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PubMed1987

Complete amino acid sequence of human serum cholinesterase.

The complete amino acid sequence of human serum cholinesterase (choline esterase II (unspecific), EC 3.1.1.8) was determined by Edman degradation of purified peptides. The protein contains 574 amino acids per subunit and nine carbohydrate chains attached to 9 asparagines. The four subunits of cholinesterase appear to be identical. The active site serine is the 198th residue from the amino terminus. The sequence of human serum cholinesterase is 53.8% identical with the sequence of acetylcholinesterase from Torpedo californica and 28% identical with the carboxyl-terminal portion of bovine thyroglobulin.

Amino Acid Sequence↗

PubMed1987

Cholinesterase assay automated in the Cobas-Bio centrifugal analyzer.

We describe a method for measuring plasma cholinesterase (EC 3.1.1.8) and dibucaine and fluoride numbers by using the Cobas-Bio. Benzoyl choline chloride is used as substrate. Reaction conditions are the same as in the corresponding manual method. The reaction is stopped with physostigmine. Choline oxidase (EC 1.1.3.17) is coupled with 4-aminoantipyrene. In the presence of peroxidase (EC 1.11.1.7), the 2-hydroxy-3,5-dichlorobenzenesulfonate indicator reaction gives a red product, measured at 505 nm. The analyzer is used in the "Multi Run" mode, with plasma cholinesterase and dibucaine and fluoride inhibition concurrently measured for eight samples. Coefficients of correlation between the manual and present method for plasma cholinesterase and dibucaine and fluoride numbers in 40 patients of various phenotypes were 0.843, 0.923, and 0.717, respectively. The inter-batch CV for each of the three assays was 2% to 3%.

Autoanalysis↗

PubMed1985

Changes in end-plate cholinesterase and axons during muscle degeneration and regeneration.

Injection of bupivacaine into the rat anterior tibial muscle produced rapid necrosis with disintegration of muscle fibres and phagocytic infiltration within two days. Regenerating myotubes appeared four days after injection, and muscle structure was restored seven days after injection. One day after injection, axons and end-plate cholinesterase appeared normal in spite of the underlying muscle fibre necrosis. Intensity of cholinesterase staining was gradually reduced through the second and third day but axons remained intact. On the fourth day, newly formed end-plates delineated by cholinesterase stain were seen on myotubes. Some were innervated by thin regenerating axons. Axonal outgrowth appeared to compensate for occasional neuronal degeneration and for the greater number of end-plates on myotubes. In some areas, not all end-plates were innervated by the fourth day but were by the fifth day. On the sixth and seventh day after myotube maturation, a process of degeneration of superfluous end-plates and axons occurred, reducing their number to the number of muscle fibres. Fourteen and 28 days after injection, the innervation pattern was normal except for a slight increase in terminal innervation band width. These results indicate that injection of bupivacaine does not directly affect intramuscular nerves and that the changes observed in this experimental model are the consequence of muscle fibre degeneration and regeneration.

Animals↗

PubMed1985

Effect of sodium fluoride on cholinesterase activity in postmortem blood.

Thirty-two postmortem blood specimens, with and without sodium fluoride as preservative, were analyzed for cholinesterase activity by the Michel method. The fluoridated specimens, which contained from 0.7 to 31 mg/mL (average 6.3) of sodium fluoride, were found to exhibit cholinesterase activities that were 5 to 59% (average 25%) lower than the duplicate unfluoridated specimens. We concluded that, while this decrease is quite significant, a fluoridated postmortem blood specimen may be used for the measurement of cholinesterase activity when a non-fluoridated specimen is unavailable.

Acetylcholinesterase↗

PubMedDate not supplied

[Age and the effect of proserine on the contractile response of the rectum and inhibition of its cholinesterase in rats].

The motor reaction of the rectum strips in rats of 4 age groups and inhibition of its cholinesterase with proserine were studied. To low proserine concentrations (1.10(-8)-1.10(-6) M) the intestine of 1-week old rattlings was found to react only by relaxation, contractions appearing only with a concentration of 1.10(-5) M. The maximal contractile reaction of the intestine to proserine was found to occur in 4-week old rattlings. The cholinesterase activity in the rectum of 1-week old rattlings is lower, and in the 4-week old ones higher than in adult animals. The inhibition of cholinesterase occurs in all the age groups from a minimal tested proserine concentration (1.10(10) M), gaining in strength parallel with increasing concentration. The maximum inhibition of the enzyme was found to occur in the 4-week old rattlings.

Age Factors↗

PubMed1969

Appraisal of collection techniques and storage temperatures on turkey plasma cholinesterase levels and blood glutathione concentrations.

The effects of different blood collection procedures, various storage temperatures and durations of storage on the levels of plasma cholinesterase and whole blood glutathione in turkeys were investigated. Collection of blood through vacutainers yielded satisfactory results. Whereas the plasma cholinesterase activity remained unchanged even after three weeks of storage at -17.8 degrees C., blood glutathione concentration was unaffected only when the samples were stored at -28.9 degrees C for the three weeks. The range of mean activity was from 4.64 to 4.71 DeltapH/hour x 10 for cholinesterase and from 44.85 to 47.91 mgm/100 ml for glutathione.

