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)

1. Gender differences in the toxicity of diisopropylfluorophosphate (DFP; 4.0 mg/kg) and isopropyl methylphosphonofluoridate (sarin; 0.3 mg/kg) were studied in mice. 2. The animals were killed 3 hr after intraperitoneal (IP) injection of the organophosphates (OPs). 3. Although the activity of plasma butyrylcholinesterase (BChE) was two-fold higher and carboxylesterase (CaE) 1.3-fold higher in females than in males, the elevated BChE and CaE activities did not prevent inhibition of the enzyme by OPs in brain. 4. The differences in plasma BChE and CaE activities do not seem to be critical for the detoxification of OPs used in this study.
Gen Pharmacol 1997 Sep
PMID:Gender differences in activities of mouse esterase and sensitivities to DFP and sarin toxicity. 937 36

Changes in cholinesterases activities in daunorubicin cardiomyopathy and in dexrazoxane (DRZX)-treated daunorubicin cardiomyopathy were investigated in rabbits. Acetyl- and butyrylcholinesterase (AChE and BuChE) were determined using Ellman's method. In the serum, a significant decrease of BuChE was observed in the daunorubicin group (9.05 at the beginning and 7.15 microcat/l at the end of the experiment). After DRZX, no significant changes were found and a significant increase in BuChE was observed in the control group (10.26-12.38 microcat/l). AChE activity in the left and right cardiac ventricles was not significantly different between the groups while in the septum there was a significantly lower AChE activity found in the daunorubicin group only. BuChE activity was significantly decreased in the left (15.64 ncat/g) and right (19.27 ncat/g) heart ventricles, in the septum and in the liver in the daunorubicin group. A significant decrease in serum total protein and albumin was demonstrated only in the daunorubicin group. Our results support the hypothesis about the influence of daunorubicin on protein (and enzyme) synthesis in the liver and heart. A protective effect of DRZX on cholinesterases activity was observed. The changes in cholinesterase activities may thus reflect their possible role in cardiomyopathy.
Gen Physiol Biophys 1999 Dec
PMID:Cholinesterases in dexrazoxane-treated daunorubicin cardiomyopathy in rabbits. 1076 32

Isolated frog sartorii were exposed for 30 minutes to HETP-an irreversible anti-cholinesterase, and were then soaked in Ringer's at 15 degrees C. for 16 hours. At the end of the period of soaking the mean resting potential of the muscle fibers was only 29 mv. The decrease in the resting potential of the HETP-treated muscles was accompanied by a loss of potassium and a gain in sodium by the muscles. The effect of anticholinesterases on sodium extrusion was studied by incubating the muscles in a Ringer's containing half of the normal amount of sodium. The muscles respond by extruding sodium against a concentration gradient into the external medium. Sodium extrusion was blocked by prior exposure of the muscle to HETP, and reversibly blocked by exposure to physostigmine. The inhibition of sodium extrusion by physostigmine was correlated with the inhibition of the intracellular cholinesterase. Sodium extrusion was also blocked by high concentrations of 2-methyl-1,4-napthaquinone 8-sulfonic acid and by alpha-ketoglutarate, which are known to inhibit choline acetylase in vitro. But sodium extrusion was not affected by a third inhibitor of choline acetylase, phenobarbital. Sodium extrusion was unaffected by KCN and partially blocked by IAA. The IAA block was eliminated by the addition of pyruvate. It is concluded that either glycolysis or oxidative metabolism can furnish the energy needed for sodium extrusion.
J Gen Physiol 1958 May 20
PMID:The effect of enzyme inhibitors on the resting potential and on the ion distribution of the sartorius muscle of the frog. 1352 72

Frog skin cholinesterase is largely of the serum (pseudocholinesterase) type. For whole skin, the activity at 10(-1) AcChCl is 4.9 microl./mg. N/hr. Tela subcutanea isolated by dissection exhibits an activity of 65 microl./mg. N/hr. at 10(-1) AcChCl. Since about one-tenth of the nitrogen of the skin is located in the tela subcutanea, it is estimated that more than 90 per cent of the enzyme is associated with this tissue layer.
J Gen Physiol 1958 Jul 20
PMID:The characterization and localization of frog skin cholinesterase. 1356 3

An enzymatic ion exchange model for active sodium transport is described. Kinetic equations relating net flux to time, and to concentration difference across the actively transporting membrane are derived. The second of these equations is tested, using the isolated frog skin in the "short-circuit" apparatus of Ussing. Reasonable linearity, as predicted by this equation, is observed. The passive permeability coefficient for Na(+), is calculated as 5.3 x 10(-4) +/- 5.3 x 10(-4) cm./hr. If cholinesterase is assumed to be the enzyme responsible for transport, the activity required to account for the observations reported here is 17.7 x 10(-4) mmoles/cm.(2)/hr.
J Gen Physiol 1959 Jan 20
PMID:An enzymatic ion exchange model for active sodium transport. 1362 Aug 92

