Choline and acetylcholine

Flentge, F, Venema, K, Koch, T and Korf, J (1997) An enz5mie-reactor for electrochemical monitoring of choline and acetylcholine. Applications in high-performance liquid chromatography, brain tissue, microdialysis and cerebral fluid. Annal. Biochem. 204 305-311. 

M. Bernabai, C. Cremisini, M. Mascini, and G. Palleschi, Determination of organophosphorus and car-bamic pesticides with a choline and acetylcholine electrochemical biosensor. Anal. Lett. 24, 1317-1331 (1991). 

Wang, X.-F., et ah, Signat-on electrochemiluminescence biosensors based on CdS-carbon nanotube nanocomposite for the sensitive detection of choline and acetylcholine. Advanced Functional Materials, 2009.19(9) p. 1444-1450. 

Tsai T-H. 2000. Separation methods used in the determination of choline and acetylcholine. J Chromatogr B 747 111. 

Dunphy R, Burinsky DJ. 2003. Detection of choline and acetylcholine in a pharmaceutical preparation using high-performance liquid chromatography/electrospray ionization mass spectrometry. J Pharm Biomed Anal 31 901. 

Kramer MS, Cutler NR, Ballenger JC, et al A placebo-controUed trial of L-365,260, a CCKB antagonist, in panic disorder. Biol Psychiatry 37 462-466, 1995 Krauss GL, Fisher RS Cerebellar and thalamic stimulation for epilepsy, in Electrical and Magnetic Stimulation of the Brain and Spinal Cord. Edited by Devinsky O, Beric A. New York, Raven, 1993, pp 231-245 Krell RD, Goldberg AM Effect of acute and chronic administration of lithium on steady-state levels of mouse brain choline and acetylcholine. Biochem Pharmacol 22 3289-3291, 1973... 

Quarternization of tertiary amines causes jl and y effects which overlap with the shieldings induced by the positively charged nitrogen, as shown for some tetraalkylam-monium salts in Table 4.42 [339], Tetraalkylammonium ions display triplet splittings of 4 Hz due to 13C—14N coupling (/i[Pg.238]

The recent developments in the determination of acetylcholine and choline, the advantages and the disadvantages of a variety of analytical methods used in the analysis, were reviewed and discussed by Maruyama et al. [7]. Hanin published an overview for the methods used for the analysis and measurement of acetylcholine [8], Shimada et al. presented a review, including the applications of some reactors in the analysis of choline and acetylcholine. The immobilized enzyme reactors were used for detection systems in high performance liquid chromatography [9],... 

Tsai reviewed the separation methods used in the determination of choline and acetylcholine [10]. This review surveyed the array of analytical techniques that have been adopted for the measurement of acetylcholine or its main precursor/metabolite (choline), ranging from simple (bioassay, radio enzymatic assay, gas chromatography-flame ionization detection, gas chromatography-mass spectrometry, high... 

Enzymes Enzymes immobilized in a polymer solution. Acetylcholine and choline are determined at the pM level with a precision of 3.5-7%. Detection limits were 0.1 and 1 pM of Ch and ACh, respectively. Calibration graphs were rectilinear for 0.1-100 and 1-100 pM of choline and acetylcholine. Storage stability of the sensing element is satisfactory. Response time was 3-10 min. [80]... 

Acetylcholineesterase and choline oxidase The detector consisted of two Pt electrodes (6 mm x 3 mm) sandwiched between Perspex sheets and separated by a 1 mm thick sheet of silicone rubber, and the carrier stream (0.5 mL/min) was 0.1 M phosphate buffer (pH 8.2). AChE and ChO were immobilized by glutraldehyde cross-linking to controlled-pore glass and packed into columns (3 cm x 2.5 mm) that were operated at 25° C. Rectilinear calibration graphs for 10-100 pM choline and acetylcholine were obtained. [104]... 

A kinetic-fluorimetric method for the determination of choline and acetylcholine by oxidation with cerium (IV) was reported by Lunar et al. [47]. To sample solutions containing 0.017-1.OmM choline and/or acetylcholine were successively added 6M H2S04 (5mL) and 7.1 mM Ce(IV) solution (0.35 mL), the mixture diluted to 10 mL with water, and the solution heated to 80° C for 2 min. A portion of the solution was transferred to a cell maintained at 20 0.1°C, and after 1 min the Ce(III) fluorescence intensity was measured at 360 nm (excitation at 260 nm) as a function of time. 

Mascini and Guilbault presented a review covering the methods used for immobilization of the enzymes, enzyme electrodes, and sensors for choline and acetylcholine [62]. A number of reports have appeared in the literature [21, 22, 63-124] describing biosensors used for the detection and the analysis of acetylcholine. The important characteristics of some of these reports are summarized in Table 1. 

