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)

Bi-enzyme sensor based on thick-film epoxy-carbon electrode modified with polytyramine has been developed and examined for the determination of peroxidase substrates and cholinesterase inhibitors. Polytyramine was obtained on the electrode surface by repeated scanning of the potential from +600 to +1800 mV vs. Ag/AgCl in tyramine solution. The enzymes were immobilized in the polytyramine matrix by cross-linking with glutaraldehyde. The biosensor developed provides a reliable and inexpensive way for preliminary testing of common environmental pollutants with a single sensor in accordance with assumed toxic effect by the choice of appropriate substrate and measurement conditions. The bi-enzyme sensor makes it possible to determine substituted phenols and aromatic amines in the micromolar range of their concentrations and anticholinesterase pesticides with detection limits of 0.1 (Coumaphos) and 0.03 micromol l(-1) (Chloropyrifos-methyl).
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PMID:Bi-enzyme sensor based on thick-film carbon electrode modified with electropolymerized tyramine. 1511 Feb 88

Intrathecal (IT) injection of neostigmine (a cholinesterase inhibitor) has been reported to produce a significant anti-nociceptive effect in a number of inflammatory pain models. However, a potential anti-inflammatory effect of IT neostigmine in these models has not been investigated. In the present study, we have examined the 'anti-inflammatory effect of IT injection of neostigmine' (AI-NEO) using a standard mouse air pouch model by evaluating the effect of AI-NEO on zymosan-induced leukocyte migration and myeloperoxidase (MPO) release. IT neostigmine was found to suppress both leukocyte migration and MPO degranulation in a dose dependent manner. We then established which subtypes of cholinergic receptors were involved in this AI-NEO. IT pretreatment with atropine (a muscarinic receptor antagonist) but not hexamethonium (a nicotinic receptor antagonist) completely blocked the IT neostigmine anti-inflammatory effect. Subsequent experiments showed that IT pretreatment with methoctramine (a muscarinic type 2 (M2) receptor antagonist), but not pirenzepine (M1 receptor antagonist) or 4-DAMP (M3 receptor antagonist), suppressed the AI-NEO. We then evaluated whether adrenal glandular activity was important in the AI-NEO. Adrenalectomy significantly blocked the AI-NEO, while intraperitoneal pretreatment with the beta-adrenoceptor antagonist (propranolol), but not the corticosteroid antagonist (RU486) reversed AI-NEO. In conclusion, these results indicate that IT neostigmine facilitates the activation of spinal M2 receptors and this activation ultimately leads to release of adrenal catecholamines which contribute to the anti-inflammatory effect observed at the site of tissue inflammation.
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PMID:Intrathecal neostigmine reduces the zymosan-induced inflammatory response in a mouse air pouch model via adrenomedullary activity: involvement of spinal muscarinic type 2 receptors. 1592 70

Four wastewater samples of different treatment qualities; untreated, alarm, alert and normal, from a Swedish chemi-thermo-mechanical pulp mill and pure water were investigated using an amperometric bio-electronic tongue in a batch cell. The aim was to explore enzymatically modified screen-printed amperometric sensors for the discrimination of wastewater quality and to counteract the inherent drift. Seven out of eight platinum electrodes on the array were modified with four different enzymes; tyrosinase, horseradish peroxidase, acetyl cholinesterase and butyryl cholinesterase. At a constant potential the current intensity on each sensor was measured for 200s, 100s before injection and 100s after injection of the sample. The dynamic biosensor response curves from the eight sensors were used for principal component analysis (PCA). A simple baseline and sensitivity correction equivalent to multiplicative drift correction (MDC), using steady state intensities of reference sample (catechol) recordings, was employed. A clear pattern emerged in perfect agreement with prior knowledge of the samples explaining 97% of the variation in the data by two principal components (PCs). The first PC described the treatment quality of the samples and the second PC described the difference between treated and untreated samples. Horseradish peroxidase and pure platinum sensors were found to be the determinant sensors, while the rest did not contribute much to the discrimination. The wastewater samples were characterized by the chemical oxygen demand (COD), biological oxygen demand (BOD), total organic carbon (TOC), inhibition of nitrification, inhibition of respiration and toxicity towards Vibrio fischeri using Microtox, the freshwater alga Pseudokirchneriella subcapita and the freshwater crustacean Daphnia magna.
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PMID:Chemometric exploration of an amperometric biosensor array for fast determination of wastewater quality. 1620 74

