Butyrylcholinesterase Concentration Research Articles

Peripheral cholinesterase activity is not correlated with postoperative delirium in urological surgery.

The value of biomarkers, such as acetylcholinesterase and butyrylcholinesterase, for guiding perioperative patients suffering from postoperative delirium and/or (possibly related) postoperative cognitive dysfunction is unclear. Only recently have different biomarkers are being explored to assess postoperative delirium's occurrence and/or course. The aim of this work is to investigate whether acetylcholinesterase and butyrylcholinesterase can help detect increased risks of the development and course of postoperative delirium in urological patients undergoing surgery. In total, 45 urology patients were screened. During five perioperative time points (meaning preoperative and postoperative), acetylcholinesterase or butyrylcholinesterase concentrations from serum were correlated with three perioperative postoperative delirium and two perioperative postoperative cognitive dysfunction investigations. Results showed neither a significant decline of either acetylcholinesterase or butyrylcholinesterase concentration before and after surgery, nor a significant correlation with postoperative delirium. Furthermore, significant postoperative cognitive dysfunction could not be detected in this perioperative urological collective.

Dual-Mode Ratiometric Electrochemical and Turn-On Fluorescent Detection of Butyrylcholinesterase Utilizing a Single Probe for the Diagnosis of Alzheimer's Disease.

Biomarkers detection in blood with high accuracy is crucial for the diagnosis and treatment of many diseases. In this study, the proof-of-concept fabrication of a dual-mode sensor based on a single probe (Re-BChE) using a dual-signaling electrochemical ratiometric strategy and a "turn-on" fluorescent method is presented. The probe Re-BChE was synthesized in a single step and demonstrated dual mode response toward butyrylcholinesterase (BChE), a promising biomarker of Alzheimer's disease (AD). Due to the specific hydrolysis reaction, the probe Re-BChE demonstrated a turn-on current response for BChE at -0.28 V, followed by a turn-off current response at -0.18 V, while the fluorescence spectrum demonstrated a turn-on response with an emission wavelength of 600 nm. The developed ratiometric electrochemical sensor and fluorescence detection demonstrated high sensitivity with BChE concentrations with a low detection limit of 0.08 μg mL-1 and 0.05 μg mL-1, respectively. Importantly, the dual-mode sensor presents the following advantages: (1) dual-mode readout can correct the impact of systematic or background error, thereby achieving more accurate results; (2) the responses of dual-mode readout originate from two distinct mechanisms and relatively independent signal transduction, in which there is no interference between two signaling routes. Additionally, compared with the reported single-signal electrochemical assays for BChE, both redox potential signals were detected in the absence of biological interference within a negative potential window. Furthermore, it was discovered that the outcomes of direct dual-mode electrochemical and fluorescence quantifications of the level of BChE in serum were in agreement with those obtained from the use of commercially available assay kits for BChE sensing. This method has the potential to serve as a useful point-of-care tool for the early detection of AD.

Does butyrylcholinesterase mediate exercise-induced and meal-induced suppression in acylated ghrelin?

Ample evidence supports the notion that an acute bout of aerobic exercise and meal consumption reduces acylated ghrelin concentration. However, the mechanisms by which this exercise- and meal-induced suppression of acylated ghrelin occurs in humans is unknown. This study aimed to examine the concentration of butyrylcholinesterase (BChE), an enzyme responsible for hydrolysing ghrelin and other appetite-related hormones in response to a single bout of running and a standardised meal in young, healthy men. Thirty-three men (aged 23 ± 2 years, mean ± standard deviation) underwent two (exercise and meal conditions) 2-h laboratory-based experiments. In the exercise condition, all participants ran for 30 min at 70% of the maximum oxygen uptake (0930-1000) and rested until 1130. In the meal condition, participants reported to the laboratory at 0930 and rested until 1000. Subsequently, they consumed a standardised meal (1000-1015) and rested until 1130. Blood samples were collected at baseline (0930), 1000, 1030, 1100 and 1130. BChE concentration was not altered in both the exercise and meal conditions (p > 0.05). However, acylated ghrelin was suppressed after exercise (p < 0.05) and meal consumption (p < 0.05). There was no association between the change in BChE concentration and the change in acylated ghrelin before and after exercise (p = 0.571). Although des-acylated ghrelin concentration did not change during exercise (p > 0.05), it decreased after meal consumption (p < 0.05). These findings suggest that BChE may not be involved in the suppression of acylated ghrelin after exercise and meal consumption.

Point-of-care testing of butyrylcholinesterase activity through modulating the photothermal effect of cuprous oxide nanoparticles.

