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

Eosin derivatives that bind primarily to lipid or protein sites in erythrocyte membranes were studied in solution and as sensitizers of erythrocyte membranes. In 50% ethanol-water mixtures eosin maleimide (EYMA) and 5-N-hexadecanoyl amino eosin (E16) had nearly identical absorption spectra. Higher ethanol concentrations did not change peak absorbances. In the presence of neutral detergent both sensitizers had equivalent absorbance at all ethanol concentrations. In water, EYMA was more effective than E16 at bleaching RNO, probably because of E16 aggregation into micelles, while in ethanol-water mixtures E16 was slightly more effective at bleaching DPBF, indicating equivalent singlet oxygen generation when the sensitizers are in monomeric form. In water with neutral detergent, azide in the 20 microM range inhibited the majority of RNO bleaching with both sensitizers; in 50% ethanol-water mixtures azide at 1 mM showed a 50% inhibition of DPBF bleaching with both sensitizers. Iodide in the 30 mM range reduced DPBF bleaching by 50% in 50% ethanol-water mixtures. When matched for amount loaded in erythrocyte membranes these sensitizers were about equally effective at sensitizing induction of cation permeability, assayed as rate of delayed photohemolysis, while E16 was slightly more effective at sensitizing loss of cholinesterase (AchE) activity. The relation of lysis rate to load was somewhat steeper for E16 than EYMA. For both sensitizers lysis rate increased at about the 1.5 power of light dose. Deoxygenation of the reaction media with argon totally blocked detectable photomodification. Ghost membranes made from sensitizer-treated cells were effective generators of singlet oxygen, assayed by RNO bleaching. However, when mixtures of EYMA-treated and untreated cells were illuminated together, only the EYMA-treated cells showed evidence of photomodification. Azide at 5 mM slowed the initial rate of AchE loss by about 75% with E16 and EYMA. Azide partially slowed photohemolysis. Azide decreased RNO bleaching by sensitizer-treated ghosts as it did in water with detergent micelles. A deuterium oxide solvent increased photohemolysis rate with E16 by 41%, but did not increase photohemolysis rate with EYMA. Deuterium oxide had a positive, but statistically insignificant effect on loss of AchE with both sensitizers. Deuterium oxide following illumination slowed lysis sensitized by both sensitizers more than 50%. Iodide exerted a modest inhibition of photohemolysis and loss of AchE sensitized by E16, but had virtually no influence on sensitization by EYMA. The results in solution indicate that EYMA and E16 have nearly identical photochemical properties when in monome
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PMID:Photooxidation of cell membranes using eosin derivatives that locate in lipid or protein to study the role of diffusible intermediates. 247 36

To study the retinal changes in occupationally exposed pesticide workers, 79 subjects exposed to an organophosphate, fenthion, and 18 exposed to an organochlorine pesticide DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane], were subjected to a detailed study, including history taking, physical examination and ophthalmic evaluation. Fluorescein angiography was performed in selected cases. Serum cholinesterase level in 22 workers and serum DDT residue in 17 workers of the respective groups were also estimated. Fifteen workers (19%), who were exposed to fenthion had macular changes (P less than 0.01). The macular lesions were characterized by perifoveal irregularity of pigmentation and areas of hypopigmentation of 1/8-1/3 disc diameter. Mean age of the subjects having macular involvement was 30.6 years and mean duration of exposure 7.9 years. The symptoms reported by them were diminution of vision (8), dislike for bright light, flash of light, black dots in front of the eyes (2 each) and visual blurring (1). Paracentral scotoma and constriction of peripheral field were present in three workers each. Fluorescein angiography suggested pigment epithelium defect. Other causes of macular involvement in these workers were excluded; a possible role of pesticides in the genesis of these macular changes is suggested.
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PMID:Some observations on the macula of pesticide workers. 400 78

