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 present experiments were performed to investigate the potential role of central adrenergic neurons in regulating occurrence of yawning in rats. Intraperitoneal injection of tacrine (THA) or 9-amino-2,3,5,6,7,8-hexahydro-1H-cyclopenta(b)-quinoline monohydrate HCl (NIK-247), cholinesterase inhibitors, induced yawning, which was markedly increased by pretreatment with the beta-adrenoceptor antagonist, pindolol. The yawning evoked by tacrine or NIK-247 given alone or in combination with pindolol was inhibited by pretreatment with scopolamine but not by mecamylamine or spiperone. Treatment with tacrine or NIK-247 increased acetylcholine content of the striatum, but this effect was not enhanced by pindolol, which per se did not affect basal acetylcholine content. Moreover, pretreatment with the central adrenaline synthesis inhibitors, (+-)-2,3-dichloro-alpha-methylbenzylamine HCl (LY-78335) and 2-cyclooctyl-2-hydroxyethylamine HCl (UK-1187A), increased tacrine-induced yawning. Subcutaneous injection of talipexole (B-HT 920), a dopamine D2 receptor agonist, evoked yawning, which was also increased by pindolol, LY-78335, and UK-1187A. These receptors antagonists and synthesis inhibitors per se did not cause yawning responses. The results suggest that the beta-adrenoceptor blockade and the inhibition of adrenaline synthesis facilitate the occurrence of yawning induced by cholinergic and dopaminergic agonists, and thus the central adrenergic neuronal systems may be implicated in the regulation of yawning responses.
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PMID:Role of adrenergic neuronal activity in the yawning induced by tacrine and NIK-247 in rats. 136 95

The effects of maternal ethanol exposure on neurotransmission and second messenger systems were examined in rats using histochemistry and in vitro autoradiography. Thirty % ethanol was administered to pregnant rats from gestational day 7 to the day of delivery. Quantitative autoradiography was used to map muscarinic cholinergic, dopamine D2, adenosine A1, and inositol 1,4,5-trisphosphate binding sites, as well as to localize adenylate cyclase and protein kinase C. We found no difference in the patterns of staining with acetylcholinesterase and Timm's stain between control and prenatally ethanol-exposed rats on postnatal day (PN) 30. In the ethanol-exposed rats, [3H]forskolin binding sites were increased during early development in the CA1 subfield of the hippocampus and the occipital cortex; [3H]phorbol ester binding sites were increased in the cortex, striatum, and hippocampus; hippocampal muscarinic cholinergic sites were increased on PN4 and 30; adenosine A1 binding was reduced on PN10 in most regions examined, but was increased in the CA1 subfield on PN30; dopamine D2 receptor levels were significantly reduced on PN30 in the striatum; and IP3 receptors were decreased in most regions studied, but particularly in the cerebellum. Thus, some of these changes were transient and others were long-lasting. Although histopathological abnormalities were minimal, the alterations of binding sites in the cerebellum (the coordination center) and in the hippocampus (related to memory and learning) that were detected may contribute to the behavioral and mental deterioration seen in the fetal alcohol syndrome.
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PMID:The effects of maternal ethanol exposure on neurotransmission and second messenger systems: a quantitative autoradiographic study in the rat brain. 166 22

Anti-cholinesterase activity of dopamine D2 receptor antagonist, domperidone was studied by means of chronically implanted force transducers in the gastrointestinal (GI) tract in five conscious dogs. Cisapride was used as a drug to stimulate endogenous release of acetylcholine. In the digestive state, cisapride (0.25 mg/kg) stimulated 18.6 +/- 5.6% increase in the motor index of the gastric antrum alone, however, combined administration with domperidone (1.0 mg/kg-hr) significantly enhanced the motor index in the gastric antrum and duodenum. In the gastric antrum, the increase was 68.1 +/- 7.2%. During the interdigestive state, cisapride did not always induce the interdigestive migrating contractions (IMC)-like contractions in the GI tract, but the background infusion of domperidone significantly increased the incidence of the occurrence of IMC-like contractions by cisapride. In in vitro study, weak but significant anti-cholinesterase activity was found in domperidone, the activity being about 1/1,000 of that of neostigmine. In dog experiment, similar enhancement of motor stimulating activity of cisapride was observed when neostigmine was given at 1.0 micrograms/kg-hr. In conclusion, domperidone has anti-cholinesterase activity and acts to enhance motor stimulating activity of cisapride through inhibition of cholinesterase activity in the upper digestive tract.
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PMID:[Anti-cholinesterase activity of dopamine D2 receptor antagonist: its clinical significance]. 257 86