Butyrylcholinesterase (BChE) is an important indicator for clinical diagnosis of liver dysfunction, organophosphate toxicity, and poststroke dementia. Point-of-care testing (POCT) of BChE activity is still a challenge, which is a critical requirement for the modern clinical diagnose. A portable photothermal BChE assay is proposed through modulating the photothermal effects of Cu2O nanoparticles. BChE can catalyze the decomposition of butyrylcholine, producing thiocholine, which further reduce and coordinate with CuO on surface of Cu2O nanoparticle. This leads to higher efficiency of formation of Cu9S8 nanoparticles, through the reaction between Cu2O nanoparticle and NaHS, together with the promotion of photothermal conversion efficiency from 3.1 to 59.0%, under the excitation of 1064nm laserradiation. An excellent linear relationship between the temperature change and the logarithm of BChE concentration is obtained in the range 1.0 to 7.5 U/mL, with a limit of detection of 0.076 U/mL. In addition, the portable photothermal assay shows strong detection robustness, which endows the accurate detection of BChE in human serum, together with the screening and quantification of organophosphorus pesticides. Such a simple, sensitive, and robust assay shows great potential for the applications toclinical BChE detection andbrings a new horizon for the development of temperature based POCT.

Steady-State Kinetics of Enzyme-Catalyzed Hydrolysis of Echothiophate, a P-S Bonded Organophosphorus as Monitored by Spectrofluorimetry.

Enzyme-catalyzed hydrolysis of echothiophate, a P–S bonded organophosphorus (OP) model, was spectrofluorimetrically monitored, using Calbiochem Probe IV as the thiol reagent. OP hydrolases were: the G117H mutant of human butyrylcholinesterase capable of hydrolyzing OPs, and a multiple mutant of Brevundimonas diminuta phosphotriesterase, GG1, designed to hydrolyze a large spectrum of OPs at high rate, including V agents. Molecular modeling of interaction between Probe IV and OP hydrolases (G117H butyrylcholinesterase, GG1, wild types of Brevundimonas diminuta and Sulfolobus solfataricus phosphotriesterases, and human paraoxonase-1) was performed. The high sensitivity of the method allowed steady-state kinetic analysis of echothiophate hydrolysis by highly purified G117H butyrylcholinesterase concentration as low as 0.85 nM. Hydrolysis was michaelian with Km = 0.20 ± 0.03 mM and kcat = 5.4 ± 1.6 min−1. The GG1 phosphotriesterase hydrolyzed echothiophate with a high efficiency (Km = 2.6 ± 0.2 mM; kcat = 53400 min−1). With a kcat/Km = (2.6 ± 1.6) × 107 M−1min−1, GG1 fulfills the required condition of potential catalytic bioscavengers. quantum mechanics/molecular mechanics (QM/MM) and molecular docking indicate that Probe IV does not interact significantly with the selected phosphotriesterases. Moreover, results on G117H mutant show that Probe IV does not inhibit butyrylcholinesterase. Therefore, Probe IV can be recommended for monitoring hydrolysis of P–S bonded OPs by thiol-free OP hydrolases.

Correlation of plasma butyrylcholinesterase concentration with Acethylcholinesterase H353N polymorphism in the inflammatory response of Chagas disease patients

Trypanosoma cruzi infection triggers an intense production of pro-inflammatory cytokines mediated by T helper 1 lymphocytes, inducing the anti-inflammatory reflex of acetylcholine (ACh). The ACh concentration modulation is associated to the two major esterases, the acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). AChE H353N protein polymorphism is related to low Chagas chronic disease prognostic. In order to evaluate the correlation of plasmatic BuChE concentration and the presence of AChE H353N polymorphism in Chagas disease patients and healthy individuals, we studied two groups of individuals, one of 61 Chagas disease patients and another of 74 healthy individuals. Plasma concentration of BuChE was measured by the chemiluminescent method and AChE H353N polymorphism was investigated by PCR-RFLP and sequencing of the respective encoding AChE gene fragment. The BuChE concentration was statistically higher in Chagas disease patients, with no AChE genotype significant influence. AChE genotypes YT*A/YT*A, YT*A/YT*B and YT*B/YT*B, respectively, were expressed in 53 (86.88%), 7 (11.46%) and one (1.64%) chagasic patients, and in 68 (91.89%), 6 (8.10%) and none healthy individuals. BuChE activity may represent an important marker for chronic Chagas disease inflammatory process and prognostic. Lower BuChE concentration correlated with AChE YT*B allele, although without statistical power.

