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)

The fluoride variant of human butyrylcholinesterase owes its name to the observation that it is resistant to inhibition by 0.050 mM sodium fluoride in the in vitro assay. Individuals who are heterozygous for the fluoride and atypical alleles experience about 30 min of apnea, rather than the usual 3-5 min, after receiving succinyldicholine. Earlier we reported that the atypical variant has a nucleotide substitution which changes Asp 70 to Gly. In the present work we have identified two different point mutations associated with the fluoride-resistant phenotype. Fluoride-1 has a nucleotide substitution which changes Thr 243 to Met (ACG to ATG). Fluoride-2 has a substitution which changes Gly 390 to Val (GGT to GTT). These results were obtained by DNA sequence analysis of the butyrylcholinesterase gene after amplification by PCR. The subjects for these analyses were 4 patients and 21 family members.
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PMID:Identification of two different point mutations associated with the fluoride-resistant phenotype for human butyrylcholinesterase. 141 24

Several cholinergic processes were demonstrated and partially characterized in rabbit kidney cortical minces: choline uptake, acetylcholine synthesis and calcium-dependent release. Minces took up labelled choline, acetylated it, and stored it in a pool that was not readily accessible to physostigmine-sensitive cholinesterase activity. [3H]Acetylcholine synthesis but not [3H]choline uptake was inhibited by the removal of sodium ions or incubation at 0 degrees C. The release of newly synthesized [3H]acetylcholine was increased by 300 mOsmol urea in a calcium-dependent manner, but not by potassium depolarization (300 mOsmol), vasopressin (10 microM), or bradykinin (10 microM). These results suggest that acetylcholine may be synthesized by non-neuronal rabbit kidney cortical cells and that this transmitter may be released in response to physiological levels of urea.
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PMID:Synthesis and release of acetylcholine in the rabbit kidney cortex. 143 79

We measured the blood levels of cocaine and its three major metabolites, benzoylecgonine, ecgonine methyl ester, and norcocaine, in three groups of male pigs weighing about 26 kg (25.75 +/- 0.25 kg) to determine the effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine metabolism. In addition, systemic elimination half-life, volume of distribution, and clearance of cocaine were calculated for the three groups. Group 1 pigs (n = 4) were pretreated with normal saline solution, group 2 pigs (n = 4) were pretreated with tetraisopropyl pyrophosphoramide, a specific plasma cholinesterase inhibitor, and group 3 pigs (n = 4) were pretreated with cimetidine, a hepatic microsomal enzyme inhibitor, all administered intramuscularly. Pigs were anesthetized with intravenous sodium thiopental; a carotid arterial cannula and an external jugular catheter were then inserted for the administration of cocaine and for blood sampling. Forty-five minutes later, when pigs were again completely awake, cocaine 3 mg/kg was given intravenously. Arterial blood samples were collected for the analysis of cocaine and cocaine metabolite levels just before and at 5, 10, 15, 30, 45, 60, 120, 180, and 1440 minutes after the administration of cocaine. Cocaine and cocaine metabolite blood levels were analyzed with high-pressure liquid chromatography methods and plasma cholinesterase activity was measured with a colorimetric method. The blood levels of cocaine and cocaine metabolites were significantly different among the three groups (p less than 0.05, analysis of variance). Statistically significant differences in half-life, volume of distribution and clearance were also seen among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effects of inhibition of plasma cholinesterase and hepatic microsomal enzyme activity on cocaine, benzoylecgonine, ecgonine methyl ester, and norcocaine blood levels in pigs. 150 Aug 30

A 29-year-old patient suffering from stenosis of the rectum and a periproctal fistula due to a severe form of Crohn's disease was completely fed by the parenteral route for 15 months, incl. 13 months at home, via a totally implanted cannula system Implantofix, Braun Co.. The patient felt throughout the period of parenteral nutrition very well, he worked and the secretion from the fistula stopped after four weeks. After 15 months of complete parenteral nutrition and elimination of oral food intake a marked improvement of the local finding in the rectum was observed. All laboratory findings (haemogram, liver tests, urea, creatinine, transferrin, albumin, cholinesterase and pre-albumin, serum levels of sodium, potassium, chlorides, calcium and phosphates) were throughout the observation period within a normal range. The body weight of the patient increased during the 15 months by 1 kg. The described case is the first one where domiciliary parenteral nutrition was used in Czechoslovakia under ambulatory conditions.
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PMID:[Long-term home parenteral nutrition using a totally implanted cannulation system]. 150 94

