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 cercariae of Eurytrema pancreaticum (Janson, 1889) possess four types of gland cells - proper cystogenic, penetration, ventral and dorsal gland cells. The secretion of ventral and dorsal gland cells is released into the tegument. The proper cystogenic gland cells are the largest and their contents serve for the formation of the cyst wall of metacercariae in the second intermediate host. The secretion of proper cystogenic gland cells contains besides neutral mucosubstances also acid mucosubstances with both carboxyl- and sulphogroups digestible with beta-glucuronidase. The secretion of penetration gland cells contains neutral mucosubstances and proteins with tyrosine, tryptophan and SS groups. The ventral gland cells contain mostly acid mucosubstances with sulphogroups, which are digested with beta-glucuronidase, and proteins with tyrosine, tryptophan and SH groups. The rudimentary dorsal gland cells contain a small amount of acid mucosubstances. The whole tegument of cercariae and the two main collecting canals of the excretory system exhibit a high alkaline phosphatase activity. The nerve ring and the main nerve truncs contain proteins with SH groups and hydrophilic lipids and exhibit a cholinesterase activity. The suckers contain a larger amount of glycogen.
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PMID:Histochemistry of gland cells of Eurytrema pancreaticum cercariae. 16 44

After a single injection of calcitonin (20 M.R.C. units/kg body wt.) marked decreases in both Ca2+ and free tryptophan in plasma were observed, during the initial period of the treatment (up to 1 h). However, 5-hydrotryptamine contents of the whole brain and the cerebral acetylcholinesterase activity were greatly enhanced. The cerebellar acetylcholinesterase activity was not influenced by calcitonin.
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PMID:Calcitonin-mediated changes in plasma tryptophan and brain 5-hydroxytryptamine and acetylcholinesterase activity in rats. 63 54

Light and electron microscopic histochemical reactions were studied in the cells of pars intermedia of the rat. The possible correlations between enzymatic reactions and endocrine functions of these cells were discussed. By combined formaldehyde and chloral vapour treatment the cells of the pars intermedia exhibited a strong yellow fluorescence suggesting the presence of a peptide or peptides with NH2-terminal tryptophan. Masked metachromasia after acid hydrolysis was probably due to these peptides. Only a weak or no alpha-glycerophosphate dehydrogenase and nonspecific esterase activity was observed in the cells of pars intermedia compared to the cells of pars distalis suggesting low production rate of hormone synthesis. Specific and non-specific cholinesterases were demonstrated light and electron microscopically constantly in the cells bordering the lobules. These cells probably represent a certain type of glial cells. In the other cells the enzymatic activities varied markedly in intensity and distribution showing different ultrastructural localizations. Thus cholinesterase activities in the cells of pars intermedia reflect possibly different functional stages of the cells in their hormone production, storage and secretion processes.
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PMID:Observations on the functional cytochemistry of pars intermedia of the rat hypophysis. 124 48

Picolinic acid, a pyridine monocarboxylic acid derived from tryptophan metabolism by the kynurenine pathway, was shown to block cortical cholinergic neurotoxicity induced by quinolinic acid (QUIN), a pyridine dicarboxylic acid yielded by the same pathway. This study examined the specificity of the anti-toxic effect of picolinic acid by comparing its effect with several structurally related mono- and dicarboxylic acids, and by evaluating its potential to influence cholinergic neurotoxicity produced by kainic, ibotenic and quisqualic acid. Picolinic acid or related agents were injected alone or in combination with a fixed dose of QUIN into the right nucleus basalis magnocellularis (nbM) of rats anesthetized with halothane. Cholinergic neurotoxicity was assessed 7 days post injection by measuring choline acetyltransferase (ChAT) activity in the frontoparietal cortex on the injected and uninjected side. In picolinate experiments, the staining of nbM neurons by acetylcholinesterase (AChE) histochemistry was also examined. Focal injections of QUIN depleted cortical ChAT activity and staining of AChE in the nbM. Co-injection of picolinic acid with QUIN attenuated the decline in these two cholinergic neuron markers. Isonicotinate (4-pyridine monocarboxylate), but not nicotinate (3-pyridine monocarboxylate), significantly attenuated QUIN's effect on cortical ChAT activity. Among several dicarboxylic acids examined, only dipicolinate (2,6-pyridine dicarboxylate) showed activity. It produced a modest QUIN-like effect, but in co-injection experiments it attenuated the QUIN-induced decrease in cortical ChAT. When co-injected into the nbM with a neurotoxic dose of kainic, ibotenic or quisqualic acid which produced a neurotoxic response comparable to that of QUIN, picolinic acid attenuated kainic acid-induced neurotoxicity, but not ibotenate or quisqualate neurotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Action of picolinic acid and structurally related pyridine carboxylic acids on quinolinic acid-induced cortical cholinergic damage. 149 49

