture. Low concentrations of fetal bovine serum enhanced the in vitro maintenance of NE cells, whereas NGF had no such effect. A feeder layer may be also important, since NE cells were closely associated with lung epithelial or fibroblast-like cells. The formation of neurite-like processes appears to be an expression of paracrine/paraneuron-type cell differentiation not mediated by NGF.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:In vitro characteristics of pulmonary neuroendocrine cells isolated from rabbit fetal lung. I. Effects of culture media and nerve growth factor. 286 71

The topographical, ultrastructural, and histochemical features of 23 human vagal paraganglia were analyzed. Nineteen of the 23 paraganglia were found in previously unreported sites; 18 of the 19 were in the cervical part of the nerve, between the carotid bifurcation and the superior thoraco-cervical inlet, and one paraganglion was located in the retrothyroidal part of the left inferior laryngeal nerve. The results of ultrastructural studies (2 cases), the histochemical and formaldehyde-induced-fluorescence studies (3 cases), and specific acetylcholinesterase activity (one case) demonstrate that these structures fulfill many of the modern criteria for paraganglionic tissue. In addition to paraganglia, single, isolated neurons or true micro-ganglia were always found along the trunk and branches of the vagus nerve when multiple sections were examined.
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PMID:Intra and juxtavagal paraganglia: a topographical, histochemical, and ultrastructural study in the human. 318 69

The present study was undertaken to investigate the structural changes in both cholinesterase (ChE)-positive nerve fibers and adrenergic nerves with formaldehyde-induced fluorescence in pregnant and postpartum uteri of both the albino rat and guinea pig. Particular attention was directed to the relationship between these changes and the local factors associated with the growing fetus. ChE reaction was absent in the control and pregnant uterus of the guinea pig. In the albino rat, there were signs of degeneration in pregnancy. These were evidenced by vacuolation of large nerve trunks and the presence of focal segments with very faint reaction along the course of the nerve bundles. Myometrial segments from fetus-containing horns showed some fragmented nerve fibers, but at the same time some other normal ones. Most of the fine nerve bundles gave a weak reaction. Three weeks after delivery, multiple ChE fibers were found in the uterus of the albino rat. The normal appearance was, however, not regained and some nerve fibers were still fragmented. Noradrenergic (NA) nerve fibers were disintegrated and markedly reduced in number in the myometrium of the pregnant uterus of both the guinea pig and albino rat, particularly in the uterine horns that were distended by fetuses. The number of NA fibers was not significantly reduced in the tubal ends of the albino rat uterus. Three weeks after delivery, normal NA fibers were seen in the myometrium of both the albino rat and guinea pig uterus. Nerves with reduced fluorescence reaction were observed less frequently.
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PMID:Changes in cholinergic and noradrenergic nerves in the pregnant and postpartum uterus of the albino rat and guinea pig. 319 14

Nerve fibers supplying the Duvernoy's gland, a venom-secreting oral gland, of the Japanese colubrid snake, Rhabdophis tigrinus, were examined by formaldehyde-induced fluorescence (FIF) and acetylcholinesterase (AChE) histochemistry, immunohistochemistry, and electron microscopy. The innervation by the FIF fibers was rather meager and was restricted to the area around the arteries localized in the interlobular connective tissue. The AChE-reactive fibers, in contrast, were abundantly supplied all over the gland, especially to the lobule consisting of secretory units. Peptide histidine isoleucine (PHI)(1-15)-like immunoreactive fibers were also detected in the gland and proved identical to the AChE-reactive fibers. The reactivities for both AChE and PHI (1-15) were particularly prominent around the blood capillaries distributed in the lobules. Under the electron microscope, nerve fibers were frequently seen to terminate near capillaries subjacent to the secretory unit. Those nerve terminals containing small clear vesicles and dense core granules were devoid of Schwann cell coverage on the side facing the blood capillary. These features suggest that the nerve terminals may possibly release at least a portion of their secretory contents into the blood as neurohormones.
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PMID:Histochemical, immunohistochemical, and ultrastructural characteristics of nerves in the Duvernoy's gland of the Japanese colubrid snake, Rhabdophis tigrinus. 322 1

Purified human erythrocyte acetylcholinesterase was labeled by reductive radiomethylation with saturating amounts of [14C]formaldehyde and sodium cyanoborohydride. Acid hydrolysis and automated amino acid analysis permitted both identification of radiomethylated components by their coelution with radiomethylated standards and quantitation of these components. The methylated N-terminal amino acids glutamate and arginine were observed at levels of 0.66 and 0.34 residues, respectively, per 70-kilodalton subunit, and lysine residues were methylated on their epsilon-amino groups to a level of 7.40 residues per subunit [Haas, R., & Rosenberry, T.L. (1985) Anal. Biochem. 148, 154-162]. In addition, each subunit contained 1.35 residues of methylated ethanolamine and 0.98 residue of methylated glucosamine. Papain digestion cleaved the intact enzyme into two fragments, an enzymatically active hydrophilic fragment and a small hydrophobic fragment that represented the membrane-binding domain. The radiomethylated amino acids were quantitatively retained in the hydrophilic fragment, while the methylated ethanolamine and glucosamine were confined exclusively to the hydrophobic domain fragment. This fragment included the C-terminal dipeptide of the subunit. Peptide sequencing by manual Edman methods was combined with radiomethylation to demonstrate the sequence His-Gly-ethanolamine-Z for the hydrophobic domain fragment. The ethanolamine residue in this sequence is in amide linkage to the C-terminal Gly and is clearly distinct from the ethanolamine residues in Z which are susceptible to radiomethylation in the intact enzyme. Since Z also includes glucosamine and 2 mol of fatty acids [Roberts, W.L. & Rosenberry, T.L. (1985) Biochem. Biophys. Res. Commun. 133, 621-627], we conclude that the membrane-binding domain of human erythrocyte acetylcholinesterase is a covalently linked glycolipid at the C-termini of the subunits.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Identification of amine components in a glycolipid membrane-binding domain at the C-terminus of human erythrocyte acetylcholinesterase. 352 71

