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:3.1.1.8 (cholinesterase)
12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cholinesterase from frozen sections of honey bee (Apis mellifera, L.) brain hydrolyzes phenylthioacetate and acetylthiocholine to give virtually identical patterns of enzyme distribution with and without the use of paraoxon. In addition, phenylthioacetate is an economical substrate for in vitro and in vivo studies of cholinesterase. Phenylthioacetate offers the advantages of being easily synthesized and lipoid soluble, and appears to penetrate membranes easily.
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PMID:Phenylthioacetate: a useful substrate for the histochemical and colorimetric detection of cholinesterase. 546 73

Cholinesterase (ChE) activity and somatostatin-like immunoreactivity (SLI) of the cerebrospinal fluid were determined for 59 patients with dementia of the Alzheimer type (AD/SDAT) and for 19 age-matched control patients with no signs of dementia. Both ChE activities and SLI concentrations of cerebrospinal fluid were reduced significantly in dementia patients compared to the controls. In the AD/SDAT patients cholinesterase and somatostatin-like immunoreactivity levels seemed to be correlated with the severity of dementia. These findings agree with observations of reduced cortical acetylcholinesterase activities and somatostatin values in dementia of the Alzheimer type.
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PMID:Reduced cholinesterase activity and somatostatin-like immunoreactivity in the cerebrospinal fluid of patients with dementia of the Alzheimer type. 614 29

Cholinesterase inhibitors are known to potentiate the effects of acetylcholine (ACh) and vagal stimulation on the myocardium. The studies presented here demonstrate that cholinesterase inhibitors (ChEI) also have activity in isolated atria in the absence of extrinsic cholinergic stimulation and that, depending on the ChEI, either indirect stimulation or direct blockade of cardiac muscarinic receptors can occur. Muscarinic agonists inhibit cyclic AMP formation in atria and the ChEIs physostigmine, neostigmine and echothiophate likewise produce a marked attenuation of isoproterenol-stimulated cyclic AMP accumulation The effect of physostigmine appears to result from muscarinic receptor activation by endogenous ACh as it is blocked by atropine. In contrast, the ChEI ambenonium does not stimulate but instead blocks muscarinic receptors coupled to cyclic AMP accumulation. Radioligand binding studies provide direct evidence that both ambenonium and demecarium are relatively potent muscarinic receptor antagonists, whereas physostigmine and other ChEI have little direct receptor activity. Physostigmine and ambenonium also have different effects on heart rate in vivo, the former potentiating and the latter apparently blocking vagal tone. The inhibition of cyclic AMP formation produced by physostigmine can be used as a measure of the concentration of endogenous ACh available at muscarinic receptor sites. Physostigmine blocks cyclic AMP formation in atria incubated in the absence of calcium or in the presence of tetrodotoxin, suggesting that endogenous ACh is spontaneously released in the absence of neuronal activity or depolarization-secretion coupling.
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PMID:Activation and blockade of cardiac muscarinic receptors by endogenous acetylcholine and cholinesterase inhibitors. 628 18

Cholinesterase activity and its various forms in the superior cervical ganglion of the rat were studied after denervation, axotomy and double section. The response of this activity to various inhibitors was also studied. The specific activity of cholinesterase activity was 323 +/- 25 nmol/mg protein/min in homogenates of normal ganglia and the total enzyme activity was 78 +/- 5 nmol/ganglion/min. Axotomy produced approximately a 40% decrease in total activity in ganglia at 3 days compared to contralateral ganglia. Activity in the contralateral ganglia was also decreased by about 30% compared to normal ganglia. Decentralization alone for 3 days did not affect the specific or total cholinesterase activity. However, decentralization followed by axotomy 3 days later resulted in a greater loss in activity compared to axotomy and a significant change in the forms of cholinesterase. After chromatography on Sepharose 6B-100 columns, 3 forms (a, c, d) of cholinesterase activity could be separated from homogenates of single ganglia. The 3 forms had estimated molecular weights of 1,934,000, 129,000 and 59,000 daltons, respectively. A fourth form (b) presented as a shoulder and had an estimated molecular weight of 404,000 daltons. Decentralization or axotomy decreased forms a and d. A reduction in the proportion of form c was also observed in the axotomized ganglion. Decentralization followed by axomoty resulted in large decreases in forms a, b and c and complete loss of form d. Assay of the separated forms in the presence of the specific inhibitor of acetylcholinesterase, BW284C-51, indicated that the majority of the enzyme recovered after chromatography is acetylcholinesterase.
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PMID:Cholinesterase activity in the rat superior cervical ganglion: effect of denervation and axotomy. 633 83

