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)

Pyridostigmine 0.143 mg kg-1 (maximum 10 mg) and atropine 0.0143 mg kg-1 (maximum 1 mg) were administered i.v. to six healthy male volunteers. Peripheral venous blood samples were drawn for measurement of serum cholinesterase activity. Maximum inhibition of the enzyme was found 5 min after injection with a decrease to 27 +/- 5% (mean +/- SEM) of the original activity. Forced expiratory volume in the first 1s (FEV1) was measured at fixed time intervals for 90 min. No decrease in FEV1 was observed; on the contrary, there was a small increase. We conclude that atropine effectively antagonizes the muscarinic side-effects of pyridostigmine on bronchial smooth muscle tone and bronchial secretions, when administered in clinical doses to normal human subjects.
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PMID:Effect of a mixture of pyridostigmine and atropine on forced expiratory volume (FEV1), and serum cholinesterase activity in normal subjects. 397 Aug

Three types of immature megakaryocytes, detected by their morphological properties, have been characterized in bone marrow of normal C57BL/6 mice. Morphological classification of these cells was carried out by determining (1) presence and relative amount of acetylcholinesterase, (2) cell size, (3) nuclear/cytoplasm ratio, and (4) nuclear shape. The immature megakaryocytes were classified as: (A) cells distinguished by a round nucleus (10.6 +/- 1.1 mu diameter; mean +/- SEM), which had the highest nucleus / cytoplasm ratio and lowest content of acetylcholinesterase; (B) cells with an indented nucleus (13.0 +/- 1.9 mu diameter), which had increased acetylcholinesterase content and reduced nucleus/cytoplasm ratio compared to the round-nucleus cell type; and (C) lobed-nucleus cells (14.5 +/- 2.9 mu diameter), which showed further increase in acetylcholinesterase content and reduction in nucleus/cytoplasm ratio. Increased numbers of immature megakaryocytes were detected, indicating that a proportion of these cells are undetected using conventional staining techniques. Based on the observed alterations in size, acetylcholinesterase content, and nuclear complexity, it was concluded that these cells constitute part of a progressive maturation sequence intermediate between the progenitor cell (CFU-Mk) and mature easily recognizable megakaryocytes.
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PMID:Immature Megakaryocytes in the Mouse: Morphology and quantitation by acetylcholinesterase staining. 617 Mar 67

In a survey of 21 patients with myasthenia gravis receiving regular acetylcholinesterase inhibitor therapy, 8 were found to have air-flow limitation associated with their antimyasthenic therapy. In 6 of these subjects, detailed assessments were made of the effect of antimyasthenic therapy on airways function. Pyridostigmine was given together with either placebo or the anticholinergic bronchodilator ipratropium bromide (72 micrograms) by inhalation administered double blind on 2 consecutive days. Airways resistance (Raw) increased significantly after pyridostigmine and placebo inhaler (0.49 +/- 0.13 kPa/L/s basal versus 0.60 +/- 0.13 kPa/L/s at 2 h; mean +/- SEM, p less than 0.05), whereas a significant decrease in Raw followed the combination of pyridostigmine with ipratropium bromide (0.57 +/- 0.08 kPa/L/s basal versus 0.41 +/- 0.07 kPa/L/s at 2 h, p less than 0.05). Thus, acetylcholinesterase inhibitor therapy in subjects with myasthenia gravis with airflow limitation led to significant increase in airways resistance that could be completely reversed by the inhalation of the muscarinic receptor blocker ipratropium bromide.
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PMID:Air-flow limitation in myasthenia gravis. The effect of acetylcholinesterase inhibitor therapy on air-flow limitation. 622 24