DFP(32), used to label erythrocytes in vitro, combines with cell constituents in two stages, the first almost immediate and involving tributyrinase inactivation, the second slower (more than 40 minutes) involving cholinesterase inactivation. Raising the DFP concentration increases the amount irreversibly bound, but increases even more the immediate post-transfusion elution, and DFP is unsuited for investigating erythrocyte viability of stored samples. In vivo tagging by intramuscular injection is satisfactory and normal survival curves are linear since the sample tagged has normal age distribution of cells in absence of random destruction. Here DFP(32) curves are easier to interpret than Cr(51) curves. In sheep, chromium elution occurs at two different rates producing a rapid initial drop followed by a slower one of about 3 per cent daily. Random destruction alters cell age distribution. New equations are derived for cases in which this is constant both with and without chromium elution; they were applied satisfactorily to dog and sheep blood. Analysis of such curves is difficult; approximate values for random destruction rates can be obtained though not potential life spans. Chromium curves can be analyzed only with the help of DFP(32) or similar curves, and yield little additional information. DFP(32) and chromium can be used simultaneously to provide controls.
J Gen Physiol 1960 Mar
PMID:The use of DFP32 as a red cell tag with and without simultaneous tagging with chromium 51 in certain animals in the presence or absence of random destruction. 1381 76

An overview of studies on the issue of dementia in Parkinson's disease shows that, over time, there has been an evolution in the perception of the magnitude of the problem and of its nature. Dementia seems today to be part of the disease. This change in the understanding of the disease can be accounted for by various methodological problems and by difficulties, on one hand, in the definition of dementia and its differentiation from other conditions, and, on the other hand, in the diagnosis of the disease itself in individual cases. Optimal therapeutic strategies are also examined, either based on cholinesterase inhibitors or antiparkinsonian drugs and symptomatic measures.
Ann Gen Psychiatry 2006 Aug 08
PMID:Phenomenology and management of cognitive and behavioral disorders in Parkinson's disease. Rise and logic of dementia in Parkinson's disease. 1689 6

A model of concentration changes across the synaptic cleft during a single quantum release is presented that can be used for description and characterization of the kinetic in postsynaptic current development under the influence of different antagonists, modulators, desensitization promoters or complex channel blockers. The model enables the calculation of the relative number of open channels as a function of time for two standard cases - when acetylcholinesterase (AChE) is either active or inhibited. One outcome of the present model is that the variable part of AChE activity is zero at the moment of acetylcholine (Ach) release and then increases. This is in contrast to common view that the activity of AChE at the initial moment of release of quanta is maximal and decreases over the time course of quantum action. However, the model explains why non-quantal ACh leakage from the nerve terminal creating a concentration of approximately 10(-8) mol.l(-1) in the cleft can escape hydrolysis by intrasynaptically located cholinesterase and reach the subsynaptic membrane. The model can also be used for theoretical considerations of time and amplitude changes during repetitive nerve-evoke quanta release.
Gen Physiol Biophys 2008 Mar
PMID:Model of concentration changes across the synaptic cleft during a single quantum release. 1843 79

The activity-pH relationship for choline esterase from horse serum, gastric mucosa of the pig, and cat brain was investigated, and an optimum was observed at pH 8.5 in each case. A micro method for the determination of choline esterase was developed capable of measuring the hydrolysis down to the order of that given by 1 x 10(-8) mol of ester.
J Gen Physiol 1938 Jan 20
PMID:STUDIES ON ENZYMATIC HISTOCHEMISTRY : XXV. A MICRO METHOD FOR THE DETERMINATION OF CHOLINE ESTERASE AND THE ACTIVITY-PH RELATIONSHIP OF THIS ENZYME. 1987 51

Extraction experiments demonstrated that choline esterase could be removed from microtome sections of tissue with as great facility by 0.9 per cent NaCl as by 30 per cent glycerol. The quantitative distribution of choline esterase through the wall of the pig stomach was studied, and it was found that the epithelial cell region possessed the greatest activity and muscle tissue the least. Pylorus was more active than fundus or cardia. The enzyme activities found were independent of the physiological state of the normal stomach at the time the animal was killed. Neither intramuscular injection of acetyl choline, eserine, nor atropine shortly before killing had significant influence upon the activity in any region of the stomach. The implications of these results were discussed.
J Gen Physiol 1938 Jan 20
PMID:STUDIES ON ENZYMATIC HISTOCHEMISTRY : XXVI. THE HISTOLOGICAL DISTRIBUTION OF CHOLINE ESTERASE IN THE GASTRIC MUCOSA NORMALLY AND AFTER ADMINISTRATION OF CERTAIN DRUGS. 1987 52


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