The distribution of amino acids between plasma, liver and brain was studied in adult male rats, fed a diet containing 8.7, 17 (control animals), 32 and 51% of protein during 15 days. The caloric intake was nearly equal in all groups. The highest food intake was observed in the animals on the low protein diet. Changes in plasma amino acids were variable. In contrast to the behavior of most amino acids in plasma, the branched chain amino acids were highest in the animals fed the 51% protein diet. Despite the low protein intake in the animals fed a 8.7% protein diet, the concentration of serine, glutamic acid, glutamine, glycine, alanine, methionine, isoleucine, leucine, phenylalanine and ornithine were significantly higher compared to control animals, whereas in those receiving a high protein diet, valine, leucine, tyrosine, tryptophan and histidine increased in relation to the increased protein and amino acid intake. The plasma amino acid patterns are not greatly influenced by the amino acid distribution in the food and the amount ingested. Alanine aminotransferase, aspartate aminotransferase, glutamate dehydrogenase and cholinesterase showed a two- to fivefold increased activity in the liver of animals consuming a high protein diet. In the brain, the concentration of valine, leucine, isoleucine, phenylalanine and tyrosine in animals receiving the low protein diet was higher than in controls and increased further with increasing protein content of the diet. Glutamine was increased in all dietary groups. The predicted influx of amino acids showed increasing influx rates in dependence of the plasma amino acid concentration. The entry of tyrosine and tryptophan and their brain concentration was inversely proportional to the protein content of the diet. In the present study which considers long-term adaptation to an increasing protein and amino acid intake in comparison to a balanced control protein diet, the levels of the indispensable amino acids were maintained within narrow limits in the brain and liver. The results indicate that inspite of a variable protein intake, the body tends to keep organ amino acids in relatively narrow limits favoring in this way amino acid homeostasis.
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PMID:Effect of different protein diets on the distribution of amino acids in plasma, liver and brain in the rat. 159 Jun 69

Alterations of sleep are reported to occur in sudden infant death syndrome (SIDS). It is well established that the hypothalamus mediates the onset, maintenance, and timing of sleep, and does so via serotonergic and cholinergic mechanisms. We have investigated serotonergic and cholinergic synaptic markers in the hypothalamus from eight SIDS infants and six age-matched non-SIDS infants between 3 and 7 months of age. By use of established methods, we observed a number of chemical alterations in SIDS hypothalamus: (1) tryptophan content was increased and serotonin content was decreased, (2) serotonin binding was increased and imipramine binding was unchanged, (3) monoamine oxidase-A activity was increased without an effect on monoamine oxidase-B, and (4) choline acetyltransferase activity was decreased and acetylcholinesterase activity was unchanged.
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PMID:Sudden infant death syndrome: altered aminergic-cholinergic synaptic markers in hypothalamus. 171 64

Heritable neurodegenerative diseases may be associated with one or more endogenous neurotoxins whose actions on neurons lead to the degenerative changes. One metabolite of tryptophan, the amino acid L-kynurenic acid (L-KYN), was chronically injected into the striatum of the male rat to test its potential as an endogenous neurotoxin. L-KYN, at concentrations of approximately five times its normal brain levels, produced a large lesion with relative selective neuron sparing. The L-KYN-induced lesion presented three concentric regions: a central necrotic zone, a thin pyknotic zone, and an outermost spongiose zone. The number of GABA-ergic neurons were markedly reduced (approximately 76%), while cholinesterase-positive neurons were also lost. The NADPH diaphorase-positive neurons were the most resistant to L-KYN neurotoxicity and were spread throughout the spongiose zone. The brain levels of L-KYN are abnormal in patients with the neurodegenerative disorder Huntington's disease and as a neurotoxin L-KYN may play a role in the etiology of this disease. Of further significance, the fact that L-KYN is neurotoxic contraindicates the use of this excitatory amino acid receptor antagonist as a therapeutic agent in the treatment of neurodegenerative disorders.
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PMID:Chronic intrastriatal injection of the excitatory amino acid receptor antagonist L-kynurenic acid in rat produces selective neuron sparing lesions. 173 68