Acetylcholinesterases (EC 3.1.1.7, AChE) have varying amounts of carbohydrates attached to the core protein. Sequence analysis of the known primary structures gives evidence for several asparagine-linked carbohydrates. From the differences in molecular mass determined on sodium dodecyl sulfate-polyacrylamide gel before and after deglycosylation with N-glycosidase F (EC 3.2.2.18), it is seen that dimeric AChE from red cell membranes is more heavily glycosylated than the tetrameric brain enzyme. Furthermore, dimeric and tetrameric forms of bovine AChE are more heavily glycosylated than the corresponding human enzymes. Monoclonal antibodies 2E6, 1H11, and 2G8 raised against detergent-soluble AChE from electric organs of Torpedo nacline timilei as well as Elec-39 raised against AChE from Electrophorus electricus cross-reacted with AChE from bovine and human brain but not with AChE from erythrocytes. Treatment of the enzyme with N-glycosidase F abolished binding of monoclonal antibodies, suggesting that the epitope, or part of it, consists of N-linked carbohydrates. Analysis of N-acetylglucosamine sugars revealed the presence of N-acetylglucosamine in all forms of cholinesterases investigated, giving evidence for N-linked glycosylation. On the other hand, N-acetylgalactosamine was not found in AChE from human and bovine brain or in butyrylcholinesterase (EC 3.1.1.8) from human serum, indicating that these forms of cholinesterase did not contain O-linked carbohydrates. Despite the notion that within one species, the different forms of AChE arise from one gene by different splicing, our present results show that dimeric erythrocyte and tetrameric brain AChE must undergo different postsynthetic modifications leading to differences in their glycosylation patterns.
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PMID:Different glycosylation in acetylcholinesterases from mammalian brain and erythrocytes. 154 61

Applying a new four-step isolation procedure, we have purified butyrylcholinesterase (BChE) from chicken serum to homogeneity with more than 250 U/mg specific activity. The serum enzyme was used for producing monoclonal antibodies. These BChE-specific also recognize BChE from brain, and thus enabled us to isolate the enzymes from embryonic and adult brain that occur only in minute amounts. More than 50% of the brain BChE is membrane-bound. The catalytic and inhibition properties of brain BChE are similar to those of serum BChE. However on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the serum enzyme is represented by a double-band of 79/82 kDa, whereas the brain enzyme has a size of 74 kDa. Limited digestion of the serum and brain preparations by V8-protease leads to similar peptide patterns. Enzymatic deglycosylation shows that their core proteins consist of 59-kDa subunits and that the different molecular weights are due to different glycosylation patterns. The differently sized glycosylation parts of brain and serum BChE may indicate that they subserve different functions. Furthermore, the membrane-bound brain BChE can be solubilized by Pronase or protease K, but not by phosphatidylinositol-specific phospholipase C.
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PMID:Butyrylcholinesterase from chicken brain is smaller than that from serum: its purification, glycosylation, and membrane association. 157 4

We studied the effect of inhibition of pseudocholinesterase by a specific pseudocholinesterase inhibitor, tetraisopropyl pyrophosphoramide (ISO-OMPA) on the cardiorespiratory toxicity of intravenously injected cocaine in rats. Group 1 rats received ISO-OMPA subcutaneously, whereas group 2 rats received saline placebo subcutaneously. Thirty minutes later, rats were anesthetized with 40 mg/kg of sodium pentobarbital intraperitoneally and were then given 10 mg/kg (least toxic dose) cocaine intravenously. Thirty minutes after the first injection of cocaine, about half of the rats that survived from each group were given 12 mg/kg cocaine (low toxic dose) intravenously, and the other half was given 13.5 mg/kg cocaine (high toxic dose) intravenously. Five minutes after each injection, rats were classified as either survivors or fatalities. In group 1 (ISO-OMPA treated), five of 29 (17%) rats that received 10 mg/kg cocaine, two of 11 (19%) that received 12 mg/kg cocaine, and three of 13 (24%) that received 13.5 mg/kg cocaine died of cardiorespiratory toxicity. In group 2 (saline treated), two of 29 (7%) that received 10 mg/kg cocaine, six of 12 (50%) that received 12 mg/kg cocaine, and 10 of 15 (67%) that received 13.5 mg/kg cocaine died of cardiorespiratory toxicity (p less than 0.03). Pseudocholinesterase activity (mean +/- SEM) of groups 1 and 2 were 0.6 +/- 0.2 and 7.3 +/- 0.7 units, respectively (p less than 0.01). Our results show that rats with lower pseudocholinesterase activity had lower fatality rates than rats with higher pseudocholinesterase activity.
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PMID:Inhibition of pseudocholinesterase activity protects from cocaine-induced cardiorespiratory toxicity in rats. 847 99