Maruyama et al. reported the use of a simple pyrolysis gas chromatographic method for the determination of choline and acetylcholine in brain tissue [136]. Schmidt and Speth reported a simultaneous analysis of choline and acetylcholine levels in rat brain tissue by a pyrolysis gas chromatographic method [137], Kosh et al. reported an improved gas chromatographic method for the analysis of acetylcholine and choline in rat brain tissue [138], Mikes et al. used a syringe micro-pyrolyzer for the gas chromatographic determination of acetylcholine, choline and other quaternary ammonium salts [139],... 

Gilberstadt and Russell determined picomolar quantities of acetylcholine and choline in a physiological salt solution [140]. Carbon-14 labeled choline and acetylcholine standards in Krebs-Ringer solution were subject to chromatography on columns (12 mm x 8 mm) packed with Bio-Sil A (200 400 mesh), and it was found that 95 98% of choline and acetylcholine were retained. Of the bound choline, 84-97% was eluted in 1.5mL of 0.075 M HC1, and then 95 98% of the bound acetylcholine was eluted in 1.5 mL of 0.03 M HC1 in 10% butan-2-one. 

The application of immobilized enzyme reactors in HPLC was reported by Shimada et al. [9] and by Shi and Du [143]. The latter authors cited the reactors used for the determination of choline and acetylcholine in their review. 

Stein reported the separation of choline and acetylcholine by a cation-exchange chromatographic method [198]. Four columns were compared by Salamoun et al. for the separation of choline and acetylcholine by cation exchange liquid chromatography [178]. The mobile phase used was... 

Choline and acetylcholine were extracted from mouse brain homogenates, in the presence of 2H9-choline and 2H4-acetylcholine, and the extract was analyzed directly by HPLC-MS on a column (15 cm x 4.6 mm) of Ultrasphere-I.P. ODS. The mobile phase was 0.1 M ammonium acetate-2 mM pyridine containing octanesulfonic acid (50mg/L, pH 5), and was eluted at a flow rate of 1.25mL/min. The column was coupled to a quadrupole mass spectrometer by the thermospray interface, and selected ions were monitored at mjz 104, 113, 146 and 150 for choline, [2H9] choline, acetylcholine and [2H4] acetylcholine, respectively. 

Eckernas and Aquilonius described a simple radioenzymatic procedure for the determination of choline and acetylcholine in brain regions of rats sacrificed by microwave irradiation [215]. The methods are based on acetylation (in phosphate buffer) of free choline with [14C]-acetylcholine using purified choline acetyltransferase. After ion-pair extraction of [14C]-acetylcholine with tertiary phenyl borate contained in toluene-based scintillation cocktail, the radioactivity was measured. 

Saelens et al. measured choline, acetylcholine, and their metabolites by combined enzymatic and radiometric techniques [219]. Choline and acetylcholine were isolated from tissue extracts by a low voltage... 

Stavinoha, W. B. and Weintraub, S. T. (1974) Estimation of choline and acetylcholine in tissue by pyrolysis gas chromatography, Anal. Chem. 46, 757-760. 

Moreover, the strong binding displayed by the tetramethyl ammonium cation led to consider that cryptophanes of the size of 38 might be suitable receptors for substrates of structure Me3N + — R in which R would be an aliphatic chain or a functionalized chain such as that of choline and acetylcholine. In fact, it is found that, in (CDC12)2, the binding constant drops rapidly as the length of an aliphatic... 

Enzyme electrodes for choline and acetylcholine (300, 301) and for the analysis of choline-containing phospholipids (303, 304) is obtained by immobilizing choline oxidase or choline oxidase and acetylcholinesterase on membranes at the tip of platinum electrodes. The formation of hydrogen peroxide is monitored ... 

Figure 14.3. Biosynthesis of choline, and acetylcholine. Relative molecnlar masses (Mr) choline, 104.2 (chloride, 139.6) and acetylcholine, 146.3 (chloride, 181.7). CoASH, free coenzyme A.

The reductive methylation of amines with formaldehyde in the presence of formic acid. See Lindeke, B., Anderson, B., and Jenden, D.J., Specific deuteromethylation by the Eschweiler-Clark reaction. Synthesis of differently labelled variants of trimethylamine and their use of the preparation of labelled choline and acetylcholine, Biomed. Mass Spectrom. 3, 257-259, 1976 Boldavalli, E, Bruno, O., Mariani, E. et al.. Esters of A-methyl-iV-(2-hydroxyethyl or... 

Unesterified thiocholine and selenocholine display a relatively high degree of acetylcho-line-like potency and activity compared with their acetate esters, in contrast to the dramatic potency difference between choline and acetylcholine. The biological effects of these unesterified thiols and selenols have been suggested to be due to their oxidation to disulfide and diselenide derivatives (77). The amide congener (26) of acetylcholine has little or no... 

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