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 levels of norepinephrine, dopamine and 5-hydroxytryptamine in brain homogenates of vitamin B12-deficient rats have been investigated. The norepinephrine levels were significantly decreased in the deficient animals compared to controls. The two major catabolic pathways of norepinephrine e.g. monoamine oxidase and catechol-O-methyl transferase did not show significant variations. Both acetyl cholinesterase and butiryl-cholinesterase markedly decreased in the plasma of the vitamin B12-deficient rats.
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PMID:Levels of neurotransmitters in brain of vitamin B12 deficient rats. 1 22

The ultrastructure of neuromuscular junctions in various organs of a starfish and a holothurian was studied. All neurons were found to contain large (100-250 nm), dense-core vesicles. Cytochemical tests for acetylcholinesterase were negative for these neurons. The presence of proteinaceous neurosecretory material was contested by enzymatic digestion (pepsin) which did not attack the dense-core vesicles, as well as by incubation in phosphotungstic acid (PTA) which did not stain these structures. Staining with dichromate produced a positive reaction for 5-hydroxytryptamine. In the absence of synaptic modifications even after specific staining with PTA, the transmission of nervous impulses is effectuated through exocytosis of 5-hydroxytryptamine at nerve endings in the muscle tissue.
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PMID:An ultrastructural and cytochemical study of neuromuscular junctions in echinoderms. 5 43

Acetate esters, such as aspirin methylester, aspirin and resorcinol monoacetate, induced contractions of guinea-pig ileum. Their actions were selectively antagonized by atropine, but were not affected by ganglion blocking agents, conduction blockers, aging with cooling, anoxia or antihistaminics. On the other hand, N-acetates, such as acetanilide and p-acetaminophenol, and no contractile action on the ileum. These acetate esters thus seemed to have a cholinergic action, and not a direct action on muscle or other known specific receptors for endogenous active substances. The contractions induced by the acetate esters were selectively potentiated by low concentrations of choline, whereas those induced by acetylcholine, nicotine, 5-hydroxytryptamine and histamine were not. However, N-acetates did not induce the contractions even in the presence of choline. Organophosphorus cholinesterase inhibitors, such as diisopropyl fluorophosphate and paraoxon, selectively and irreversibly inhibited the actions of aspirin and N,O-diacetyl-p-aminophenol with or without choline. From these results, it is concluded that the acetate esters with or without choline act through the cholinergic system. However, their actions cannot be explained in terms of known mechanisms, such as acetylcholine release, cholinesterase inhibition or a direct muscarinic action. Therefore, the acetate esters, including phenyl acetate which was supposed to be a releaser of acetylcholine, seem to have a hitherto undescribed type of cholinergic action whose mechanism is unknown. It seems that organophosphate-sensitive esterase(s) in the preparation may be essential for initiation of the actions of the acetate esters with or without choline, but the mechanism of the effect of choline is unknown.
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PMID:Aspects of the spasmogenic effects of acetate esters on ileal smooth muscle. 85 12

Hycanthone has a variety of effects on muscular activity and neurotransmitter systems of schistosomes. These include interference with neuronal storage of 5-hydroxytryptamine (5-HT), an increase in the length of schistosomes, a weak stimulation of motor activity, and an inhibition of acetylcholinesterase activity. However, the findings reported in this paper indicate that none of these effects can be related to the mode of the antischistosomal action of hycanthone because (a) these effects are observable only after, but not prior to, the hepatic shift, (b) they are not demonstrable with anti-schistosomal strucutral analogs of hycanthone, or (c) the same effects are elicited in hycanthone-resistant schistosomes. Dansyl choline, under conditions recommended by others, does not stain selectively neuronal structures of schistosomes, but such structures can be visualized under different conditions. However, this stain lacks specificity for cholinergic neurons or receptors because no cholinergic drug can block binding of dansyl choline and because the same fluorescence staining effects are observed with dansic acid and dansyl chloride.
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PMID:Effects of hycanthone on neuromuscular systems of Schistoma mansoni. 87 Jun 66