An analytical method was developed with sensitivity to detect clinically significant concentrations of heptylphysostigmine (HP), a new physostigmine derivative with potent and long-lasting inhibitory activity on cholinesterase. HP, an experimental drug for Alzheimer disease, was measured in human plasma by high-performance liquid chromatography with electrochemical detection with use of a normal-phase column and acetonitrile buffer containing tetrahydrofuran and sodium acetate, pH 4.6. The limit of detection of the method was 0.125 ng/ml using a 2-ml sample of plasma. Analytical recovery of HP was 53.04 +/- 7.75% for plasma in the range 0.25-2.5 ng/ml. Stability studies conducted at 37 degrees C indicated that the drug was stable in 1 M hydrochloric acid, 1 M hydrogen peroxide and sodium acetate-buffered solution at pH 4 for at least 6 h but at pH 7 it degraded slightly to 79% at 6 h and was unstable in 1 M sodium hydroxide with only 9% of the parent compound remaining at 30 s. HP was stable when exposed to ultraviolet light at 22 degrees C or 100% relative humidity at 37 degrees C, with almost 80 and 75% of the parent compound remaining after 4 and 28 days, respectively. HP was stable in plasma at 4 degrees C for 0.25 h, and it slowly degraded to 56 and 28% of the original concentration by 1 and 2 h, respectively. HP was highly unstable in plasma at higher temperatures; at 22 and 37 degrees C it degraded immediately to 48 and 36% of the original concentration and was not detected after 0.5 and 0.25 h, respectively.
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PMID:Determination of heptylphysostigmine in plasma by high-performance liquid chromatography with electrochemical detection. 160 60

Alterations in erythrocyte plasma membrane properties (enzymatic activities and membrane fluidity) have been observed in patients affected by insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). In order to verify whether these alterations are present also in gestational diabetes mellitus (GDM) we studied the plasma membranes obtained from two different cellular types (erythrocyte from both mother and cord blood and placenta syncytiothrophoblast cell) of 16 healthy pregnant women and 15 women affected by GDM. The following determinations were performed on the membrane preparations: Na+/K(+)-ATPase activity, acetyl-cholinesterase (AchE) activity, membrane fluidity and cholesterol:phospholipid ratio. We observed a reduction of both enzymatic activities and a decrease of membrane fluidity in maternal and cord blood erythrocytes and in syncytiotrophoblast plasma membranes in GDM pregnant women in comparison with controls. The cholesterol to phospholipid ratio was significantly lower in the erythrocyte membranes of women affected by GDM than in normal pregnant women, while it was increased in the cord blood erythrocyte membranes and in placental membranes in GDM in comparison with controls. The present study found, in GDM patients, a membrane alteration similar to the abnormality reported in IDDM and NIDDM (i.e. decreased Na+/K(+)-ATPase activity), while opposite modifications were observed with regard to other membrane activities and properties. The different membrane alterations observed in GDM with respect to IDDM and NIDDM might be linked to the different degree of metabolic control, on the contrary the reduced Na+/K(+)-ATPase activity might be a primary event in the pathogenesis of diabetes mellitus per se and might constitute a signal of high risk of developing the disease later in the women affected by GDM during pregnancy.
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PMID:Modifications induced by gestational diabetes mellitus on cellular membrane properties. 165 18

1. Acetylcholine (ACh), 7.5 x 10(-5) M, and carbachol, 5 x 10(-6) M (CCh) depressed the frequency of miniature endplate potentials (m.e.p.ps) in the frog (Rana temporaria) sartorius neuromuscular junction with active acetylcholinesterase to about 50-55% of the controls. 2. A similar depression was produced by the nicotinic agonists, nicotine, suberyldicholine and tetramethylammonium. 3. The muscarinic agonists, oxotremorine, methylfurmethide and methacholine were without effect on m.e.p.p. frequency. The muscarinic antagonist, atropine and the nicotinic antagonist, (+)-tubocurarine, had no effect on the depression of m.e.p.p. frequency evoked by CCh. 4. The ganglionic blockers, benzhexonium and IEM-1119, were also without effect on the CCh-evoked depression of m.e.p.p. frequency. 5. Pretreatment of muscles with anticholinesterases did not prevent the CCh-induced drop in m.e.p.p. frequency. 6. The effect of CCh was proportionally the same as in the controls in preparations where the m.e.p.p. frequency was changed by elevation of K+ and in the presence of theophylline, noradrenaline, dibutyryl adenosine 3':5'-cyclic monophosphate (db cyclic AMP) and db cyclic GMP. 7. An inhibitor of Na+,K(+)-ATPase, ouabain, 5 x 10(-5) mol l-1, prevented or reversed the depression of m.e.p.p. frequency by CCh. However, the depression was present in a nominally K(+)-free medium. Insulin and adrenaline, which are considered to be Na+,K(+)-ATPase activators, were without effect on depression of m.e.p.p. frequency. 8. The depression of m.e.p.p. frequency by 5 x 10(-6) M CCh was the same at temperatures between 5 and 30 degrees C with a Q10 near to 1.0. When threshold amounts of CCh were used (6 x 10-7 and 3 x 10-7 M), the depression was less at higher temperatures.9. The receptive structures responsible for the CCh (or ACh)-evoked depression of m.e.p.p. frequency differ pharmacologically from muscarinic, nicotinic ganglionic and neuromuscular junction ACh-receptors as well as from the synaptic cholinesterase, in contrast to previous reports (Duncan & Publicover, 1979).The low temperature-dependence points to the possibility that physical rather than biochemical processes are limiting in this presynaptic effect of cholinomimetics.
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PMID:Depression of miniature endplate potential frequency by acetylcholine and its analogues in frog. 166 83


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