Trichinosis is a parasitic infection affecting the gut and the muscles causing mild gastrointestinal symptoms followed by periorbital oedema, muscle pains, fever and eosinophilia. The infection evokes functional disturbances in physiological effector systems. Furthermore, several biochemical changes are associated with the infection. Therefore, this work was carried out to study the electrophysiological changes in intestine, striated and cardiac muscles by electromyography (EMG) and to assess the biochemical changes through measurement of serum cholinesterase and intestinal myeloperoxidase activity (MPO) in both light and heavy infected experimental animals by Trichinella spiralis (T. spiralis). Electrophysiological results showed increased contractility of the smooth muscle layers of the intestine only early in the infection, whereas both striated and cardiac muscles showed increase in the contractility with the progress of infection in both light and heavy infection. Significant myocardial dysfunction in the form of bradycardia, in addition to major histopathological changes in the heart occurred from the beginning of the infection and increased till the end of the study. Biochemical study showed gradual increase in serum cholinesterase, while, the intestinal MPO showed increase only in the early stage of the infection. It was noticed that all changes were more pronounced in the heavily infected group than the lightly infected one.
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PMID:Experimental trichinosis: parasitological, electrophysiological and biochemical studies. 1692 61

Extensive literature suggests that melatonin play a role against the degenerative effect of central neurotoxins by its acting as free radical scavenger. This study aimed at evaluation of the anti-mutagenic activity of novel synthesized indole derivatives 2, 4a, and 8 in albino male mice in comparison with the parent melatonin. Efficacy of melatonin and its derivatives to influence cyclophosphamide (CP)-induced genotoxicity was tested using micronuclei (MN) formation in the bone marrow cells and determination of DNA, RNA and protein levels as well as cholinesterase and peroxidase activities in several organs of male mice. Following intragastrical injection of melatonin or one of its derivatives daily for 1 week, CP was given intraperitoneally, i.p., as a single dose of 25mg/kg BW. Pyridazin-4-yl thiadiazoloindole derivative 8, diaminothiophen-5-yl thiadiazoloindole derivative 4a and melatonin were significantly able to reduce the number of micronucleated polychromatic erythrocytes (MnPCEs) in the bone marrow cells induced by CP (P<0.0001, P<0.001, P<0.01, respectively). However, reduction of MN formation in the bone marrow cells was not significant when thiadiazoloindole derivative 2 was administered (P=0.14). Examination of the protective effect of melatonin and its derivatives on the levels of DNA, RNA and protein as well as enzyme activities showed that compound 8 had the ability to inhibit the clastogenic effect of CP in several organs of male mice. These findings suggest that compounds 4a, 8 and melatonin were able to reduce the mutagenicity effect of CP in male mice. The ability of compounds 4a, 8 and melatonin to reduce CP-related genotoxicity is possibly attributed to their antioxidant activity.
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PMID:Synthesis and in vivo anti-mutagenic activity of novel melatonin derivatives. 1770 26

This study examined the effects of Y-27632, a selective Rho-kinase inhibitor, on organophosphate-induced acute toxicity in rats. Rats were randomly divided into four groups as control (corn oil), dichlorvos (30 mg kg(-1) i.p.), 1 and 10 mg kg(-1) Y-27632 + dichlorvos groups. Cholinergic signs (fatigue, tremor, cyanosis, hyper-secretion, fasciculations) were observed in all the rats in the dichlorvos group and the mortality rate was 50%. No cholinergic findings and deaths were observed in the control and Y-27632 groups. Plasma cholinesterase activities were suppressed with dichlorvos and these reductions were attenuated with Y-27632 pretreatment. There was a marked increase in plasma malondialdehyde level in the dichlorvos group, but Y-27632 pretreatment abolished this elevation. Dichlorvos markedly depressed cardiac paraoxonase activity, but these changes were not markedly modified with Y-27632. Total antioxidant capacities, total oxidant status, oxidative stress index, total free sulfhydryl groups and catalase activities in plasma and cardiac tissues were not markedly different between the groups. No significant changes were observed with cardiac myeloperoxidase activities or plasma arylesterase and ceruloplasmin activities. In conclusion, our results suggest that Rho-kinase pathway is involved in organophosphate intoxication, and a decrease in cardiac paraoxonase activities may play a role in the pathogenesis of acute organophosphate poisoning in rats.
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PMID:Effects of a selective Rho-kinase inhibitor Y-27632 on oxidative stress parameters in acute dichlorvos poisoning in rats. 1863 19

The screen-printed four-electrode system was used as the amperometric transducer for determination of phenols and pesticides using immobilised tyrosinase, peroxidase, acetylcholinesterase and butyrylcholinesterase. Acetylthiocholine chloride was chosen as substrate for cholinesterases to measure inhibition by pesticides, hydrogen peroxide served as co-substrate for peroxidase to measure phenols. The compatibility of hydrolases and oxidoreductases working in the same array was studied. The detection of p-cresol, catechol and phenol as well as of pesticides including carbaryl, heptenophos and fenitrothion was carried out in flow-through and steady state arrangements. In addition, the effects of heavy metals (Cu(2+), Cd(2+), Fe(3+)), fluoride (NaF), benzene and dimethylsulphoxide on cholinesterase activities were evaluated. It was demonstrated that electrodes modified with hydrolases and oxidoreductases can function in the same array. The achieved R.S.D. values obtained for the flow system were below 4% for the same sensor and less than 10% within a group of five sensors. For the steady state system, R.S.D.s were approximately twice higher. One assay was completed in less than 6min. The limit of detection for catechol using tyrosinase was equal to 0.35 and 1.7muM in the flow and steady state systems, respectively. On the contrary, lower limits of detection for pesticides were achieved in the steady state system-carbaryl 26nM, heptenophos 14nM and fenitrothion 0.58muM.
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PMID:Multienzyme electrochemical array sensor for determination of phenols and pesticides. 1896 6

