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 investigated the inhibition of human cholinesterases by galanthamine, an alkaloid of the common snowdrop (galanthus nivalis). In vitro, the compound showed potent enzyme inhibition and 50-fold selectivity for acetylcholinesterase (EC 3.1.1.7) as opposed to butyrylcholinesterase (EC 3.1.1.8). There was no difference between enzyme inhibition by galanthamine in whole blood and separated fractions of plasma and erythrocytes. We conclude that galanthamine does not accumulate in large amounts in red blood cells. In vivo, administration of galanthamine in a healthy volunteer and in a patient who underwent long-term treatment confirmed the selectivity of galanthamine for acetylcholinesterase.
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PMID:Selective inhibition of human acetylcholinesterase by galanthamine in vitro and in vivo. 235

A simple expression describing the relation between the duration of rising phase and amplitude of miniature end-plate currents (MEPC) is suggested. Parameters of MEPC of the rat diaphragm with different degrees of acetylcholinesterase inhibition by galanthamine were used to estimate the lower levels of acetylcholine diffussion coefficient (0.86.10-6 cm2/s) and channel opening rate constant (21000 s-1).
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PMID:[An attempt to estimate various characteristics of neuro-muscular transmission from the rising phase of miniature end-plate currents]. 254 69

The time course of the effects of the long-acting acetylcholinesterase (AChE) inhibitor, galanthamine, on a spatial navigation task and on AChE and acetylcholine (ACh) levels were investigated in mice. Mice received either saline or ibotenic acid injections into the nucleus basalis magnocellularis (nBM). The control and nBM group were than trained to perform a modified Morris swim task and the time to find the hidden platform was recorded. The nBM group took significantly longer to find the platform than the control group in the reversal phase of testing. Galanthamine attenuated the performance deficit in the nBM-lesioned group in a time-dependent manner, with peak performance at four hours after injection of 5.0 mg/kg galanthamine IP. This dose impaired performance of the task in control mice, with the most severe deficits observed at two hours after injections when motor activity was severely reduced. Galanthamine (5.0 mg/kg IP) significantly decreased cortical AChE activity and significantly increased cortical ACh content in control mice in a time-dependent manner. The time courses of the neurochemical effects, however, did not correlate precisely with the behavioral time course. Galanthamine concentrations up to 1 x 10(-5) M did not affect choline acetyltransferase (ChAT) activity, [3H]hemicholinium-3 (HCh-3) binding to the choline carrier, [3H]quinuclidinylbenzilate (QNB) binding to muscarinic receptors, or [3H]acetylcholine binding to nicotinic receptors in cortical homogenates. AChE activity was inhibited by galanthamine in cortical homogenates with an IC50 of 4.1 x 10(-7) M.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Galanthamine, an acetylcholinesterase inhibitor: a time course of the effects on performance and neurochemical parameters in mice. 262 44

Miniature end-plate currents (MEPC) in rat diaphragm were studied with voltage-clamp technique when synaptic acetylcholinesterase (AChE) was inhibited with different concentrations of galanthamine. The MEPC amplitude and time course were increased progressively with galanthamine concentrations in the range of 3.16 X 10(-8) - 10(-6) g/ml. The decay of MEPC was always exponential. The input resistance of muscle fibres increased. Galanthamine (10(-5) g/ml) produced a curare-like action: the amplitude and duration of MEPC were less as compared with those at galanthamine concentration 10(-6) g/ml, the decay of MEPC became biphasic. During washing out of the drug, the duration of MEPC began to increase and then to diminish, returning to the initial value 3 hours later. The decay of MEPC became exponential. A positive correlation was found between half-decay time and amplitude of MEPC both in the presence and in the absence of anticholinesterase. It is supposed that the functional role of synaptic AChE in limiting the postsynaptic effect of acetylcholine is not so significant as it is usually considered, therefore it is possible to use the parameters of MEPC for the estimation of functional AChE activity.
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PMID:[Miniature currents of the endplates of the muscle fibers of the diaphragm of the rat after inhibition of acetylcholinesterase with galanthamine]. 299 23

The effects of the long-acting acetylcholinesterase (AChE) inhibitor, galanthamine, on spatial memory were investigated in mice. Mice received ibotenic acid or sham lesions to the nucleus basalis magnocellularis (nBM). Groups of nBM-lesioned and control mice were then trained on a modified Morris swim maze task. Each mouse was first placed on a platform and then into quadrants of the swim tank in a random order. Time required to find the hidden platform was measured. In different phases of testing, the animal had to find a platform that either remained in the same quadrant (reference memory component) or was moved daily (working memory component). The nBM-lesioned mice took significantly longer to find the platform as compared to controls on the working, but not on the reference, memory component of the task. Galanthamine (5.0 mg/kg, IP), given 3.5 hours before testing, improved performance on the working memory task in nBM-lesioned mice by 70% and strikingly impaired performance in controls. Galanthamine's ability to reverse cognitive deficits induced by nBM lesions and its comparatively long half-life suggest that it may be effective in treating the central cholinergic deficits in Alzheimer's disease patients.
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PMID:A long-acting cholinesterase inhibitor reverses spatial memory deficits in mice. 325 44