Choline, acetylcholine and betaine used as a sole carbon source, effectuate in Ps. aeruginosa an acid phosphatase activity in addition to a cholinesterase activity. Induction of both enzyme activities was repressed by succinate or glucose. Cyclic AMP failed to relieve the repression produced by these compounds. Substrates not related to choline and used as a sole source of carbon, were inefficient to produce induction of both enzymes. The in-vitro action of choline, acetylcholine and betaine on Ps. aeruginosa acid phosphatase and cholinesterase has also been studied. To perform these studies periplasmic extracts obtained by EDTA-lysozyme treatment of the cells grown on choline or betaine as sole source of carbon, were used. Acid phosphatase activity was competitively inhibited by betaine, whereas the inhibition produced by choline and acetylcholine showed competitive and noncompetitive components. Cholinesterase activity was noncompetitively inhibited by betaine. At low acetylthiocholine concentration choline was an inhibitor of cholinesterase, whereas at high substrate concentration choline raised the hydrolysis rate of acetylthiocholine. These findings allow the conclusion that acid phosphatase and cholinesterase are specifically induced by choline and its metabolites derivatives. Kinetic results led us to postulate that acid phosphatase and cholinesterase contain a similar allosteric site. This site would either be of an anionic nature or show affinity to a methyl group or display both characteristics.
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PMID:Induction of acid phosphatase and cholinesterase activities in Ps. aeruginosa and their in-vitro control by choline, acetylcholine and betaine. 640 29

The catecholaminergic innervation of three recently described dendrite bundles (midline, central and lateral) in the cervical spinal cord of the adult Long-Evans hooded rat [41] was examined using Golgi impregnation, fluorescence histochemistry for catecholamines, and cholinesterase histochemistry. The midline and lateral bundles were similar in appearance to those described by the Scheibel and Scheibel [50,51], while the central bundle, present in the region of the phrenic nucleus, has not been described previously. Analysis of Golgi-Cox impregnated horizontal sections demonstrated the presence of fine varicose fibers within all three bundles. These profiles entered the bundles at right angles, either singly or within small transverse dendritic subunits, then turned in a rostral or caudal direction, and coursed adjacent to dendrites of motoneurons in the bundles. Catecholamine histofluorescence in horizontal sections revealed abundant varicosities within all three bundles, similar in size and appearance to the varicose fibers seen in Golgi-Cox impregnated sections. Catecholamine fibers entered the dendrite bundles at right angles then turned rostrally or caudally and coursed horizontally within the bundles. Varicose fluorescent profiles formed pericellular rings around the motoneurons and linear profiles adjacent to the dendrites, sometimes outlining the entire proximal portion of primary dendrites. Catecholamine fibers entered the dendrite bundles at right angles then turned rostrally or caudally to course adjacent to the dendrites within the bundles. Cholinesterase histochemistry in alternate sections revealed staining of motoneurons and their dendrites, and confirmed the location of the catecholamine varicosities within the motoneuron dendrite bundles.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Catecholamine innervation of cervical dendrite bundles: possible phrenic nucleus innervation. 653 16

The effects of pregnancy and lactation on the toxicity and distribution of parathion and paraoxon were examined. Signs of cholinergic stimulation were more intense in pregnant mice when compared to virgin controls after administration of parathion or its active metabolite, paraoxon. Cholinesterase activity and tissue levels of parathion and paraoxon were determined in mice at 19 days of gestation or Day 19 postpartum after administration of a single dose of 5 mg/kg parathion or 0.58 mg/kg paraoxon. Plasma (pseudo) cholinesterase activity was consistently lower in treated pregnant mice. Total brain cholinesterase was also suppressed to a greater degree in pregnant mice after treatment with parathion or paraoxon when compared with virgin animals treated similarly. In addition, when equal quantities of paraoxon (32 micrograms) were administered to both pregnant and virgin animals, total brain cholinesterase was significantly less in pregnant mice. Administration of parathion to lactating mice on Day 19 postpartum did not result in any significant differences in plasma or brain cholinesterase activity when compared to that in virgin animals. Pregnant mice treated with 5 mg/kg parathion demonstrated higher concentrations of both parathion and paraoxon in blood and brain than similarly treated virgin controls which correlated with the enhanced cholinesterase inhibition. Decreased ability to detoxify paraoxon was also demonstrated by a significant reduction in serum paraoxonase activity during pregnancy.
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PMID:Influence of pregnancy on parathion toxicity and disposition. 663 86