Enzymatic reaction modulated synthesis of quantum dots for visual detection of cholinesterase activity and inhibitor

An enzyme-activable modulated synthesis of fluorescent CdTe quantum dots (QDs) strategy was developed in this work. Monitoring the in-situ growth of CdTe QDs is shown to be a novel route to label-free and visual detect butyrylcholinesterase (BChE), an important enzyme in human bodies. BChE can catalyze butyrylcholine (BTCh) to produce thiocholine (TCh), which is an excellent thio-ligand during CdTe QDs growths. Therefore, BChE can activate the thio-ligand via enzymolysis thus trigger the growth of luminescent QDs. As the BChE concentration was proportional to the fluorescence intensity of the QDs, the activity of BChE was detected accordingly. Under the optimized experimental conditions, the limit of detection (LOD) of BChE was found to be 0.96 U L−1. The relative standard deviation (RSD) (n = 7) was 1.8%. What’s more, parathion, one of the organophosphorus pesticides (OPs), which inhibits the activity of BChE, was used to prevent the generation of thiocholine and therefore inhibits the growth of QDs. As a result, this sensing system can also present a turn off mode for the parathion detection with highly sensitivity (LOD = 0.38 ng mL−1). Furthermore, visual detection was realized for BChE and parathion in this strategy, 40 U L−1 of BChE and 2 ng mL−1 of parathion can be discriminated from the blank solution with the naked eye, respectively.

Butyrylcholinesterase blood plasma concentrations of Common Swifts (Apus apus)

Butyrylcholinesterase (BChE), known as pseudocholinesterase or plasma cholinesterase, is a non-specific cholinesterase enzyme synthesised in the liver. The function of this enzyme is unknown in detail and is primarily discussed as a safeguarding system for Acetylcholinesterase (AChE). In a retrospective analysis of results of blood chemistry investigations of wild bird patients of the Clinic for Small Mammals, Reptiles and Birds, University of Veterinary Medicine Hannover, Foundation, Germany, BChE plasma concentrations of the Common Swift (Apus apus) and a possible influence of the body condition and age were determined. Blood values of adult (n = 33) and juvenile (n = 50) Common Swifts were analysed. BChE was determined by dry chemistry analyser Kodak Ektachem DTSC II module® with slides with butyrylthiocholin as substrate and measured at 400 nm by reflectance spectrophotometry during 5-min incubation at 37 °C. The Common Swift could be determined as a species with very high BChE blood plasma concentrations compared to other insectivore species. The arithmetic mean ± standard deviation (SD) for adult swifts amounted to 27,189.28 U/l ± 10,852.94 and that for juvenile/fledged swifts to 25,986.54 U/l ± 9573.28. A remarkable influence of the body condition on this BChE plasma concentration could be observed. In cases of malnutrition, a highly significant decrease of BChE activity could be found. For example, BChE concentrations of adult swifts in a poor body condition with reduced total protein and albumin blood plasma concentrations without liver diseases, arithmetic mean ± SD, 14,837.13 U/ l ± 7944.45, illustrate this impact.

Butyrylcholinesterase as an additional marker in the diagnostic network of acute myocardial infarction

Abstract Background: Acute coronary syndrome defines a broad spectrum of complaints from angina to irreversible myocardial damage. There is an ongoing need for a biomarker to predict and diagnose acute myocardial infarction (AMI) in the early stage. In this study, our aim was to reveal early diagnostic value of butyrylcholinesterase (BChE) in discrimination of healthy subjects and patients with AMI. Methods: Eighty-five patients admitted to our hospital due to AMI and 45 healthy subjects were involved in the study. Patients and controls were compared according to BChE, lipid profiles and biochemical parameters. Results: The serum BChE activity was significantly lower in patients with AMI than in the controls (p&lt;0.001). After correlation analysis, while a negative correlation was determined between the serum BChE concentrations and AMI presence (r=–0.363, p&lt;0.001); a positive correlation was determined between the serum BChE and cholesterol (r=0.443, p&lt;0.001), HDL (r=0.243, p=0.006) and LDL (r=0.369, p&lt;0.001) levels. The data indicate that BChE is associated with AMI and a subsequent receiver operating characteristic curve (ROC) analysis revealed that BChE, as an independent indicator, may differentiate AMI patients from controls. A cut-off point set at ≤7.15 kIU/L, BChE showed a sensitivity of 51.2% and a specificity of 84.4% (AUC=0.719, p&lt;0.001). Conclusions: Low BChE level was significantly associated with AMI when compared to healthy subjects. Even though it has low sensitivity, plasma levels of BChE might represent an additional marker in the diagnostic network of AMI.

Plasma butyrylcholinesterase concentrations in psittacine birds: reference values, factors of variation, and association with feather-damaging behavior.

