Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of acute poisoning with Dursban (O.P.I.) and D.D.T. (O.cl.I.) on serum enzymes and histopathological examination of the liver, kidney and testes was investigated in albino rats. Two repeated i.p. injections of Dursban in a dose of half the LD 50 resulted in a significant increase in serum GOT, GPT and alkaline phosphatase activity and a decrease of cholinesterase. In case of DDT, two doses of 150 mg/kg orally resulted in a significant increase in the activity of serum GPT only, while three doses increased serum GOT and GPT. No significant change was observed in serum alkaline phosphatase and cholinesterase activity. Regarding the pathological examination it was found that in animals treated with Dursban there was liver necrosis of mid-zonal type and fatty change at the periphery. In case of DDT the liver cells lost their radial arrangements and showed fatty change. There was cellular infiltration in the centre, mostly mononucleolar cells. In both insecticides there was necrosis of some of the seminiferous tubules of the testes and cloudy swelling of the convoluted tubules of the kidney. Histochemical study of the liver in animals treated with Dursban showed that glycogen was deposited at one side of the cell. However, there was depletion of glycogen around the central vein. In liver treated with DDT there were large globules of fat inside the liver cells, indicating increased fat content compared to control liver, where there were tiny minute droplets of fat.
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PMID:Acute toxicity of organophosphorus and organochlorine insecticides in laboratory animals. 9 70

When the insecticide parathion was administered to awake, unrestrained rats with chronically implanted brain electrodes, it was observed that the latency of the averaged flash-evoked potential in the visual cortex and superior colliculus was increased and the amplitude was decreased 2 to 4 hours later with responses returning to pretreatment levels about 8 hours after administration. Similarly, after administration of several dose levels of parathion in the rat, durations of phases of the maximal electroshock seizure (MES) pattern were altered to the greatest extent 4 hours later, but effects disappeared at 24 hours. These effects of parathion on the MES and evoked potentials coincided with a fall in blood and brain acetylcholinesterase (AChe) activities but disappeared after AChe inhibition had reached its peak and stabilized. Brain AChe activities required 2 to 4 weeks for recovery whereas blood AChe activity recovered in 1 week following inhibition by parathion (at least 2 mg/kg body weight). Studies in the monkey demonstrated similar results. Because these measurements of central nervous system function returned to normal despite continued inhibition of AChe activity, the results are interpreted to mean either that adaptation of evoked potentials or MES responses to prolonged AChe inhibition can occur in the rat and monkey after parathion administration or that some of the effects of parathion do not depend on AChe inhibition. Administration of DDT (100 mg/kg by mouth) to awake, unrestrained rats markedly increased the amplitude of spontaneous electrical activity in the cerebellum, whereas there was much less effect on electrical activity recorded simultaneously in the occipital cortex, reticular formation, and medial geniculate body. Similarly, DDT administration had marked effects on the averaged, sound evoked potential recorded in the cerebellum; DDT caused the appearance and increased the amplitude of an early component of this response not usually present during control recordings. Sound-evoked potentials recorded simultaneously from the frontal and occipital cortex and reticular formation were affected less or were decreased in amplitude by administration of DDT.
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PMID:Some aspects of neurophysiological basis of insecticide action. 18 31

1. Polyacrylamide gel electrophoresis in Tris/glycine buffer (pH 8.3) revealed five forms of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) in the 100 000 X g, 1-h supernatants of aqueous fly-head extracts from the DDT/S strain. Five other housefly strains (CSMA, Bayer 21/199, Cradson/P, Malathion/R and DDT/R)were shown qualitatively to have the same soluble forms of the enzyme. 2. Plots of the electrophoretic mobility versus polyacrylamide concentration indicated that the multiple forms constituted a size isomer family. From the retardation coefficients derived from these plots, molecular weight estimates were obtained; these suggested that the smallest active component was a form of approx. 80 000 daltons. The higher aggregates, however, did not appear as simple oligomers of this component. 3. Density gradient sedimentation supported the electrophoretic findings. The smallest active component, with a sedimentation coefficient of 5.3 S, was confirmed as a molecular species of acetylcholinesterase that has not previously been obtained from house-flies; higher aggregates gave sedimentation coefficients of 7.4, 7.8. 8.1, and 11.8 S. 4. Gel-filtration on calibrated Sephadex G-150 columns provided further evidence that the smallest active component was a form of about 80 000 daltons. 5. Autolysis converted much of the particulate enzyme and all of the soluble forms into a species of approx. 160 000 daltons indistinguishable from the native 7.4-S form. Both the autolysed enzyme and the native 7.4-S form were susceptible to cleavage by disulphide reducing agents, and released catalytically active subunits that corresponded to the 5.3-S form of 80 000 daltons. The data were compatible with a monomer-dimer relationship between the 5.3-S and 7.4-S forms. 6. The possibility is suggested that a form of molecular weight approx. 80 000 constitutes the "fundamental unit" of insect cholinesterase.
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PMID:Acetylcholinesterase from the house-fly head. Molecular properties of soluble forms. 95 30