Alzheimer's disease (AD) is associated with a reduction in cholinergic activity as a result of specific neuronal loss. Current potential treatments for the disease include both cholinomimetic drugs and anticholinesterase inhibitors. One of the drugs approved by the FDA is tacrine (9-amine-1,2,3,4 tetrahydroacridine; THA), a strong acetylcholinesterase (AChE) inhibitor. We have studied the effects of tacrine on glial and neuronal cells in culture assessing cell survival and viability and morphology. Lactate dehydrogenase (LDH) activity and methylthiazol-diphenyl-tetrazolium (MTT) reduction were used as toxicity indicators. We found that tacrine toxicity on rat B12 glial cells and mouse Neuro 2A cells was strongly dependent on its concentration (up to 500 microM) and time of exposure. The toxic effect was not prevented by serum factors nor by bovine serum albumin. Fluorescein-conjugated phalloidin was used to examine the arrangement of actin filaments at substrate adhesion regions and cell-cell contacts. Primary events following exposure to tacrine included changes in cell morphology, disappearance of actin filament bundles, and disruption of focal adhesion contacts. At concentrations between 10 and 50 microM, tacrine induced neurite outgrowth in Neuro 2A cells, an effect that was not observed in B12 cells, suggesting that certain tacrine effects could be specific for neuronal cells. Although similar trends of response were observed for both cell types, some differences between undifferentiated and differentiated cells were apparent.
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PMID:Responses induced by tacrine in neuronal and non-neuronal cell lines. 958 88

Acetylcholinesterase (AChE) localization in the human thymus has been studied by biochemical and morphological methods during development and aging. The occurrence, the amount and the distribution of acetylcholinesterase and the changes with age were examined in 24 human thymuses. The whole human thymus was removed during autopsies in males of the following age-groups: prenatal of six months, new-born, infant, young, adult and elderly. The thymuses were weighed, measured and dissected: the microanatomical details were stained with Eosin-orange, nervous structures were identified by means of Bodian's method. Protein content was determined with biochemical methods. Histoenzymatical and biochemical demonstration of acetylcholinesterase was performed. The morphological results obtained were submitted to quantitative image analysis. Our results show that the thymic microenvironment changes with age; moreover, an increase of acetylcholinesterase-positive structures can be observed with age. Biochemical results are in agreement with morphological results and both are confirmed by the outcome of quantitative analysis of images. Acetylcholinesterase activity in human thymus may play a key role in thymic functions.
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PMID:Quantification of acetylcholinesterase-positive structures in human thymus during development and aging. 1056 61

The nature of the immune response following ocular immunization with a protein and a polysaccharide and the effects such immunization have on the activities of cholinergic enzymes in the lacrimal glands of BALB/c mice were examined. Lacrimal glands are highly innervated by sympathetic and parasympathetic nerve fibres and are involved in mucosal immunity and therefore are excellent sites to study neuro-immune interactions. In this report, a T-lymphocyte-dependent protein antigen, keyhole limpet haemocyanin (KLH) and a T-lymphocyte-independent polysaccharide antigen, dextran (DEX) were administered topically to the eyes or intraperitoneally injected. Both routes of immunization produced a strong serum antibody response when KLH was the antigen. DEX, however, evoked a serum antibody response only after intraperitoneal administration. Eosin-haematoxylin staining indicated no histological abnormality or inflammatory changes in any immunized lacrimal glands, but immuno-staining revealed that only in the KLH-treated tissues were IgG-producing plasma cells discernible. Furthermore, KLH-specific antibody was also detectable using an immuno-blot assay in lacrimal glands. Polymerase chain reaction analysis with cytokine-specific primers revealed induction of interleukin-4 (lL-4) in KLH-treated lacrimal glands, but not in DEX or unimmunized tissues. Thus, the nature of the antigen seems important in the induction of the immune response in lacrimal glands. To delineate the effects that immunogenic differences might have on the activities of the cholinergic enzymes, choline acetyl-transferase (ChAT) and acetylcholinesterase (AChE) were assayed using radiolabelled substrates and measuring labelled products. Both ChAT and AChE activities were influenced following KLH immunization, while DEX had only transient effects on ChAT. This is possibly due to the fact that KLH, a protein antigen, is the effective inducer of the specific immune response in the lacrimal gland, while DEX is not. Experimental Physiology (2001) 86.2, 169-176.
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PMID:Effects of T-lymphocyte-dependent and -independent immunity on cholinergic enzyme activity in mouse lacrimal gland. 1142 31