Butyrylcholinesterase is a glycoprotein enzyme used in the diagnosis of toxicosis by cholinesterase-inhibitor agents like organophosphates and carbamates. In animals, butyrylcholinesterase concentrations have been shown to vary depending on numerous factors such as age, sex, diet, and season of sampling. To establish reference values of plasma butyrylcholinesterase concentrations in common psittacine species, plasma butyrylcholinesterase concentrations were measured in 1942 companion psittacine birds. The birds were classified by age, sex, season, health status, and the presence of feather-damaging behavior. A significant difference was observed among species, with eclectus parrots (Eclectus roratus) having the lowest and African grey parrots (Psittacus erithacus) having the highest reference values. Plasma butyrylcholinesterase concentrations varied by age, health status, and season but not by sex. Concentrations were significantly higher during autumn and spring than during winter and summer, and significantly lower in healthy birds than in sick birds. No significant association between butyrylcholinesterase concentrations and feather-damaging behavior could be established except in lovebirds (Agapornis species). Further research is needed to better understand the effect of nutritional and hormonal factors on butyrylcholinesterase concentrations in psittacine birds and its possible effect on bird cognition.

Performance of a portable biosensor for the analysis of ethion residues

Sensitive disposable potentiometric sensors for determination of the organophosphorus pesticide (OPs), ethion and its degradation residues have been constructed. The fabricated screen printed sensors are based on multi-walled carbon nanotube-polyvinyl chloride (MWNT-PVC) composite incorporated with α-cyclodextrin (α-CD) ionophore for butyrylcholine (BuCh) determination. Butyrylcholinesterase (BuChE) activity was measured through monitoring the BuCh hydrolysis using the fabricated sensors. The electrode potential changes linearly with BuChE concentration over the range from 0.04 to 0.4 U in phosphate buffer solution. This approach can also be used to analyze ethion and its degradation products in the concentration range from 0 to 330 ng mL(-1) by measuring the relative inhibition percentage of BuChE. From different ethion degradation products, inhibition by dioxon and monooxon were more potent than the parent pesticide. The proposed method was applied for determination of ethion in different samples with good accuracy and precision. The relative simple fabrication protocol of biosensor, high sensitivity and stability represents a promising approach for determination of environmental pollutants in field conditions.

Magnetic Electrochemical Sensing Platform for Biomonitoring of Exposure to Organophosphorus Pesticides and Nerve Agents Based on Simultaneous Measurement of Total Enzyme Amount and Enzyme Activity

We report a new approach for electrochemical quantification of enzymatic inhibition and phosphorylation for biomonitoring of exposure to organophosphorus (OP) pesticides and nerve agents based on a magnetic bead (MB) immunosensing platform. The principle of this approach is based on the combination of MB immunocapture-based enzyme activity assay and competitive immunoassay of the total amount of enzyme for simultaneous detection of enzyme inhibition and phosphorylation in biological fluids. Butyrylcholinesterase (BChE) was chosen as a model enzyme. In competitive immunoassay, the target BChE in a sample competes with the BChE immobilized on the MBs to bind to the limited sites of anti-BChE antibody labeled with quantum dots (QD-anti-BChE), followed by stripping voltammetric analysis of the bound QD conjugate on the MBs. This assay shows a linear response over the total BChE concentration range of 0.1-20 nM. Simultaneous real time BChE activity was measured on an electrochemical carbon nanotube-based sensor coupled with a microflow injection system after immunocapture by the MB-anti-BChE conjugate. Therefore, the formed phosphorylated BChE adduct (OP-BChE) can be estimated by the difference values of the total amount of BChE (including active and OP-inhibited) and active BChE from established calibration curves. This approach not only eliminates the difficulty in screening of low-dose OP exposure (less than 20% inhibition of BChE) because of individual variation of BChE values but also avoids the drawback of the scarce availability of OP-BChE antibody. It is sensitive enough to detect 0.5 nM OP-BChE, which is less than 2% BChE inhibition. This method offers a new method for rapid, accurate, selective, and inexpensive quantification of OP-BChE and enzyme inhibition for biomonitoring of OP and nerve agent exposures.