In Turkey, the mosquito Anopheles sacharovi has been under field selection pressure sequentially with DDT, dieldrin, malathion and pirimiphosmethyl over a period of 30 years for the purpose of malaria control. In 1984, the field population of An.sacharovi in the malarious Cukurova plain of Adana Province contained an altered acetylcholinesterase-based resistance gene giving broad spectrum resistance against organophosphorus and carbamate insecticides. The cross-resistance spectrum from this mechanism conferred resistance to malathion but not to the organophosphorus insecticide pirimiphos-methyl. Over the 6 years that pirimiphos-methyl has been applied for malaria vector control in this area, the frequency of the altered acetylcholinesterase resistance gene has declined, although in 1989 and 1990 it was still present at measurable frequencies in An.sacharovi from Cukurova. In addition to the acetylcholinesterase resistance mechanism there is evidence of an increased level of glutathione S-transferase in some of the An.sacharovi populations tested. This is known to be correlated with DDT resistance in other anophelines. In Turkish An.sacharovi, DDT resistance and elevated glutathione S-transferase occur in the same populations at similar frequencies. The continued prevalence of resistance to DDT and dieldrin, long after the 1971 cessation of DDT spraying for malaria control in Turkey, suggests that the DDT resistance gene has insufficient reduced fitness associated with it to have been lost from the field population during the past two decades. The implications of the slow decline in resistance gene frequencies in this field population are discussed in relation to mathematical models for managing resistance.
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PMID:Insecticide resistance gene frequencies in Anopheles sacharovi populations of the Cukurova plain, Adana Province, Turkey. 146 99

A colony of azamethiphos-resistant house flies, Musca domestica (L.), was obtained from Denmark and further selected in the laboratory with azamethiphos for four generations. LD50s for various insecticides were determined and compared with those of a susceptible house fly strain. The selected flies showed cross-resistance to all insecticides evaluated. The flies were highly resistant to most organophosphorus, carbamate, and chlorinated hydrocarbon insecticides except prothiophos, p,p'-DDT, and the pyrethroids. We conclude that the main mechanisms responsible for resistance are presumed to be factors other than acetylcholinesterase sensitivity and nerve sensitivity due to knockdown resistance.
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PMID:Studies on the resistance to various insecticides of a house fly strain (Diptera: Muscidae) selected with azamethiphos. 178 17

The target enzymes, acetylcholinesterase (for phosphamidon and carbaryl) and Mg2+ ATPase (for DDT and fenvalerate) have been assayed during exposure and reclamation of these insecticides in M. monoceros. Toxicity of these insecticides are in the order: fenvalerate greater than DDT greater than carbaryl greater than phosphamidon. Reclamation studies show that fenvalerate is rapidly degradable while DDT is slowly degradable. It is suggested that pyrethroid, organophosphate and carbamate insecticides may be preferred over organochlorine compounds in farm operations.
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PMID:Inhibition and recovery of selected target enzyme activities in tissues of penaeid prawn, Metapenaeus monoceros (Fabricius), exposed to different insecticides. 183 18

Genotoxicity of eight topically applied compounds was determined using the bone marrow micronucleus (MN) test and hair follicle nuclear aberration (NA) assay in CD1 mice. Twenty-four hours after a single treatment, cyclophosphamide (CY), applied at doses corresponding to 1/4, 1/8, 1/16, and 1/32 of the published dermal LD50, and N-methyl-N-nitrosourea (MNU), applied at 1/4, 1/8, and 1/16 of the published dermal LD50, were found to increase the incidence of NA in a dose-dependent manner. The frequency of MN was significantly increased only at the highest dose of CY. Using the same protocol, six pesticides applied in dimethyl sulfoxide (DMSO) at doses of 1/8, 1/16, and 1/32 of the dermal LD50 were investigated. Aminocarb and chlordane induced a dose-dependent increase in the frequency of NA, while there was an observed increase in NA incidence at only the highest doses of dichlorvos (DDVP), 4,4'-DDT (DDT), and 2,4-dichlorophenoxyacetic acid (2,4-D). No effect was observed with fenitrothion on nuclear aberrations in hair follicles. Except for the highest dose of chlordane, none of the pesticides tested positive in the bone marrow micronucleus test. Serum cholinesterase levels were reduced to 70 +/- 4.7% of the DMSO control level with DDVP, 57 +/- 8.2% with aminocarb, and 60.3 +/- 4.8% with fenitrothion, indicating some systemic activity with these topically applied agents. The data suggest that aminocarb, chlordane, DDVP, DDT, and 2,4-D are genotoxic as determined by the NA assay and that this assay may be more useful in detecting topically applied genotoxic agents than the more often used bone marrow micronucleus test.
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PMID:Comparison of the activity of topically applied pesticides and the herbicide 2,4-D in two short-term in vivo assays of genotoxicity in the mouse. 208 12