Animals↗

PubMedDate not supplied

[Histochemical study of cerebral cortex cholinesterases during early mammalian ontogeny].

Histochemical studies have been made on changes in true cholinesterase and pseudocholinesterase in mammalian ontogenesis. It was found that at early ontogenetic stages the enzymes are located mainly in deep layers. In rabbits, early accumulation of the true cholinesterase takes place; evident maximum of the reaction was found directly over the fibres of the cortical white matter during the last days of foetal development and in newborn animals. Accumulation of pseudocholinesterase in myelinating fibers begins at the 7-10th day. In the cortex of human foetuses, evident heterochronous accumulation of cholinesterase was noted, since the enzyme was concentrated mainly in the occipital and frontal parts of the isocortex.

Acetylcholinesterase↗

PubMed1971

Distribution and determination of cholinesterases in mammals.

This paper reviews the distribution of cholinesterases in the central nervous system, the ganglia, the striated muscle, and the blood of mammals, and discusses the correlation between the histochemical localization and the function of neuronal cholinesterase.Different methods for the determination of cholinesterase levels are reviewed, with particular reference to their practical value for field work. The Warburg method and the Tintometer and Acholest colorimetric methods are compared on the basis of cholinesterase levels determined in normal persons and in those suffering from parathion intoxication.

Acetylcholinesterase↗

PubMedDate not supplied

Serum cholinesterase levels in patients with cancer.

Serum cholinesterase levels were determined in 180 patients with carcinoma and in 146 normal subjects. Serum cholinesterase activity was significantly lower in patients suffering from cancer than in normal controls, though still within the normal range. The degree of depression of serum cholinesterase activity was influenced by the extent to which the malignancy had spread and by the site of the primary lesion.

Cholinesterases↗

PubMed1984

[Polymorphism of human blood serum cholinesterase in populations of Evenks and Yakuts in Krasnoyarsk Territory].

Polymorphism for E2 locus of human serum cholinesterase was studied in populations of evenks and yakuts of Krasnoyarsky region by the method of starch gel electrophoresis. Thee frequencies of C5+ phenotype correspond to C5+ frequencies in other mongoloid populations of Siberia. The activity of cholinesterase was determined by semiquantitative technique. Three individuals with a sharply decreased cholinesterase activity have been revealed.

Cholinesterases↗

PubMed1983

Effect of propoxur-impregnated pesticide tape on mouse cholinesterase levels.

Mice housed in polycarbonate cages, either with or without fiberglass filter bonnets, were exposed to propoxur-impregnated tape for 2 hours, 24 hours, or 7 days. Both erythrocyte and serum cholinesterase levels were determined at each time point. Body weights were also measured. There was no change in body weight or serum cholinesterase level. Erythrocyte cholinesterase level showed significant decrease, related to increasing length of exposure.

Animals↗

PubMed1983

[Cholinesterase (EC 3.1.1.8) with butyrylthiocholine-iodide as substrate: references depending on age and sex with special reference to hormonal effects and pregnancy].

Referance values are reported for the assay of cholinesterase (substratae: butyrylthiocholine iodide) in serum at 25 degrees C. There was no evidence of any age-dependency or sex-specific distinction in children (1 to 15 years, N = 309), nor were there any age-dependent changes observed in males (16 to 94 years, N = 718). Compared with the reference range for children, there was no detectable difference in the location and distribution of catalytic cholinesterase concentrations. In females (16 to 99 years, N = 861), an age-dependent difference in cholinesterase values became apparent: Regardless of pregnancy or use of hormonal contraceptives, the catalytic concentrations were found to be lower in younger females (16 to 39 years) than in older ones (greater than or equal to 40 years); the reference values in the older age group (40 to 99 years) did not differ from those of males and children. Therefore the following reference values are proposed (in each case 2.5 to 97.5 percentile: Children, males and females above 40 Years: 3.5 to 8.5 kU/l, Females (16-39 years, nonpregnant, not taking hormonal contraceptives): 2.8 to 7.4 kU/l, Females (18-41 years, pregnant or taking hormonal contraceptives): 2.4 to 6.0 kU/l.

Adolescent↗

PubMed1981

[Interaction of frog brain cholinesterase with some reversible ammonium inhibitors].

The effects of some ammonium compounds diiodomethylate acetate (I), propionate (II), butyrate (III), valeriate (IV) N-hydroxyethylanabasine, tetramethylammonium, tetraethylammonium and acetylcholine amide analog derivatives (V-VIII) on acetylthiocholine hydrolysis by cholinesterase from frog brain, acetylcholinesterase from human erythrocytes and butyryl cholinesterase from horse blood serum were studied. Cholinesterase from frog brain possesses a lower sensitivity to the inhibitors than does the mammalian enzyme. Significant conformational changes of the inhibitor molecule, i. e. transition from trans-conformation (V) to the fixed gosh-conformation (VII), have no effect on the anticholinesterase activity of these compounds. A method for evaluation of effectivity of different types of the reversible inhibitors is proposed.