Acetylcholine metabolism has been studied in primary cultures of neurons dissociated from newborn rat nodose ganglia. Neither nerve growth factor nor muscle-conditioned medium had any detectable effect on the long-term survival of these neurons, which appeared well differentiated upon phase-contrast and electron microscopic examination. [3H]Acetylcholine synthesis and accumulation by 2-3-week old nodose cultures and choline acetyltransferase activity were increased (2.0 +/- 0.15)-fold and (2.0 +/- 0.48)-fold, respectively, upon growth with muscle-conditioned medium, whereas acetylcholinesterase was decreased (1.5 +/- 0.1)-fold (means +/- SEM, n = 5-9). The same effects were observed when comparing nodose cultures grown in the presence of proteins purified from conditioned medium in four fractionation steps. This purified material had no effects on the protein content of the cultures, or on lactate dehydrogenase activity, and thus did not affect the overall growth of the cultures. We demonstrate that this factor copurifies with a factor(s) involved in the regulation of choline acetyltransferase and acetylcholinesterase in neuron cultures from newborn rat superior cervical ganglia [Swerts, Le Van Thai, Vigny and Weber (1983) Devl Biol. 100, 1-11] and from embryonic day 13 rat embryo spinal cord [Giess and Weber (1984) J. Neurosci. 4, 1442-1452]. Although the cholinergic factor from muscle-conditioned medium has not been purified to homogeneity, the data suggest that the same extracellular, macromolecular factor may be involved in the regulation of acetylcholine metabolism in derivatives from the neural crest, the neural tube and the epibranchial placodes.
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PMID:Acetylcholine metabolism by cultured neurons from rat nodose ganglia: regulation by a macromolecule from muscle-conditioned medium. 652 96

The extensor digitorum longus muscles of rat were stained for the localization of acetylcholinesterase activity at the neuromuscular junctions. The modified methods of Koelle-Friedenwald and Karnovsky-Roots were used with acetylthiocholine iodide as the substrate. The merits and demerits of both these methods are discussed. TEM and SEM X-ray dispersive analyses of the muscle fibres treated histochemically by both the methods were also made in order to elucidate further the nature of the reaction products. Denervated muscles were subjected to similar treatment.
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PMID:Thiocholine methods for the demonstration of acetylcholinesterase in neuromuscular junctions. 727 52

Eptastigmine is a long-lasting acetyl-cholinesterase inhibitor, currently being developed for the symptomatic treatment of Alzheimer's disease. In the present study, we investigated the relationship between pharmacokinetics and pharmacodynamics of eptastigmine in young healthy volunteers. Eight male subjects received single oral doses of 10, 20, and 30 mg of eptastigmine and placebo according to a double-blind, randomized, crossover design. Blood was collected before and 0.5, 1, 1.5, 2, 3, 4, 6, and 24 hours after drug administration. Cholinesterase activity was measured using a potentiometric method in both plasma (butyryl-cholinesterase) and in red blood cells (acetyl-cholinesterase). Eptastigmine plasma levels were measured by a very sensitive high-performance liquid chromatography method (limit of quantitation 0.2 ng/mL). Eptastigmine plasma concentrations increased proportionally with the dose (mean +/- SEM AUC0-24 was 0.74 +/- 0.58, 3.61 +/- 1.15, and 6.25 +/- 1.51 ng.h/mL with 10, 20, and 30 mg, respectively) and were undetectable at 24 hours. The inhibition of acetyl-cholinesterase was dose-dependent (peak inhibition was 15 +/- 2%, 30 +/- 4%, and 36 +/- 6% with 10, 20, and 30 mg, respectively) and long-lasting, with a residual inhibition of 8 to 11% at 24 hours. Acetyl-cholinesterase inhibition and drug plasma levels were related over time with a counterclockwise hysteresis curve, suggesting the formation of active metabolites and/or a slow association to and dissociation from the enzyme in red blood cells. Butyryl-cholinesterase inhibition was weak and not dose-dependent (peak inhibition was 12 +/- 4%, 13 +/- 3%, and 12 +/- 2% with 10, 20, and 30 mg, respectively). The drug was well tolerated by all subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship between pharmacokinetics and pharmacodynamics of eptastigmine in young healthy volunteers. 760 18

1. NG-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor) inhibits vasodilator responses to acetylcholine but not methacholine in human forearm vasculature. To investigate whether this difference results from the relative susceptibility of these agonists to hydrolysis by acetylcholinesterase, we studied vasodilator responses to brachial artery administration of acetylcholine alone and in the presence of the acetylcholinesterase inhibitor edrophonium. 2. Vasodilator responses to constant-rate brachial artery infusions of acetylcholine were biphasic, with an initial peak response fading over 2 min to a plateau. Fade [(peak-plateau)/peak x 100%] was dose dependent (P < 0.02), ranging from 43 +/- 7% (mean +/- SEM) at low dose (16 nmol/min) to 9 +/- 8% at high dose (83 nmol/min). 3. Edrophonium (0.5 mumol/min intra-arterially) alone produced no change in forearm blood flow but increased blood flow responses to acetylcholine (P < 0.01), causing an approximately 10-fold reduction in the dose required to increase plateau blood flow by 10 ml min-1 100 ml-1. 4. Responses to low doses of acetylcholine alone (16 and 41 nmol/min) faded more (P < 0.01) than those to doses of acetylcholine with edrophonium chosen to produce similar plateau blood flows. Responses to acetylcholine (41 nmol/min) also faded more (P < 0.01) than those to methacholine (5 nmol/min), producing matched plateau flows. 5. Peak and plateau responses to acetylcholine (41 nmol/min) were reduced (P < 0.01) by similar amounts (47 +/- 15%, and 37 +/- 13% respectively, P = 0.39) by coinfusion of L/NMMA (4 mumol/min).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibition of acetylcholinesterase selectively potentiates NG-monomethyl-L-arginine-resistant actions of acetylcholine in human forearm vasculature. 770 91