The expression of mRNA coding for the long (D2L) and short (D2S) isoforms of the dopamine D2 receptor was measured by in situ hybridization histochemistry in embryonic striatal tissue grafts implanted into the ibotenic acid-lesioned neostriatum of adult rats. The intact, lesioned and grafted neostriata were evaluated 3 months after transplantation using 35S-labelled 'antisense' oligonucleotide probes (45-mer) specific for each mRNA isoform. In the adult neostriatum each mRNA isoform exhibited a strong lateral-to-medial gradient in expression in terms of both the number of expressing cells and the hybridization signal (grain density) per cell. Although there were no significant differences in the numbers of cells expressing the two isoforms in each striatal compartment, the hybridization signal per cell for D2S was significantly greater than that for D2L in the lateral and central striatum. The mRNA expression of each isoform was markedly reduced by the lesions. In the striatal grafts, the expression of both D2L and D2S occurred in 'patches' that corresponded to patches of intense acetylcholinesterase activity, and which are believed to involve reaggregation of striatal-like tissues within the graft. In contrast to the situation in the intact neostriatum the striatal grafts contained significantly greater numbers of cells expressing D2S mRNA; however, similar to the findings in the intact striatum the mRNA signal per cell was significantly greater than that for D2L mRNA. These results indicate that the D2 receptor isoforms are differentially expressed in mature striatal tissue grafts, and suggest that the dopamine regulation of striatal grafts via D2 signal transduction mechanisms may be similar to that observed in the normal neostriatum.
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PMID:Localization of the mRNAs for the short and long isoforms of the dopamine D2 receptor in embryonic striatal grafts: predominance of the short isoform. 770 25

Effects of (+/-)-methyl 3-ethyl-2,3,3a,4-tetrahydro-1H-indolo [3,2,1,-de] [1,5] naphthyridine-6-carboxylate hydrochloride (vinconate), an indolonaphthyridine derivative, on the metabolism and function of cerebral cholinergic neurons were investigated using male Wistar rats. Single administration of vinconate (5, 50 and 200 mg/kg) decreased acetylcholine content in the striatum but not those in the cerebral cortex and hippocampus. The same treatment with vinconate (5, 50 and 200 mg/kg, p.o.) had no effect on the activities of choline acetyltransferase and acetylcholinesterase in these brain areas. Although the addition of vinconate (10(-7) - 10(-4) M) had no effect on the high affinity uptake of [3H]choline into striatal slices, it induced a concentration-dependent increase of a KCl(2 x 10(-2) M)-evoked endogenous acetylcholine release. The addition of (-)-sulpiride (10(-8) - 10(-6) M), a dopamine D2 receptor antagonist, also accentuated the KCl(2 x 10(-2) M)-evoked endogenous acetylcholine release form striatal slices. Furthermore, it was found that this (-)-sulpiride (10(-7) M)-induced increase of endogenous acetylcholine release was further augmented by the addition of vinconate (10(-5) M). These results suggest that vinconate may enhance the release of endogenous acetylcholine via the modulation of presynaptic dopamine heteroreceptor in the striatum.
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PMID:Effect of vinconate, an indolonaphthyridine derivative, on metabolism and function of cerebral cholinergic neurons in rat. 825 25

