Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 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

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