Nineteen hundred sixteen agricultural workers who have been living in a rural area in central Japan were studied. Their age, blood pressure, Broca index, hemoglobin content, serum total cholesterol, and activity of serum cholinesterase and transaminase (GOT and GPT) were determined. The relation between the cholinesterase activity and certain physiochemical factors of the subjects was studied. Cholinesterase activity (ChE) is related to certain factors such as age, hemoglobin content (Hb), serum total cholesterol (TCh), transaminase activity (GPT), and Broca index (BI). A multiple regression equation exists between the cholinesterase activity and these factors: ln ChE = a (age) + b (Hb2) + c X ln GPT + d X ln TCh + e BI + f, where a, b, c, d, e, and f are constants. The estimated value of cholinesterase activity agrees with its measured activity. The partial correlation coefficients of the equation can be classified into the following three classes: (1) The partial correlation coefficients of total cholesterol and Broca index are nearly constant without distinction of sex and season. (2) The coefficient of hemoglobin content has a small seasonal and sexual difference. (3) The coefficients of age and GPT have a great seasonal and sexual difference. Using the equation, the most probable value of cholinesterase activity can be estimated. Therefore, the significant changes of its activity may be attributed to the toxic effects of insecticides or the abnormality of liver function.
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PMID:Multiple regression analysis of the cholinesterase activity with certain physiochemical factors. 669 17

Cholinesterase (ChE) staining was used to reveal the timing and pattern of development of afferents to the prestriate visual cortex (areas 18, 19, 20, and 21 of Brodmann) in a series of developing human and monkey fetal brains. This investigation was possible because the nucleus pulvinaris of the thalamus, the main source of subcortical projections to the prestriate cortex, displays positive reactivity after thiocholine incubation during the last three quarters of gestation, while neighboring thalamic nuclei that project to the adjacent neocortical areas are unstained. Staining of the pulvinar and its prestriate projections passes through six broad stages. Stage I begins in both species at the end of the first third of gestation. Positively stained fibers originate from the pulvinar and enter but do not extend beyond the hemispheric stalk. During stage II, pulvinar axons gradually invade the intermediate zone of the occipital lobe, and in stage III they reach the level of the subplate zone. In stage IV, which occurs around mid-gestation in both species, cholinesterase-positive fibers accumulate within the subplate zone subjacent to the developing prestriate cortex. During stage V, ChE-positive fibers penetrate the prospective prestriate cortex but do not yet form the alternating columnar pattern characteristic of pulvinar input to this area in the adults. Rather, ChE activity is concentrated in two continuous bands situated within prospective layers III-IV and VI; also a narrow band is visible in upper layer I. In stage V a clear histochemical border forms between prestriate and striate areas with ChE activity in prospective area 17 limited mostly to the superficial strata of layers I and II. This histochemical differentiation precedes the emergence of cytoarchitectonic landmarks. During stage VI, which begins in the last fifth of gestation in both species, the pulvinar become progressively less stainable and its projections can no longer be traced by ChE histochemistry.
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PMID:Development of prestriate visual projections in the monkey and human fetal cerebrum revealed by transient cholinesterase staining. 669 40

Recognition of exposure to imidan was assessed in goats by dialkyl phosphate concentrations, blood cholinesterase (ChE) determinations, and blood imidan concentrations. Groups of three goats received 5.0 mg imidan/kg/day (low dose) or 10 mg imidan/kg/day (high dose) for 7 days orally. One goat received no imidan and one goat received an acute single dose (200 mg/kg). The urine of all treated goats was examined for the excretory dialkyl phosphates, O,O-dimethyl phosphorodithioate (DMDTP) and O,O-dimethyl phosphorothionate (DMTP). The overall mean DMDTP urinary concentration was 19.1 ppm (10-mg/kg treatment group) and 7.2 ppm (5-mg/kg treatment group). These metabolites rapidly disappeared following removal of the treatment except in those goats clinically affected. Milk contained no identifiable concentrations of dialkyl phosphates. Cholinesterase depression was observed in all imidan-treated goats, and a dose effect was observed. No imidan was detected in whole blood of either the 5- or 10-mg/kg treatment groups. Low blood concentrations (ppb) of imidan were measured in the acute single-dose exposed goat. Both urinary DMDTP and blood ChE provided recognition of imidan exposure. DMDTP, however, was immediately present in urine after exposure and provided stronger support for organophosphate exposure than did blood ChE.
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PMID:Comparison of measurement of dialkyl phosphates in milk/urine and blood cholinesterase and insecticide concentrations in goats exposed to the organophosphate insecticide, imidan. 669 74


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