The dose-related effects of the direct dopamine D2 receptor agonist quinpirole [trans-(-)-4aR-4,4a,5,6,7,8,8a,9-octahydro-5-propyl-1 H-pyrazolo[3,4-g]quinoline] on the extracellular concentrations of dopamine and acetylcholine in rat striatum were measured using in vivo microdialysis. Quinpirole was administered intraperitoneally at doses of 3, 30, 300, and 3000 micrograms/kg. Acetylcholine measurements were conducted in the presence of 10 nmol/l of the acetylcholinesterase inhibitor neostigmine in the microdialysis perfusate. The 3 micrograms/kg dose of quinpirole elicited a significant 26% decrease in extracellular dopamine level in striatum whereas the extracellular level of acetylcholine was significantly increased by 15%. At the higher doses tested, quinpirole administration produced significant decreases in the extracellular concentrations of both dopamine and acetylcholine. The maximum inhibition of striatal dopamine efflux by quinpirole was 74% and this effect was observed at the 300 micrograms/kg dose. Inhibition of striatal acetylcholine output reached a maximum of 78% after administration of 3000 micrograms/kg quinpirole. ED50 values (microgram/kg) for quinpirole-induced inhibition of release were 12.4 and 240 for striatal dopamine and acetylcholine, respectively. We conclude from these data that dopamine exerts a tonic inhibitory control over spontaneous acetylcholine efflux in striatum that is directly mediated by dopamine D2 receptors.
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PMID:Spontaneous release of acetylcholine in striatum is preferentially regulated by inhibitory dopamine D2 receptors. 899 8

The cataleptogenic effects of haloperidol, a dopamine D2 receptor antagonist; SCH23390, a D1 receptor antagonist; physostigmine, a cholinesterase inhibitor; and pilocarpine, a muscarinic M1 receptor agonist, were challenged by pretreatment of mice with SKF38393, a dopamine D1 receptor agonist; apomorphine, a dopamine D1/D2 receptor agonist (mainly D2 receptor); pirenzepine, a muscarinic M1 receptor antagonist; and scopolamine, a muscarinic M1/M2 receptor antagonist. The effect of physostigmine and pilocarpine on haloperidol and SCH23390 cataleptic responses was also examined. Each of the challenging agents blocked one or more of the cataleptogenic agents, but only scopolamine blocked all four. Pirenzepine blocked cataleptic responses induced by SCH23390 and pilocarpine, but not those by haloperidol and physostigmine. The results of this study suggest that the action of physostigmine (endogenous acetylcholine) on M2 receptors might be more potent than that on muscarinic M1 receptors. A further interesting observation was that the haloperidol-induced catalepsy was enhanced by physostigmine pretreatment, but not by pilocarpine pretreatment, whereas the SCH23390-induced catalepsy showed the opposite spectrum of enhancement by the two cholinergic agonists. We conclude that, although the four cataleptogenic agents act via the dopaminergic-cholinergic systems, their pharmacological differences may be due largely to the different receptor subtypes that are involved in the mediation of catalepsy produced by each agent. Thus, dopamine receptors not only influence the cholinergic muscarinic receptors, but muscarinic M1 and M2 receptors also might mediate dopamine D1 and D2 receptor responses, respectively. The results suggest that there are, at the least, relationships between muscarinic M1 receptors and dopaminergic D1 receptors, and between muscarinic M2 receptors and dopaminergic D2 receptors. Dopamine D1 and D2 receptors may interact in a synergistic fashion on dopaminergic systems, but act independently of each other in influencing other system such as cholinergic neurons.
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PMID:Dopaminergic and cholinergic interaction in cataleptic responses in mice. 926 77

Subcutaneous administration of amylin (20-40 micrograms/kg) prevented, in a dose-dependent manner, reserpine- and serotonin-induced gastric damage, but the anti-ulcer effect was not present when lesions were induced by pylorus ligation. The protective effect of amylin was inhibited by pretreatment with capsicin as well as CGRP-(8-37), a calcitonin gene-related peptide (CGRP) and amylin receptor antagonist, and was significantly reduced by domperidone, a dopamine D2 receptor antagonist, or neostigmine, an inhibitor of acetylcholinesterase. Our data suggest that the gastroprotective activity of amylin in some experimental models of gastric ulcers involves capsaicin-sensitive fibers and CGRP receptors. Moreover, the peptide interferes, at least in part, with the dopaminergic and parasympathetic systems.
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PMID:Effect of amylin in various experimental models of gastric ulcer. 928 23