Effects of chronic (45 days) treatment with different doses of cadmium chloride (0.25 and 1.0 mg/kg/day), methylmercury chloride (0.4 and 4.0 mg/kg/day) and lead acetate (0.2 and 1.0 mg/kg/day) and of 28-day withdrawal of treatment on the levels of acetylcholine (ACh) and activity of acetylcholinesterase (AChE) in cerebral cortex, and concentration of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) in brain-stem were examined in rats. Exposure to both cadmium and methylmercury produced significant decreases in cortical ACh and brain-stem 5-HT levels. In addition, brain-stem NE concentration was increased in methylmercury-treated rats. In contrast, chronic treatment with lead resulted in enhanced cerebrocortical ACh levels but a decreased brain-stem NE concentration. Treatment with cadmium also produced a transient enhancement of striatal dopamine levels. Cadmium-induced decrease in brain-stem 5-HT and lead-induced accumulation of cortical ACh persisted even after 28 day withdrawal of treatment. The data indicate that chronic exposure to low doses of heavy metals produces differential changes in regional levels of various brain biogenic amines. These changes may represent the early signs of adverse effects on CNS function since they occur before any overt symptoms of neurotoxic effects of heavy metals become apparent.
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PMID:Effects of chronic exposure to cadmium, lead and mercury of brain biogenic amines in the rat. 99 61

On the basis of structural relationships between 5-hydroxytryptamine (5-HT, serotonine) and eserine, the effect of 5-HT on partially purified brain cholinesterase (ChE) was studied. The addition of 5-HT to brain ChE in vitro resulted in its inhibition, and the constants characterizing this inhibition, namely, the inhibition rate ki (5.44 X 10(2) mol-1/l - min-1), the equilibrium constant K (1.86 X 10(-3), and the rate constant for spontaneous reactivation kr (1.01 min-1) were determined. The inhibition of AChE by 5-HT in vitro was found to be of the competitive type.
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PMID:Inhibition of cholinesterase by 5-hydroxytryptamine. 124 80

The effects of some muscarinic M1 and M2 receptor agonists and antagonists on rat brain serotonergic activity was assessed by noting their effects on the levels of 5-hydroxytryptamine (5-HT) and its major metabolite, 5-hydroxyindole acetic acid (5-HIAA), estimated by a high pressure-liquid chromatographic (HPLC) technique. The muscarinic M1 receptor agonists, arecholine and McN-A-343, and the M2 receptor agonists, gallamine and AF-DX 116, induced a dose-related decrease in the concentrations of both 5-HT and 5-HIAA. On the contrary, scopolamine and the selective M1 receptor antagonist, pirenzepine, increased the levels of the amine and its metabolite. The anti-cholinesterase agent, physostigmine, and the putative M2 receptor agonist, carbachol, induced a dose-related dual effect, with the smaller doses decreasing and the higher doses increasing 5-HT and 5-HIAA concentrations. The results indicate that an inverse relationship exists between the cholinergic and serotonergic neurotransmitter systems in the rat brain due to the likely presence of muscarinic heteroreceptors on serotonergic neurones. The data also indicates that though physostigmine and carbachol may function as M2 receptor agonists, they lose their receptor specificity on dose increment.
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PMID:Effects of muscarinic receptor agonists and antagonists on rat brain serotonergic activity. 128 83

Previous investigators have detected unknown oxidized forms of 5-hydroxytryptamine (5-HT) in the CSF of Alzheimer's disease (AD) patients. Furthermore, an unidentified autoxidation product of this neurotransmitter is an inhibitor of acetylcholinesterase (AChE), an enzyme compromised in the Alzheimer brain. In this study it is demonstrated that the major product of autoxidation of 5-HT is 5,5'-dihydroxy-4,4'-bitryptamine (DHBT). Central administration of DHBT to mice at a dose of 40 micrograms (free base) evokes profound behavioral responses, which persist until the animals die (approximately 24 h). One hour after central administration of DHBT, the levels of norepinephrine, dopamine, 5-HT, and acetylcholine and their metabolites in whole brain are greatly elevated. Disturbances to the catecholaminergic and serotonergic systems were still evident shortly before the death of animals. DHBT is also shown to be a noncompetitive inhibitor of AChE in vitro. These observations suggest that if DHBT is formed as an aberrant metabolite of 5-HT in the human brain, it could potentially be neurotoxic and contribute to the neuronal degeneration and other neurochemical and neurobiochemical changes associated with AD or perhaps other neurodegenerative diseases.
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PMID:5,5'-Dihydroxy-4,4'-bitryptamine: a potentially aberrant, neurotoxic metabolite of serotonin. 135 95

