Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 20-year-old male who attempted suicide by injecting subcutaneously 10 ml of Sistemin 40 (40% dimethoate) was admitted 16 h later. General weakness, muscular fibrillations and a marked inhibition of red blood cell and serum cholinesterases were the prominent signs of intoxication. The antidotal treatment of intermittent boluses of atropine, oxime HI-6 and diazepam was combined with symptomatic therapy. Cholinesterase activity decreased within the next 3 d. In contrast to the marked general improvement of the patient, the return of cholinesterase activities was very slow. The patient was discharged 24 d after the poisoning with no notable consequences which could be ascribed to the intoxication.
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PMID:A case of unusual suicidal poisoning by the organophosphorus insecticide dimethoate. 232 50

A spectrophotometric assay was established to determine circulating levels of cholinesterase (ChE) in the whole blood of rats. A commercially available ChE reagent set was obtained and the suggested procedure modified to quantify and correct for the activity resulting from nonenzymatic hydrolysis of the substrate. The stability of ChE as well as the effect of sampling site, exercise, and carbamate administration were evaluated. The ChE activity of blood drawn from a jugular cannula (central sample) was less than that drawn from a lateral tail vein (peripheral sample), but percent change in activity between sampling times was not different between the two sites. Cholinesterase in carbamate-inhibited blood was not stable and had to be assayed soon after sampling. Therefore, if the assay is performed soon after sampling, rat whole blood ChE activity may be determined spectrophotometrically, and the blood may be sampled either peripherally or centrally.
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PMID:Spectrophotometric determination of circulating cholinesterases in rats. 233 76

Rat serum lipoprotein phospholipids and serum cholinesterase activity in control and thioacetamide-treated rats (50 mg/kg/day for 30 days) were studied. Analyses were done after 1, 3, 8 and 30 intraperitoneal doses of thioacetamide or 0.15 mol/l NaCl. Cholinesterase activity significantly increased with thioacetamide treatment. Only two phospholipids: LDL-phosphatidylcholine and HDL-lysophosphatidylcholine appeared associated with cholinesterase activity. LDL-phosphatidylcholine increased through the action of hepatotoxic thioacetamide while HDL-lysophosphatidylcholine significantly decreased. Because of the high statistically significant association between changes in these lipoprotein phospholipids and in cholinesterase in this model of hepatic injury, we conclude that cholinesterase could be involved in the regulation of these phospholipid levels.
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PMID:Association between rat serum cholinesterase and some phospholipid components of lipoproteins in thioacetamide-induced hepatic injury. 239 38

Previous anatomical descriptions of the diaphragm have contained several contradictory findings. To validate and extend the previous work, diaphragmatic architecture, histochemistry, and end-plate distribution were examined by use of a combination of anatomical methods, including fiber microdissections, cholinesterase staining, and enzyme histochemistry. Microdissections showed that muscle-fiber fascicles throughout the diaphragm contain both long fibers that run from origin to insertion and shorter fibers with intrafascicular terminations. Fibers with intrafascicular terminations were particularly common in the costal diaphragm, where they accounted for the majority of sampled fibers. The heterogeneity of fiber length was reflected in the pattern of end-plate banding. Cholinesterase studies showed that fiber fascicles in cat and kitten diaphragms were crossed by two to four end-plate bands distributed in discontinuous arrays across the width of the muscle. A similar pattern of multiple banding was also demonstrated in the adult and neonatal dog. However, rat and rabbit diaphragms had only a single, continuous end-plate band. Histochemical studies of fiber types in different parts of the feline diaphragm showed that costal, crural, and sternal subregions had similar overall proportions of fiber types. However, type SO (slow oxidative) fibers were distributed more densely on the thoracic than the abdominal surface of costal and crural, but not sternal subregions. Type SO fibers were also concentrated in fiber fascicles bordering the esophageal hiatus.
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PMID:Muscle-fiber architecture, innervation, and histochemistry in the diaphragm of the cat. 247 63

1--The innervation of the liver and gallbladder of Rana ridibunda has been studied by the following methods: (a) demonstration of cholinesterase activity; (b) FIF method for catecholamines; (c) immunohistochemistry for VIP and (d) electron microscopy. 2--The hepatocytes are arranged in regular rows of hepatic cords, very little connective tissue is distributed in the parenchyma, the innervation being restricted to the big branches of blood vessels. 3--Well defined cholinergic and adrenergic plexuses surround the hepatic arteries, portal veins and biliary ducts. The VIPergic innervation is scarce in the liver but a richly branched plexus spreads in the wall of the gallbladder. 4--Cholinesterase-positive cells are widely distributed accompanying the nerve trunks of the gallbladder. The innervation distribution is prominent in the portion of the gallbladder next to the hepatic hilus. 5--A population of melanin-storing cells besides free melanin granules are present in the liver parenchyma and are prominent in the gallbladder where the melanocytes are disposed in close contact with blood vessels and nerve structures. We have observed that the number of these visceral melanocytes considerably increases in winter, particularly in the liver.
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PMID:The autonomic innervation of the liver and gallbladder of Rana ridibunda. 252 Apr 74

Using radioligand assay it was demonstrated that chlorophos intoxication produced inhibiting effect on the kinetics of membrane binding of 3H3-quinuclidinylbenzilate and 14C-cyclosil in the brain. Cholinesterase reactivator dipyroxime was shown to induce normalization of the cyclosyl specific binding kinetics. It seems to be justified to propose that cooperative action of cholinolytic agents and cholinesterase reactivator at the level of m-cholinoreceptors in the course of intoxication may be one of the mechanisms of the potentiation of therapeutic effects of these drugs.
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PMID:[Modification of selective adsorption of muscarinic antagonists in cerebral membranes during chlorophos poisoning]. 259 61