In the female rat the pelvic ganglia are situated bilaterally on the surfaces of the rectum and the vagina at the level of the vaginal fornices. They are broom-, club- or long S-shaped, measuring 4-7 mm (long diameter) by 2-4 mm (short diameter) by 1-2 mm (thickness). The ganglion cells are mainly multipolar, though bipolar or unipolar ones are sometimes observed, and range from about 20 to 50 mu in diameter. Clusters of smaller type cells about 7 to 25 mu in diameter, regarded as chromaffin cells, were found in the ratio of 1 to 50 or 70 ganglion cells, using a silver impregnation method. In the majority of ganglion cells, on the surface of cell bodies and processes upon which numerous cholinergic nerve endings are located, the histochemical reaction for acetylcholinesterase (AChE) was of varied intensity. The so-called small, intensely fluorescent cells (SIF cells) arranged in clusters were observed by the formaldehyde-induced fluorescence method. The "vacuolated nerve cells", which contain 1 to 10 or more vacuoles of up to about 20 mu in diameter, were observed in the ganglion. Ultrastructurally the vacuoles contained various numbers of inclusion bodies of different sizes, shapes and structures. These cells showed a synaptic formation with complex membrane specializations on their surface.
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PMID:[Observations on the morphology of the pelvic ganglion of the female rat]. 372 52

HI 6 has been shown to be efficacious in soman intoxication of laboratory animals by reactivation of acetylcholinesterase. To assess possible risks involved in the administration of HI 6 its degradation products were analyzed at pH 2.0, 4.0, 7.4, and 9.0. At pH 2.0, where HI 6 in aqueous solution has its maximal stability, attack on the aminal-acetal bond of the "ether bridge" predominates, with formation of formaldehyde, isonicotinamide, and pyridine-2-aldoxime. Besides, HI 6 decomposes at the oxime group yielding 2-cyanopyridine. Liberation of hydrocyanic acid at pH 2.0 is below 5%. At pH 7.4, primary attack is on the oxime group, resulting in formation of the corresponding pyridone via an intermediate nitrile. The pyridone has been isolated and identified as 2-pyridinone, 1-[(4-carbamoylpyridinio)methoxy)methyl)formate. This major metabolite deaminates further to the 2-pyridinone, 1-[(4-carboxypyridinio)methoxy)methyl) derivative, which ultimately decomposes into formaldehyde, isonicotinic acid, and 2-pyridone. Hydrolysis of the acid amide group probably also occurs with HI 6 itself. Significant amounts of free hydrocyanic acid were only detected in the presence of an alkali trap; otherwise hydrocyanic acid reacts with formaldehyde to yield hydroxyacetonitrile from which hydrocyanic acid can be liberated again. Up to 0.6 equivalents of hydrocyanic acid were evolved at pH 7.4. After repetitive administration and impaired renal elimination of HI 6, e.g. during renal shock, there might be some risk of cyanide intoxication.
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PMID:Studies on the decomposition of the oxime HI 6 in aqueous solution. 382 94

The autonomic nerve supply of the guinea-pig ovary was investigated by a combination of light- and electron microscopy. At the light-microscopic level, adrenergic fibres were identified due to their formaldehyde-induced fluorescence. In addition, the ovary contained acetylcholinesterase-positive fibres. In all parts of the ovary, the adrenergic fibres were most numerous. At the ultrastructural level it was possible to identify the adrenergic nerve terminals with the aid of the false adrenergic transmitter, 5-hydroxy-dopamine. Thus, large numbers of adrenergic terminals, characterized by their content of 50-60 nm, electron-dense synaptic vesicles, were seen within the interstitial gland, where they formed close contacts with the endocrine cells (membrane-to-membrane distance, 20-100 nm). The follicular theca externa was also richly supplied by adrenergic nerves. At this location, close contacts (50-100 nm) were identified between the nerve terminals and the smooth muscle-like cells. Very few adrenergic nerve fibres were present in the theca interna of follicles or in the corpus luteum. Non-adrenergic nerve terminals, characterized by electron-lucent synaptic vesicles of 50-60 nm diameter, were observed together with the adrenergic fibres. They were always present in much lower numbers than the latter. No "p-type" nerves were identified by electron microscopy.
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PMID:Histochemistry and ultrastructure of adrenergic and acetylcholinesterase-containing nerves supplying follicles and endocrine cells in the guinea-pig ovary. 401 87


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