Animals↗

PubMed1982

Effect of dietary trans fatty acids on cholinesterase and monoamine oxidase activities in different organs of rats.

The effect of trans fatty acids and essential fatty acid deficiency upon the activities of cholinesterase and monoamine oxidase in livers, hearts, brains and lungs of rats was studied. This study was performed using three groups of male albino rats. Two out of these three groups were fed essential fatty acid low diets containing 10% hydrogenated coconut oil (HCNO) or margarine stock (MS, partially hydrogenated soybean oil) while the third group was fed an adequate supply of essential fatty acids through a diet containing 10% corn oil (CO). In the group of rats fed HCNO the activities of cholinesterase and monoamine oxidase in their livers, hearts, brains and lungs were not significantly different from those of the control group fed CO. In the group of rats fed MS, the activity of cholinesterase was significantly decreased in the livers, hearts and brains, but not affected in the lungs, while the activity of monoamine oxidase was significantly decreased in the livers and hearts but not affected in the brains and lungs as compared to the control group fed CO. The levels of serum total lipids, total cholesterol and triglycerides were elevated in both groups of rats fed HCNO or MS than in the group fed CO, but this elevation was more highly significant in the group fed MS than in the group fed HCNO.

Animals↗

PubMed1982

Modifications of Michel's electrometric method for rapid measurement of blood cholinesterase activity in animals: a minireview.

Various modifications and improvements of the electrometric method of Michel for measurement of blood cholinesterase activity in animals are reviewed. Reported normal values of blood cholinesterases activities for different animal species are tabulated. A modified electrometric method is described and recommended for the measurement of erythrocyte and plasma cholinesterase activities of sheep.

Animals↗

PubMed1981

Automated discrete kinetic method for erythrocyte acetylcholinesterase and plasma cholinesterase.

We describe an automated kinetic method for erythrocyte acetylcholinesterase (EC 3.1.1.7) and plasma cholinesterase (EC 3.1.1.8) based on Ellman's colorimetric method. Quinidine sulfate is used as an inhibitor of plasma cholinesterase during the measurement of erythrocyte acetylcholinesterase activity, obviating the need for washing the erythrocytes before lysis. Results by this method are compared with those obtained by the electrometric delta pH method of Michel. To emphasize the need for measuring both erythrocyte acetylcholinesterase and plasma cholinesterase activity in workers exposed to organophosphate pesticides, we present a study of serial activities of both enzymes in a person accidentally exposed to demeton-S-methyl.

Acetylcholinesterase↗

PubMed1995

Effects of cholinesterase inhibitors and clonidine coadministration on rat cortex neurotransmitters in vivo.

In previous investigations, we have demonstrated that cholinesterase inhibitors such as physostigmine (PHY) and heptylphysostigmine (HEP) elicit a significant and simultaneous increase in acetylcholine (ACh) and norepinephrine (NE) levels in the rat cortex. This effect is enhanced by idazoxan, a selective alpha-2 antagonist. These data suggest that a combination of cholinergic and adrenergic drug may improve the pharmacological effect of the cholinesterase inhibitor on cortical neurotransmitters such as ACh-NE. In order to obtain additional information on cortical cortical neurotransmitter interaction, we tested, in the cerebral cortex of the rat, the effect of PHY and HEP in animals pretreated with clonidine (CLO), a selective alpha-2 agonist, on ACh, NE, dopamine and 5-hydroxytryptamine) extracellular levels. We detected no effect of systemic or intracortical CLO administration of ACh levels, but NE, dopamine and 5-hydroxytryptamine levels were all decreased. Systemic coadministration of CLO and PHY significantly elevated ACh levels and decreased NE, dopamine and 5-hydroxytryptamine levels. Systemic coadministration of CLO and HEP produced a significant elevation in ACh levels. Comparison between the two treatment combinations shows that, although CLO coadministration reduces the effect of PHY on ACh levels, HEP administered to animals pretreated with CLO produces a stronger effect than HEP alone. A possible explanation for this difference is the variation in duration of the two drugs on ACh elevation and muscarinic receptor desensitization. As a result of the alpha-2 agonist cholinesterase inhibitor coadministration, our data suggest that such a combination does not represent an advantage as a therapeutical alternative for treatment of cognitive impairment in Alzheimer disease patients.

Acetylcholine↗

PubMedDate not supplied

A field method for the determination of whole blood cholinesterase.

Blood cholinesterase activity is an efficient indicator of exposure to organophosphate insecticides. Field methods, in spite of lacking sensitivity, are important when practical determinations and immediate results are necessary One of the mostly used field methods to assess blood cholinesterase activity is the Lovibond Cholinesterase Field Kit. This paper proposes to substitute the comparator disk of the Lovibond Field Kit with a set of standard solutions that exhibit similar colours. Dilutions of Bromothymol blue, whole blood and acetic acid in different concentrations were used to construct a set of coloured solutions which correspond to different degrees of ChE inhibition. The comparison of acetylcholinesterase activity measured with the two methods showed good agreement and satisfactory reproducibility of results. The use of a standard colored solution kit seems more suitable and manageable for field studies than the Lovibond comparator disk.

Acetylcholinesterase↗