The commercially available kits (Test-Combination, Cholinesterase, Boehringer, Mannheim and Test-reagent, Cholinesterase EC 3.1.1.8, Pliva, Zagreb) and reagents prepared in own laboratory for measuring cholinesterase activity (Ellman method) were tested with respect to their stability and the reproducibility of the activity measurements. The reagents of the three sources were shown to be interchangeable and equally stable over a few weeks. The coefficient of variation for within-run measurements by the Ellman method was 2-3% and that for between-run measurements 6%. The stability of the few enzyme standards (Precinorm E, Precinorm U, NBS-serum and native human serum) for the quality control of the measurements was also tested: the most stable was native human serum.
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PMID:[Measurement of serum cholinesterase activity: comparison of commercial and laboratory test reagents, enzyme standards and statistical processing of the results]. 263 23

Cholinesterase activities and characteristics of muscarinic and dopamine receptors from 9 week old male Sprague-Dawley (SD), Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were studied. Plasma cholinesterase activity in WKY was significantly lower (50%) than activity in the other strains. In studies of muscarinic receptors, the number of [3H]QNB binding sites in striata from SD rats was lower (18%) than those from WKY and SHR. However, muscarinic receptor properties (Kd and Bmax) were the same in hypothalami. Studies of dopamine receptors revealed that the densities of both D-1 and D-2 receptors in both striata and hypothalami were significantly higher in SHR than in other strains. However, there were no differences in the affinity constant (Kd). The higher densities in hypothalami from SHR were mainly due to the high population of D-1 and D-2 receptors in the posterior hypothalamus. In the anterior hypothalamus, there was no difference in the population of D-2 receptors. These results provide a substantive basis, i.e. demonstration of alterations in drug metabolizing enzymes and receptor populations, on which to build an understanding of the genetic predisposition to the actions of xenobiotic agents.
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PMID:Comparative studies of muscarinic and dopamine receptors in three strains of rat. 267 98

Time and feeding influences on cholesterol, triglyceride, glucose and insulin levels, and serum cholinesterase activity were assessed in a genetically-hyperlipidemic hyperphagic obese rat model, and compared with its lean litter-mate. Following a 28-day acclimation to a 12-hr light/dark cycle, blood samples were obtained every 2 hr from rats via tail bleed for a 24-hr period. Synchronization with other animal studies was established by endogenous serum cortisol levels [acrophase 18-20 hr after light onset (HALO) in both groups]. Triglycerides cholesterol, insulin and glucose levels were significantly elevated in obese versus lean rats. Obese rats were observed to feed throughout the 24-hr cycle, whereas lean litter-mates ate only during the dark cycle. No circadian rhythmicity was found in glucose levels with either rat group. Insulin levels were not correlated. Although triglyceride levels peaks at 13 HALO in lean rats, no pattern was observed in obese rats. Cholesterol levels were unchanged with time in either group. Cholinesterase activity followed a circadian rhythm in the lean, but not obese, rats with an acrophase estimated at 8 HALO. In contrast to previous reports, enzyme activity was not correlated with triglyceride levels in either rat group. Circadian similarities in insulin levels between rat groups suggest changes in insulin metabolism and/or secretion which are likely to be independent of feeding or activity. Conversely, triglyceride levels remained elevated throughout the 24-hr period in obese rats, whereas significant increases were observed in lean rats during the dark active cycle. These data suggest that triglyceride levels, and not insulin and cholesterol levels, are most likely dependent on feeding patterns.
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PMID:Circadian assessment of lipids in the hyperphagic obese rat compared with lean litter-mates. 268 Jan 23

The distribution, metabolism, and pharmacokinetics of physostigmine (Phy) and the time course of butyrylcholinesterase (BuChE) in plasma and cholinesterase (ChE) activity in brain and muscle and their relationship to Phy concentration were described after oral administration of 3H-Phy (650 micrograms kg-1) to rats. Physostigmine concentration vs time data was analyzed by nonlinear computer fitting program using one-compartment model. The absorption rate constant (ka) and elimination rate constant (ke) were found to be 0.1 +/- 0.07 min-1 and 0.036 +/- 0.024 min-1, respectively. Cpmax and tmax were 3.3 ng ml-1 and 16 min. The clearance (C1) was found to be 80.9 ml min-1kg-1. Half-life of Phy in brain, muscle, and liver were 33.4 min, 22.5, and 28 min, respectively. The bioavailability (F) was calculated to be 0.02 and the extraction ratio was found to be 0.98 indicating the 'first pass' effect. Butyrylcholinesterase activity in plasma was 76 per cent at 15 min and this activity did not change significantly up to 120 min. However, Phy concentration in plasma was very low; 2.89 ng ml-1 at 15 min and declined to 0.71 ng ml-1 at 90 min. Physostigmine concentration in brain peaked at 22 min to 2.85 +/- 1.09 ng g-1 and declined to 0.33 +/- 0.11 ng g-1 at 60 min. Cholinesterase activity in brain was 96 per cent, 82 per cent and 89 per cent at 10, 45, and 120 min, respectively. Physostigmine concentration in muscle was very low and the ChE activity in the muscle was 66.4 per cent of control at 45 min. The time course of Phy metabolism indicated that at 5 min most of the RA in the tissues was due to metabolites accounting for 94.6 per cent in plasma, 90 per cent in liver, 79.8 per cent in brain and 86.3 per cent in muscle. M1 appeared to be the major metabolite followed by eseroline. The results showed extremely low concentrations of Phy (200 times less in plasma and 350 times less in brain) after oral administration compared to our previous studies with the same dose after i.m. administration.
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PMID:Pharmacokinetics and pharmacodynamics of physostigmine in the rat after oral administration. 270 18


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