Relationship between serum butyrylcholinesterase and obesity in dogs: A preliminary report

The aim of this study was to analyse serum butyrylcholinesterase (BChE) values in experimentally developed obesity in Beagle dogs. A short-term fattening protocol was applied to 11 dogs to obtain a wide range of bodyweight (BW) gains and body condition scores (BCS) of 4 and 5; four other dogs with BCS scores of 3 were used as controls. A significant increase in serum BChE activity in overweight dogs was observed when compared with the group of optimal weight dogs. Significant correlation was detected between BChE and BCS (r=0.911), BW (r=0.538) and morphological parameters (waist and thorax circumference, r=0.563 and r=0.552, respectively). Serum BChE concentration had a negative correlation with adiponectin concentration (r=0.719) and a positive correlation with serum lipid profile (cholesterol (r=0.781), HDL-cholesterol (r=0.763), LDL-cholesterol (r=0.878)). It was concluded that serum BChE activity is increased in experimentally overweight dogs and is correlated with other physical and biochemical markers of obesity.

Polymeric Membrane Ion‐Selective Electrode for Butyrylcholinesterase Based on Controlled Release of Substrate

AbstractA butyrylcholine selective polymeric membrane electrode using o‐β‐cyclodextrin as ionophore is described as a reagent controlled‐release system for reagentless detection of butyrylcholinesterase. Butyrylcholine released across the membrane from inner filling solution of the ion selective electrode is consumed by reaction of the enzyme in sample solution and the concentration of butyrylcholine at the membrane surface can be sensed potentiometrically. The electrode with 0.01 M butyrylcholine in the inner solution yields a potential that varies linearly with butyrylcholinesterase concentration over the range of 0.0075–0.15 U mL−1 in 0.02 M of pH 7.4 sodium phosphate buffer solution. This approach can also be used to analyze butyrylcholinesterase inhibitors such as organophosphate pesticides. The inhibition percentage of parathion is proportional to its concentration in the range of 0.05–0.5 ng mL−1 with a detection limit of 0.03 ng mL−1.

The influence of plasma butyrylcholinesterase concentration on the in vitro hydrolysis of cocaine in human plasma.

In humans, the plasma enzyme butyrylcholinesterase, BChE (EC 3.1.1.8), mediates the in vivo plasma hydrolysis of cocaine to the pharmacologically inactive metabolite ecgonine methyl ester, EME. This enzyme has been purified from human plasma to investigate the potential as a treatment for cocaine intoxication. Cocaine (2.1 micrograms mL-1) was incubated in plasma with a BChE concentration in the normal range (3.02 micrograms mL-1) and in plasma with enhanced BChE concentrations of 9.14, 20.8 and 37.8 micrograms mL-1, respectively for time periods up to 120 min. Cocaine and the hydrolytic products, ecgonine methyl ester and ecgonine, were quantified simultaneously by gas chromatography-mass spectrometry (GC-MS). The enhancement of plasma BChE concentration resulted in a dramatic increase in the rate of hydrolysis of cocaine. There was a stoichimetric conversion of cocaine to the inactive hydrolysis product, ecgonine methyl ester. Accordingly, the half-life of cocaine in plasma decreased significantly with enhanced BChE concentration. At plasma BChE concentrations of 3.02, 9.14, 20.8 and 37.8 micrograms mL-1, half-life values of 116, 35.8, 21.4 and 9.0 min, respectively were observed. The marked reduction in cocaine half-life provides evidence supporting the potential therapeutic use of BChE for the treatment of cocaine intoxication.

Combined analysis of acetylcholinesterase and alpha-fetoprotein improves the accuracy of antenatal diagnosis of neural-tube defects.

Acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and alpha-fetoprotein (AFP) were measured in 293 amniotic fluids from the second and third trimesters of pregnancy in a prospective study of their diagnostic value in the detection of neural-tube defects (NTD). In normal samples, the mean AChE and BChE concentrations were 3.0 u/L (SEM = 9.1 u/L) and 15.2 u/L (SEM = 1.2 u/L) in the second trimester, and 1.6 u/L (SEM = 0.1 u/L) and 7.8 u/L (SEM = 0.6 u/L) in the third trimester. AFP levels fell throughout the second trimester to unmeasurable levels in the third. AChE levels were markedly elevated in samples from NTD pregnancies at all gestational ages, and a cut-off level of the mean + 3 SD optimally separated normal from abnormal samples. This cut-off correctly predicted 10 of 11 fetuses with neural lesions; there were three false positive results. A similar cut-off for AFP predicted nine of 11 cases of neural lesion with two false positive results. For BChE, a cut off of 50 u/L predicted eight of 11 neural lesions with two false positive results. The specificity, sensitivity, and predictive value positive (PVP) were calculated for each test. The assays of AFP and AChE were useful when used individually (PVP congruent to 80%), but a Bayesian combination of these two tests produced a superior PVP (98%). Because the cost of AChE assay is low, and the test is so simple, it is suggested that an AChE analysis should be performed whenever an amniocentesis is requested for the diagnosis of NTD.