Acetylthiocholine

About: Acetylthiocholine is a research topic. Over the lifetime, 278 publications have been published within this topic receiving 29340 citations.

A histochemical method for localizing cholinesterase activity.

Abstract: SummaryA histochemical method is presented for localizing ChE activity by incubating tissue sections in a medium containing acetylthiocholine, copper glycinate and copper thiocholine. Results obtained with several tissues containing specific ChE are described and illustrated.

The histochemical identification of acetylcholinesterase in cholinergic, adrenergic and sensory neurons.

Abstract: A previously described histochemical method for the localization of specific or aeetylcholinesterase (AChE) and non-specific cholinesterase (ChE) has been modified to increase its specificity and sensitivity for studies of tissues of the cat, rabbit and rhesus monkey. The concentrations of B.W. 284C51, DFP or Nu 683, and eserine required for the selective complete inhibition of one or both types of enzyme were determined manometrically, using brain homogenates of each of the three species amid employing the specific substrates methacholine (MeCh) and butyrylcholine (BuCh), the histochemical substrates acetylthiocholine (AThCh) and butyrylthiocholine (BuThCh), and acetylcholine (ACh). Determinations were conducted both under optimal conditions for enzymatic activity, and in the presence of the same concentrations of Na 2 SO 4 and at the same pH as in the histoehemical incubation media. Acetylthiocholine and BuThCh were found to be hydrolyzed by additional enzymes which are resistant to the selective inhibitors of AChE and non-specific ChE in the brains of all three species. By the addition of the inhibitors, alone and in combination, to the incubation media, it was possible to ascertain the specificity of staining for AChE and non-specific ChE when the selective inhibitors are absent. Sensitivity was increased by increasing the period of incubation to two hours. As reported previously, high concentrations of AChE were localized in the cholinergic neurons of all three species. However, it was also found that lower, variable concentrations are present in all the adrenergic and sensory neurons examined. Non-specific ChE activity was found in the glial cells at all sites, and in the neurons and interstitial cells of Auerbach9s plexus. The inhibitor-resistant esterases were apparently of low activity in peripheral ganglia, and were confined largely to the glial cells. Implications of the present findings concerning the processes of transmission and conduction are discussed. On the basis of these results and those of other investigators, it is suggested that the terms cholinergic and adrenergic may refer to the predominant but not necessarily the exclusive transmitting agents of the respective nerve fibers.

Inhibition of the Acetycholine Esterase-Stimulated Growth of Au Nanoparticles: Nanotechnology-Based Sensing of Nerve Gases

Abstract: The acetylcholine esterase, AChE, mediated hydrolysis of acetylthiocholine (1) yields a reducing agent thiocholine (2) that stimulates the catalytic enlargement of Au NP seeds in the presence of AuCl(4)(-). The reductive enlargement of the Au NPs is controlled by the concentration of the substrate (1) and by the activity of the enzyme. The catalytic growth of the Au NPs is inhibited by 1,5-bis(4-allyldimethylammoniumphenyl)pentane-3-one dibromide (3) or by diethyl p-nitrophenyl phosphate (paraoxon; 4), thus enabling a colorimetric test for AChE inhibitors. The colorimetric assay was also developed on glass supports.

Microfluidic Assays of Acetylcholinesterase Inhibitors

Abstract: A microfabricated device for flow injection analysis and electrophoretic separation of acetylcholinesterase (AChE) inhibitors is described. Solutions of inhibitor, enzyme, substrate, and derivitizing agent were mixed within the channels of the microchip using computer-controlled electrokinetic transport. AChE-catalyzed hydrolysis of acetylthiocholine to thiocholine was measured in an on-chip reaction of thiocholine with coumarinylphenylmaleimide, and the resulting thioether was detected by laser-induced fluorescence. Inhibitors reduced the fluorescence signal and produced a negative peak diagnostic for the type of inhibition. A Gaussian peak was observed for competitive inhibitors, whereas a broad negative peak was observed for irreversible inhibitors. From a microchip assay for tacrine, an inhibition constant, Ki, of 1.5 ± 0.2 nM was derived, which compared well with a standard cuvette assay. A flow injection assay of two irreversible inhibitors, carbofuran and eserine, was performed. With a 5-min stoppe...