This study is focused on the survival of fetal neocortical grafts placed in the infarcted adult host cortex of the spontaneously hypertensive rat and describes the ability of host axonal regeneration into the graft after a focal ischaemic lesion. Five to seven days following ligation of the right middle cerebral artery, dissociated neocortical primordium from fetuses of gestational age 12-18 days was implanted into the infarcted cortical area. Surviving transplants were seen in all rats, although grafts derived from gestational age 12-14 days displayed an irregular morphology rich in sinusoid-like cavities and containing fewer cells of apparently mature neuronal morphology. Grafts from older donors contained perikarya of neuronal appearance; however, they lacked normal cortical lamination. Ten days postgrafting, fibers stained by acetylcholinesterase histochemistry, dopamine-beta-hydroxylase, and 5-hydroxytryptamine immunohistochemistry were found in the grafts, and by 10-23 weeks after transplantation the fiber density had increased substantially. When the retrograde tracer Fluoro-Gold was injected into the grafted tissue, labeled cells were found in several subcortical nuclei of the host, including the nucleus basalis of Meynert, ventral pallidum, thalamus, dorsal raphe, locus coeruleus, as well as the ipsilateral and contralateral neocortex. This study shows that grafts of dissociated neocortical tissue exhibit good survival and growth potential when implanted into infarcted neocortex and that several nerve fiber systems of the adult host have a regenerative capacity sufficient to innervate the grafted tissue.
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PMID:Fetal neocortical grafts implanted in adult hypertensive rats with cortical infarcts following a middle cerebral artery occlusion: ingrowth of afferent fibers from the host brain. 157 19

Different regions of the prostate gland, namely prostatic capsule, peripheral prostate and central prostate (subdivided into proximal (near the bladder neck), distal (near the verumontanum) and midway between these areas) were obtained from 32 obstructed (stable obstructed, n = 8; unstable obstructed, n = 13; acute retention, n = 11) and five control patients. The innervation of these tissues was studied both histochemically to localise acetylcholinesterase activity and immunohistochemically for dopamine-beta-hydroxylase, 5-hydroxytryptamine, vasoactive intestinal polypeptide, neuropeptide Y, leu- and met-enkephalin, calcitonin gene-related peptide, substance P and somatostatin. In control patients the greatest density of nerves was found in the proximal central prostate, followed by the anterior capsule and distal central prostate, with the least density in the peripheral prostate. The greatest density of nerves were acetylcholinesterase positive and immunoreactive to neuropeptide Y followed (in decreasing order) by nerves immunoreactive to: vasoactive intestinal polypeptide and dopamine beta-hydroxylase; leu-enkephalin and 5-hydroxytryptamine; calcitonin gene-related peptide; met-enkephalin; substance P; somatostatin. In addition a group of periacinar 5-hydroxytryptamine-immunoreactive cells and ganglia containing acetylcholinesterase, dopamine beta-hydroxylase and all of the peptides studied except somatostatin were identified. In the prostate gland from obstructed patients there was a significant reduction in the density of acetylcholinesterase-positive nerves (p less than 0.001) when compared with the controls. A similar trend was found for dopamine beta-hydroxylase, 5-hydroxytryptamine and all of the putative neuropeptides in most areas of the prostate, the most notable exceptions being in the peripheral prostate, with an increase in dopamine beta-hydroxylase- and leu-enkephalin-immunoreactive nerves in all three groups of obstructed patients an an increase in vasoactive intestinal polypeptide- and calcitonin gene-related peptide-immunoreactive nerves in those presenting in urinary retention. The functional significance of these findings is discussed.
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PMID:The innervation of the human prostate gland--the changes associated with benign enlargement. 171 53


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