Miniature end-plate currents (MEPC) were recorded in voltage clamped muscle fibers of the rat diaphragm at different degrees of acetylcholinesterase (AChE) inhibition with galanthamine. A model has been suggested connecting the increase in MEPC amplitude with the concentration of a competitive reversible AChE inhibitor. Using the model suggested, the changes in the junctional AChE activity inhibited with different concentrations of galanthamine were estimated. The calculated value of the inhibitory galanthamine constant is 2.8 X 10(-7) M.
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PMID:[Quantitative estimation of synaptic acetylcholinesterase inhibition with galanthamine using parameters of miniature endplate currents]. 339 May 82

Desoxypeganine hydrochloride isolated from Peganum harmala L. caused in animals a pronounced depression of cholinesterase activity. By anticholinesterase activity desoxypeganine was ten times superior peganine hydrochloride and 2 times galanthamine hydrochloride. In the experiments on anesthetized cats desoxypeganine hydrochloride eliminated blockade of neuromuscular conductivity induced by diplacine and on the contrary enhanced blockade induced by ditilin. It increases sensitivity to acetylcholine of the straight abdominal muscle of the frog and isolated segments of the small intestine. Desoxypeganine hydrochloride is used for treatment of patients with lesions of the peripheral nervous system.
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PMID:[Pharmacological characteristics of desoxypeganine hydrochloride]. 372 Sep 32

The kindling phenomenon was produced after chronic electrostimulation of the cat amygdala. The duration and intensity of petit mal and grand mal were recorded. The M-cholinomimetic arecoline (0.3 mg/kg), the acetylcholinesterase inhibitor galanthamine (1-3 mg/kg) and the N-cholinergic blockers eterofen (5-10 mg/kg) and ganglerone (035-3.5 mg/kg) intraperitoneally decreased or abolished the kindling phenomenon. Combination of M-cholinomimetics with N-blockers facilitated the anticonvulsant effects. Nicotine (0.5 mg/kg) and the M-cholinergic blocker methylbenactyzine (0.5-1 mg/kg) as well as combination of methylbenactyzine with galanthamine, on the contrary, facilitated and aggravated seizures in cats. In the authors' opinion, the M- and N-cholinergic mechanisms are involved in formation of the kindling phenomenon. It is suggested that N-cholinergic blockers or their combinations with M-cholinomimetics may be used as anticonvulsants.
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PMID:[Participation of m- and n-cholinergic mechanisms in the development of the kindling phenomenon of the amygdala in cats]. 400 13

Presynaptic effect of compound application of the cholinesterase (ChE) inhibitors of the reversible (galanthamine) and the irreversible (armin) after galanthamine pretreatment has been studied on the neuromuscular transmission at the rat diaphragm. The experiment conditions were regarded as a model of the preventive action of the reversible ChE inhibitors against organism poisoning by the irreversible ChE inhibitors. The quantal content of the end plate potentials (EPP) decreases under the compound action of inhibitors. But under these conditions the EPP amplitude at the single nerve stimulation increases as compared with the control one. The pronounced presynaptic depression and the block of the neuromuscular transmission are observed at the repetitive stimulation (10-50 s-1). The preventive action of galanthamine against the armin poisoning does not relate to presynaptic processes.
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PMID:[Joint action of reversible and irreversible cholinesterase inhibitors on neuromuscular transmission in the rat diaphragm]. 631 88

The effects of galanthamine, an alkaloidal anticholinesterase agent whose chemical structure bears similarity to codeine, was studied in various animal and isolated organ tests. Antinociceptive activity of galanthamine given subcutaneously was detected and compared to physostigmine and morphine in the rat hot plate test. Naloxone partially blocked the effect of galanthamine but not that of physostigmine. Both cholinesterase inhibitors provided analgesia in the mouse acetic acid writhing test. They potentiated the effect of morphine in the rat hot plate test but inhibited the barbiturate anaesthesia potentiation of morphine in the rat. While galanthamine provided analgesia in the intact animal, it failed to produce opiate-like activity in such isolated organs as longitudinal muscle strip of the guinea-pig ileum, mouse vas deferens, and cat nictitating membrane.
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PMID:Study of the analgesic effects of galanthamine, a cholinesterase inhibitor. 666 67


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