The effects of the centrally acting cholinesterase (ChE) inhibitors, tetrahydroaminoacridine (THA) and E2020 (1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl] methylpiperidine hydrochloride), potential drugs for the treatment of senile dementia, on the basal extracellular acetylcholine (ACh) concentration in the hippocampus of freely moving rats, were determined using a microdialysis technique without the use of a ChE inhibitor in the perfusion fluid and a sensitive RIA. The mean (+/- SEM) basal ACh content in the perfusate was 103.1 +/- 3.6 fmol/sample collected over 30 min when microdialysis probes with a length of 3 mm dialysis membrane were used. The content of ACh decreased to an almost undetectable level upon perfusion of magnesium, suggesting that, in the present study, most of the ACh detected in the perfusates was due to cholinergic neuronal activity. THA (1.65 mg/kg, i.p.) produced an insignificant increase in the extracellular ACh concentration, but a dose of 5 mg/kg, i.p. caused a prolonged and significant 5.5-fold increase from the control value. E2020 (0.65 and 2 mg/kg, i.p.) produced significant, prolonged and dose-dependent increases (4 and 12 times the control value, respectively), the peak effect occurring within 1 h. Perfusion with 10 mumol/l physostigmine produced an about 30-fold increase of ACh output, suggesting that the basal extracellular ACh concentration is highly dependent on ChE activity. When ChE was inhibited locally by perfusion with physostigmine, THA (5 mg/kg) produced a transient and, at its maximum, a 1.42-fold increase in extracellular ACh concentration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of the centrally acting cholinesterase inhibitors tetrahydroaminoacridine and E2020 on the basal concentration of extracellular acetylcholine in the hippocampus of freely moving rats. 787 Jan 92

Protein S is a vitamin K-dependent glycoprotein acting as a cofactor for activated protein C and thereby exerting an antithrombotic effect. When compared to values recorded in the 10 healthy normal weight normolipidemic control subjects (80.1% +/- 5.16; mean +/- SEM), plasma protein S-antigen (PS:Ag) level was found to be significantly (p < 0.01) decreased in the 11 patients with decompensated cirrhosis of the liver (54.72% +/- 4.89) and in the 12 surgical patients in critical condition (59.2 +/- 4.96), while obviously (p < 0.001) increased plasma levels were noted in the group including 20 overweight and hyperlipidemic subjects (113% +/- 3.1). Since the low PS:Ag level was associated with a decreased serum cholinesterase (CHE) activity, while both plasma PS:Ag and serum CHE activity were increased in overweight and hyperlipidemic subjects it is considered that impaired or respectively enhanced hepatic protein synthesis is at least partially responsible for changes affecting this antithrombotic plasma protein.
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PMID:Plasma protein S-antigen (PS:Ag) in selected disease states. 808 8

The effects of liver transplantation involving living-related donors were investigated in 20 pediatric cases in terms of protein and lipid metabolism using the extent of cholesterol esterification and the levels of total cholesterol, lecithine-cholesterol acyltransferase, apolipoprotein A-I, cholinesterase, and rapid turnover proteins as parameters. Cholesterol esterification increased from preoperative values of 39% +/- 4% to 67% +/- 1% (mean +/- SEM, n = 17) at 3 weeks after liver transplantation in successful cases but decreased from the preoperative value of 45% +/- 10% to 26% +/- 6% (n = 3) at 3 weeks in unsuccessful cases. Cholinesterase, transferrin, and prealbumin levels remained low after 3 weeks even in successful cases. Patients who had partial liver transplantations from living-related donors showed rapid recovery of cholesterol esterification. However, patients with graft livers required an extensive period before normalization of protein metabolism occurred, indicating the necessity for long-term follow-up of recipient development.
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PMID:Short-term changes in lipid and protein metabolism in liver transplants from living-related donors. 810 Oct 49


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