We report Raman spectra of various cholinesterases: lytic tetrameric forms (G4) obtained by tryptic digestion of asymmetric acetylcholinesterase (AChE) from Torpedo californica and Electrophorus electricus, a PI-PLC-treated dimeric form (G2) of AChE from T marmorata, and the soluble tetrameric form (G4) of butyrylcholinesterase (BuChE) from human plasma. The contribution of different types of secondary structure was estimated by analyzing the amide I band, using the method of Williams. The spectra of cholinesterases in 10 mM Tris-HCl (pH 7.0) indicate the presence of both alpha-helices (about 50%) and beta-sheets (about 25%), together with 15% turns and 10% undefined structures. In 20 mM phosphate buffer (pH 7.0), the spectra indicated a smaller contribution of alpha-helical structure (about 35%) and an increased beta-sheet content (from 25 to 35%). This shows that the ionic milieu profoundly affects either the conformation of the protein (AChE activity is known to be sensitive to ionic strength), or the evaluation of secondary structure, or both. In addition, we analyzed vibrations corresponding to the side chains of aromatic and aliphatic amino acids. In particular, the analyses of the tyrosine doublet (830-850 cm-1) and of the tryptophan vibration at 880 cm-1 indicated that these residues are predominantly 'exposed' on the surface of the molecules.
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PMID:A comparative Raman spectroscopic study of cholinesterases. 179 30

A peptide of acetylcholinesterase (AcChoEase; acetylcholine acetylhydrolase, EC 3.1.1.7) from the venom of the cobra Naja naja oxiana labeled by the affinity reagent N,N-dimethyl-2-phenylaziridinium (DPA) has been identified. The sequence is Gly-Ala-Glu-Met-Trp-Asn-Pro-Asn. In AcChoEase from Torpedo californica, a homologous peptide was labeled and isolated. Its sequence is Ser-Gly-Ser-Glu-Met-Trp-Asn-Pro-Asn, representing positions 79 through 87. In both cases labeling can be prevented by 0.1 mM edrophonium, indicating that the respective peptides form part of the anionic subsite of the catalytic center. The modified residue was tryptophan (Trp-84 in Torpedo AcChoEase) in both enzymes. In contrast to AcChoEase from Torpedo, the enzyme from cobra venom does not contain a peripheral anionic binding site.
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PMID:Anionic subsites of the catalytic center of acetylcholinesterase from Torpedo and from cobra venom. 206 91

Hybridomas secreting monoclonal antibodies to Nippostrongylus brasiliensis antigens were generated by hybridization of IR983F myeloma cells with spleen cells from Lou/M/Wol rats infected with living third-stage larvae. Antibodies specific either for larval or worm antigens were identified by enzyme-linked immunosorbent assays with Nippostrongylus brasiliensis fragments, homogenates and secretions as antigens. The results demonstrate that all antibodies which recognized larval antigens (38 antibodies) also reacted with worm surfaces. Ten antibodies were specific only for worm antigens. Ten antibodies reacted with worm homogenate, three antibodies recognized components of worm secretion and 17 antibodies combined with acetylcholinesterase. The epitope specificity was investigated by the capacity of various glycosides, aminoacids, N-acetylneuraminic acid and phosphorylcholine to inhibit the binding to worm fragments. The analysis revealed that alpha-methylglucoside, alpha-methylmannoside, N-acetylglucosamine, N-acetylgalactosamine, fucose and the amino acids leucine, phenylalanine, tyrosine, serine, tryptophan did not combine with the antigen-binding sites of the antibodies. Proline, arginine and histidine, however, displayed inhibitory effects. With N-acetylneuraminic acid as inhibitor three groups of antibodies could be discriminated. At a concentration of 10-20 mM, phosphorylcholine was a potent inhibitor for all antibodies.
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PMID:Characterization of antigens of the nematode Nippostrongylus brasiliensis by monoclonal antibodies. 241 42


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