Results of health survey and biological monitoring in pesticide formulators exposed to a combination of pesticides, an organophosphorus (OP) insecticide (phorate) and a persistent chlorinated insecticide (technical hexachlorocyclohexane; HCH; BHC) are reported. Exposure of 160 workers to a combination of pesticides (malathion, parathion, DDT and HCH) resulted in 73% of the workers showing toxic signs and symptoms. Formulators showed marked inhibition of whole blood, plasma and red blood cell cholinesterase (ChE) activity and slightly higher concentrations of DDT and HCH in serum. An interesting observation was that over 25% of the formulators showed ECG aberrations. The ECG changes were not related to whole blood ChE activity. Exposure to the chlorinated insecticide HCH in 19 workers engaged in the manufacture of technical HCH resulted in toxic signs and symptoms in over 90% of the subjects. The HCH concentrations in serum showed a ten-fold increase. Changes in the liver enzymes ornithine carbamyl transferase (OCT), gamma-glutamyl transpeptidase (GGTP), leucine aminopeptidase (LAP) and in immunoglobulin M(IgM) showed possible effects on liver and humoral immunity. ECG monitoring showed evidence of cardiac effects. Exposure of 40 formulators to a highly toxic OP insecticide (phorate) showed that over 60% of the workers suffered from toxic effects in spite of using a complete set of protective clothing. A marked and progressive inhibition in whole blood and plasma ChE activity was found during the two weeks of exposure to phorate. An appreciable recovery in ChE activity was observed 10 days after cessation of exposure. These surveys have established the need to practice and develop biological monitoring techniques to assess exposure and predict health risks in workers occupationally exposed to pesticides.
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PMID:Health surveillance and biological monitoring of pesticide formulators in India. 243 Mar 50

Two field studies to assess the health implications for farmers applying two different formulations containing organophosphorus (OP) pesticides to cotton by hand-held ULV are described. The first study, carried out in the Ivory Coast, involved the application of an endrin/DDT/methylparathion (MEP) formulation in an aromatic hydrocarbon solvent. The second study took place in Indonesia with a 20% monocrotophos formulation in a mixture of a glycol and a glycol ether. Both studies were carried out under actual field conditions. The purpose of the studies was to get a good assessment of the health hazards of the particular formulation, used under the specific circumstances and agronomic requirements of the area of application and taking into account all local, climatic and cultural conditions that could be of possible influence. The results showed that in both studies skin exposures took place during application and especially during handling, filling and cleaning, and that inhalation of spray mist was negligible. Absorption was confirmed by the presence in urine of metabolites of endrin and methylparathion in the Ivory Coast study, and of dimethyl phosphate in the Indonesia study. No clinical signs or symptoms of intoxication were discovered in either study, nor were inhibitions of cholinesterase (ChE) activity of health significance established under the conditions of the studies. In addition, various practical aspects such as choice of apparatus, of formulation, the application procedures etc. are discussed.
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PMID:Field studies on health effects from the application of two organophosphorus insecticide formulations by hand-held ULV to cotton. 302 32

This article reviews the biological indicators available for monitoring human neurotoxicity by exogenous chemicals with reference to the phases in which the neurotoxic process takes place, namely delivery, receptor-linkage, and toxicodynamic phase. Among the delivery phase tests, indicators are available for metals (lead, mercury) and some organic substances (CS2, n-hexane, DDT, etc.), but a correlation between neurotoxic effects and these indices is rather loose or not yet proved. The receptor-phase tests comprise well known enzymes, such as cholinesterase, less known but promising indicators, such as neuropathy target esterase (NTE), and new tools under study, such as acrylamide-hemoglobin adducts or 2,5-hexanedione-protein adducts. The toxicodynamic phase tests, which mainly consist of measuring substances released from the nervous system, have provided so far rather poor results, but more specific techniques of measurement (monoclonal antibodies) could offer new possibilities in the future.
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PMID:Biological indicators of neurotoxicity in central and peripheral toxic neuropathies. 307 8


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