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)

Cholinesterase activities in the hearts and ganglia of an oyster (Crassostrea virginica) and a venerid clam (Macrocallista nimbosa) were measured and compared. Tissue extracts were partially purified by ammonium sulfate fractionation followed by gel column chromatography. Enzymatic activity was assayed spectrophotometrically; substrates were acetyl-, butyryl-, and propionylthiocholine (ATC, BTC, PTC). Kinetic constants characterizing each enzyme were derived. At all substrate concentrations, the hydrolysis rates of both clam enzymes were in the order: BTC greater than PTC greater than ATC. With oyster enzymes the ranking was ATC greater than or equal to PTC greater BTC. The specific activities of oyster heart and ganglion enzymes were similar. In contrast, clam ganglion extracts were 75-100 times more active than clam heart extracts and, with any substrate, had greater activity than either oyster enzyme. All enzyme preparations proved to be homogeneous on the bases of constant substrate activity ratios in successive column fractions, and of intermediate velocities with mixed substrates. Six cholinesterase inhibitors were tested. The specific acetylcholinesterase antagonist, B.W. 62C47, WAS MUCH MORE EFFECTIVE AGAINST OYSTER ENZYMES, WHILE THE SPECIFIC ANTIBUTYRYLCHOLINESTERASE, ISO-OMPA, almost totally inhibited calm enzyme activity, but had little effect on oyster. Eserine was the most effective inhibitor of both enzymes. In conclusion, the enzymes in oyster tissues are acetylcholinesterases, while clam enzymes are butyrylcholinesterases. Nevertheless, clam ganglion esterase is sifficiently active to hydrolyze the physiological substrate, acetylcholine. These results explain the long-observed differences in isolated heart pharmacology between ostreid and venerid bivalves.
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PMID:A comparison of the cholinesterases of an oyster (Crassostrea virginica) and a clam (Macrocallista nimbosa). 1 Mar 39

We developed a new assay for plasma or serum G4 acetylcholinesterase (AChE) activity. There was no difference in G4 AChE activity between serum and plasma. Plasma AChE activity in control subjects (8-92 years) was independent of age. Serum G4 AChE activity was significantly increased in patients with vascular dementia (P less than 0.01), compared with age-matched control, and significantly decreased in those with probable Alzheimer-type dementia (P less than 0.02). The difference between VD and ATD was significant (P less than 0.001), and thus the measurement of plasma or serum G4 AChE activity would be helpful in the differential diagnosis of dementia.
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PMID:Plasma and serum G4 isoenzyme of acetylcholinesterase in patients with Alzheimer-type dementia and vascular dementia. 240 32

Since the function of the brain is considered to be a sum of synaptic transmission phenomena, information on both neurotransmitters and receptors are needed. In addition, experiments of behavioral pharmacology to determine whether the neuron network is in operation or not are indispensable. Acetylcholine (ACh) is difficult to measure in the postmortem brain because of rapid postmortem degradation, and thus the activity of choline acetyltransferase (CAT), a synthetic enzyme, is determined. Receptors for ACh system are classified into muscarinic ACh receptors (MCR) and nicotinic ACh receptors (NCR). Since ACh and MCR/NCR are contained in different neurons, their regional distributions mismatch. Therefore, to evaluate the relationship between the ACh neuronal system and aging or dementia, information on all steps of CAT, receptors, memory and learning experiments are needed. Both in the normally aged brain and ATD brain, the ACh neuronal system at all steps is decreased except an increase in ACh degradation enzyme (acetylcholinesterase) in the normally aged brain. In animals, the decreased ACh neural system associated with aging can be normalized by drugs, showing that the aged brain still has plasticity. On the other hand, autoradiography of MCR in the ATD brain demonstrated destruction of the laminar structure of the cerebral cortex. This suggests that drugs to increase only ACh are not effective for treating ATD. In ATD, treatment methods that prevents structural destruction or its progression should be developed.
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PMID:[Central acetylcholinergic systems in the normal aged and in the patient with Alzheimer-type dementia (ATD)]. 269 98

Pyroglutamyl-ended forms of amyloid-beta-peptide are present in senile plaques in some individuals with Alzheimer type dementia. Single oral administration of the acetylcholinesterase inhibitor SDZ ENA 713 (rivastigmine (+)-(S)-N-ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenylcarbamate hydrogen tartrate) increases basal and K(+)-stimulated pyrrolidone carboxyl peptidase (Pcp) activity in mice frontal cortex synaptosomes in a dose-dependent manner. These results suggest that this drug may ameliorate ATD cognitive deficits acting not only facilitating cholinergic transmission but also avoiding the formation of pyroglutamyl-ended amyloid-beta-peptides (A beta pE) deposition through the activation of Pcp.
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PMID:Acetylcholinesterase inhibitor SDZ ENA 713 (Rivastigmine) increases brain pyrrolidone carboxyl peptidase activity. 1159 25

During the last decade, there has been an explosive growth of research concerning the extract of Ginkgo biloba termed Egb 761. In experimental studies, animal studies and clinical studies Ginkgo biloba has shown a similar pharmacological potency and clinical efficacy like synthetic defined drugs in the therapy of reduced cerebral performance. Ginkgo biloba special extract Egb 761 is a standardized and highly purified extract of Ginkgo leaves. Among the active constituents are the ginkgo-flavone glycosides and the terpene-lactones (ginkgolides, bilobalide). The multifactorial principle of action of Ginkgo biloba is characterized by rheological and blood-flow-promoting properties, protective effects against ischaemia and hypoxia, effects on nerve cell energy metabolism, antioedematous and myelin-protective effects, radical-scavenger activity, effects on various cerebral transmitter and receptor systems. These action principles constitute the rationale for clinical trials in vascular dementia and primary degenerative dementia of the Alzheimer type, and in mixed forms of both. The cerebral bioavailability of Ginkgo biloba extract has been demonstrated by electroencephalography. In clinical trials of different working-groups, effects of Ginkgo biloba on the cognitive performance, global function, and activities of the daily living have been found. Metaanalysis in the indication--demential disorders--comparing Ginkgo biloba versus acetylcholinesterase inhibitors have shown a similar clinical efficacy of both therapy regimens with an additional drug safety benefit for Ginkgo. Due to the clinical efficacy the WHO accepted Ginkgo biloba as an antidementiv drug and add it in January 2000 into the recent ATC-Classification Index. In future antidementive therapy drugs with an different mode of action should be given in combination. Furthermore clinical trials with fixed combinations of acetylcholinesterase inhibitors with Ginkgo biloba extracts in moderate or severe dementia would be necessary.
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PMID:[Value of Ginkgo biloba in treatment of Alzheimer dementia]. 1224 90

A resorufin derivative with a DBS group (probe 1) was designed and investigated for the detection of acetylcholinesterase (AChE) and inhibitor screening. The new assay is based on cascade enzymatic and chemical reactions of ATC, AChE and probe 1, and it can be carried out in a dual-signal detection mode. Moreover, the results show that probe 1 can be used for cell fluorescence staining.
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PMID:A naked-eye visible and fluorescence "turn-on" probe for acetyl-cholinesterase assay and thiols as well as imaging of living cells. 2092 40