Derivatives of the muscarinic antagonist 3-quinuclidinyl-4-iodobenzilate (QNB), particularly [123I]-(R,R)-I-QNB, are currently being assessed as in vivo ligands to monitor muscarinic receptors in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), relating changes to disease symptoms and to treatment response with cholinergic medication. To assist in the evaluation of in vivo binding, muscarinic receptor density in post-mortem human brain was measured by autoradiography with [125I]-(R,R)-I-QNB and [125I]-(R,S)-I-QNB and compared to M1 ([3H]pirenzepine) and M2 and M4 ([3H]AF-DX 384) receptor binding. Binding was calculated in tissue containing striatum, globus pallidus (GPe), claustrum, and cingulate and insula cortex, in cases of AD, DLB, Parkinson's disease (PD) and normal elderly controls. Pirenzepine, AF-DX 384 and (R,S)-I-QNB binding in the striatum correlated positively with increased Alzheimer-type pathology, and AF-DX 384 and (R,R)-I-QNB cortical binding correlated positively with increased Lewy body (LB) pathology; however, striatal pirenzepine binding correlated negatively with cortical LB pathology. M1 receptors were significantly reduced in striatum in DLB compared to AD, PD, and controls and there was a significant correlation between M1 and dopamine D2 receptor densities. [3H]AF-DX 384 binding was higher in the striatum and GPe in AD. Binding of [125I]-(R,R)-I-QNB, which may reflect increased muscarinic M4 receptors, was higher in cortex and claustrum in DLB and AD. [125I]-(R,S)-I-QNB binding was higher in the GPe in AD. Low M1 and D2 receptors in DLB imply altered regulation of the striatal projection neurons which express these receptors. Low density of striatal M1 receptors may relate to the extent of movement disorder in DLB, and to a reduced risk of parkinsonism with acetylcholinesterase inhibition.
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PMID:Muscarinic receptors in basal ganglia in dementia with Lewy bodies, Parkinson's disease and Alzheimer's disease. 1270 4

We have previously found that synaptic pathway from the basolateral amygdala (BLA) to the dentate gyrus (DG) displays N-methyl-D-aspartate (NMDA) receptor-independent form of long-term potentiation (LTP), which should be a valuable model for elucidating neural mechanisms linking emotion and memory. To explore its cellular mechanisms, we investigated possible involvement of the beta-adrenergic, muscarinic cholinergic and dopaminergic systems on LTP in this pathway of anesthetized rats. The induction of BLA-DG LTP was not affected by administration of the beta-adrenoceptor antagonist propranolol (50-150nmol, i.c.v.), the muscarinic receptor antagonist scopolamine (2-6mg/kg, i.p.), the cholinesterase inhibitor physostigmine (50 nmol, i.c.v.) or the dopamine D(1) receptor antagonist SCH23390 (100nmol, i.c.v.), but significantly inhibited by the dopamine D2 receptor antagonists, chlorpromazine (15nmol, i.c.v.) and haloperidol (0.15-0.5mg/kg, i.p.), and significantly promoted by the dopamine D2 receptor agonist quinpirole (78nmol, i.c.v.). Furthermore, lesioning with 6-hydroxydopamine of the ventral tegmental area (VTA), the origin of mesolimbic dopaminergic neurons, resulted in attenuated BLA-DG LTP. These results suggest that the D2-dopaminergic system, but not the beta-adrenergic, muscarinic or D1-dopaminergic system, is involved in the induction of BLA-DG LTP. In addition, inhibition of BLA-DG LTP by haloperidol or VTA lesion was abolished by blockade of GABAergic inhibition with picrotoxin. It is probable that the D2-dopaminergic system promotes the induction of BLA-DG LTP by suppressing GABAergic inhibition.
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PMID:Involvement of dopamine D2 receptors in the induction of long-term potentiation in the basolateral amygdala-dentate gyrus pathway of anesthetized rats. 1883 99


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