Twelve rounds of systematic evolution of ligands by exponential enrichment (SELEX) were conducted against a magnetic bead conjugate of the para-aminophenylpinacolylmethylphosphonate (PAPMP) derivative of the organophosphorus (OP) nerve agent soman (GD). The goal was to develop DNA aptamers that could scavenge GD in vivo, thereby reducing or eliminating the toxic effects of this dangerous compound. Aptamers were sequenced and screened in peroxidase-based colorimetric plate assays after rounds 8 and 12 of SELEX. The aptamer candidate sequences exhibiting the highest affinity for the GD derivative from round 8 also reappeared in several clones from round 12. Each of the highest affinity PAPMP-binding aptamers also bound methylphosphonic acid (MPA). In addition, the aptamer with the highest overall affinity for PAPMP carried a sequence motif (TTTAGT) thought to bind MPA based on previously published data (J. Fluoresc 18: 867-876, 2008). This sequence motif was found in several other relatively high affinity PAPMP aptamer candidates as well. In studies with the nerve agent GD, pre-incubation of a large molar excess of aptamer candidates failed to protect human butyrylcholinesterase (BuChE) from inhibition. With the aid of three-dimensional molecular modeling of the GD derivative it appears that a hydrophilic cleft sandwiched between the pinacolyl group and the p-aminophenyl ring might channel nucleotide interactions to the phosphonate portion of the immobilized GD derivative. However, bona fide GD free in solution may be repulsed by the negative phosphate backbone of aptamers and rotate its phosphonate and fluorine moieties away from the aptamer to avoid being bound. Future attempts to develop aptamers to GD might benefit from immobilizing the pinacolyl group of bona fide GD to enhance exposure of the phosphonate and fluorine to the random DNA library.
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PMID:DNA aptamers developed against a soman derivative cross-react with the methylphosphonic acid core but not with flanking hydrophobic groups. 1905 Dec 3

This study was carried out to investigate the neurotoxic and immunotoxic effects of Indole-3-butyric acid (IBA), a plant growth regulator (PGR), on rats at subacute and subchronic exposure. The neurotoxic effects of IBA were evaluated by measuring the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Biomarkers selected for immunotoxic monitoring were the activities of adenosine deaminase (ADA) and myeloperoxidase (MPO) in various tissues of rats exposed to 25 and 50 ppm dosages of IBA for 20 and 45 days. Results showed that the administrations of IBA decreased AChE and BChE activities in some tissues of the rats treated with both dosages and periods of IBA. With regard to the immunotoxic effects, ADA activity significantly decreased whereas MPO activity increased after subacute and subchronic exposure with both dosages in most of the tissues of rats compared with controls. The observations presented led us to conclude that the administrations of IBA at subacute and subchronic exposure decreased AChE, BChE and ADA activities whereas increased MPO activity in various tissues of rats. This may reflect the potential role of these parameters as useful biomarkers for toxicity of IBA.
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PMID:Neurotoxic and immunotoxic effects of Indole-3-butyric acid on rats at subacute and subchronic exposure. 1944 22

This study was carried out to investigate the neurotoxic and immunotoxic effects of trichloroacetic acid (TCA) on rats at subchronic exposure. The neurotoxic effects of TCA were evaluated by measuring the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Biomarkers selected for immunotoxic monitoring were the activities of adenosine deaminase (ADA) and myeloperoxidase (MPO) in various tissues of rats exposed to 2000 parts per million (ppm) dosage of TCA for 52 days. Results showed that the administrations of TCA decreased BChE activities in heart and lungs tissue of the rats treated with TCA. With regard to the immunotoxic effects, ADA activity significantly decreased in the heart, lungs and spleen whereas MPO activity increased after subchronic exposure with 2000 ppm dosage in all of the tissues except for heart tissue of rats compared with controls. The observations presented led us to conclude that the administration of TCA at subchronic was decreased BChE and ADA activities whereas increased MPO activity in various tissues of rats. This may reflect the potential role of these parameters as useful biomarkers for toxicity of TCA.
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PMID:Evaluation of neurotoxic and immunotoxic effects of trichloroacetic acid on rats. 2063 59


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