Low doses of the acetylcholinesterase-inhibiting carbamate nematicides disrupt chemoreception in plant-parasitic nematodes. Fluorescein isothiocyanate (FITC)/dextran conjugates up to 12 kDa are taken up from the external medium by certain chemosensory neurons in Caenorhabditis elegans. Similar chemoreceptive neurons of the non-feeding infective stage of Heterodera glycines (soybean cyst nematode) fill with FITC and the nuclei of their cell bodies selectively stain with bisbenzimide. The widely used nematicide aldicarb disrupts the chemoreceptive response of H. glycines with 50% inhibition at very low concentrations (ca 1 pM), some 10(-6)-fold lower than required to affect locomotion. Similarly, the anthelmintic levamisole had this effect at 1 nM. Peptides selected as mimetics of aldicarb and levamisole also disrupt chemoreception in H. glycines and Globodera pallida at 10(-3)-fold or lower concentration than required to inhibit locomotion. We propose an uptake pathway for aldicarb, levamisole, peptide mimetics and other soluble molecules by retrograde transport along dendrites of chemoreceptive neurons to the cell bodies and synapses where they act. This may prove to be a general mechanism for the low-dose effects of some nematicides and anthelmintics.
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PMID:Neuronal uptake of pesticides disrupts chemosensory cells of nematodes. 1255 75

In this study, the lateral geniculate bodies (LGB) of rats, bats and pangolins were compared using histological and quantitative histochemical parameters to observe possible modifications that enable these mammals to cope with their habitation particularly with respect to their diet. The study was conducted using ten adult Wistar rats, ten fruit bats and eight pangolins comprising of both sexes. After being sacrificed by cervical dislocation, their skulls were opened using bone forceps to expose the brains. The lateral geniculate bodies were excised from each brain tissue, homogenized and homogenate studied spectrophotometrically for the activities of lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G-6-PDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and acetylcholinesterase (AChE). The LGB tissue samples meant for histological studies were fixed in 10% formol calcium and processed for paraffin wax embedding. Serial sections of 3?m thickness were stained with Hematoxylin and Eosin (H & E) and Cresyl fast violet (CFV) stains. The stained tissues were studied under the light microscope. Application of one-way ANOVA statistical method showed that there were significant differences (p<0.05) in the activities of LDH, G-6-PDH, ACP, ALP and AChE of the LGB of the three mammals as revealed in the quantitative histochemistry of these enzymes and markers. Histological observations revealed no observable differences in the relative distribution of neurons and their supporting glial cells within the LGB of the three mammalian species. The comparison of the differences observed in the histological and the quantitative histochemical activities in these mammalian species revealed a variation in the visual perception and their individual peculiarities in relation to their mode and pattern of living.
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PMID:A comparative study of the lateral geniculate body of rat (Rattus norvegicus), bat (Eidolon helvum) and pangolin (Manis tricuspis). 2298 Mar 48

We exposed the Japanese quail (Coturnix coturnix japonica) to the organophosphate methamidophos using acute oral test. Mortality and sub-lethal effects were recorded in accordance to internationally accepted protocols. In addition cholinesterases were biochemically estimated in tissues of the quail: brain, liver and plasma. Furthermore, brain, liver and duodenum cryostat sections were processed for cholinesterase histochemistry using various substrates and inhibitors. Mortalities occurred mainly in the first 1-2h following application. Sub-lethal effects, such as ataxia, ruffled feathers, tremor, salivation and reduced or no reaction to external stimuli were observed. Biochemical analysis in the brain, liver and plasma indicates a strong cholinesterase dependent inhibition with respect to mortality and sub-lethal effects of the quail. The histochemical staining also indicated a strong cholinesterase inhibition in the organs examined and the analysis of the stained sections allowed for an estimation and interpretation of the intoxication effects of methamidophos, in combination with tissue morphology visible by Haematoxylin and Eosin staining. We conclude that the use of biochemistry and histochemistry for the biomarker cholinesterase, may constitute a significantly novel approach for understanding the results obtained by the acute oral test employed in order to assess the effects of methamidophos and other chemicals known to inhibit this very important nervous system enzyme.
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PMID:Japanese quail acute exposure to methamidophos: experimental design, lethal, sub-lethal effects and cholinesterase biochemical and histochemical expression. 2314 11