High-voltage electrophoresis of choline and its esters

Brooker, Sheila E.; Harkiss, K. J.

doi:10.1016/s0021-9673(01)84166-2

Cited by 11 publications

(4 citation statements)

References 5 publications

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“…Duplicate 10-pl samples were dissolved in protosol and counted in Liquifluortoluene scintillation fluid; the remainder was spun for 10 min at 3000 g in a Sorvall refrigerated centrifuge at 4°C. The supernatant was applied to Whatman 3 MM paper and electrophoresed 1 h a t 50 V/cm in 1.5 M-acetic acid-0.75 M-formic acid at p H 2 (Potter and Murphy, 1967;Brooker and Harkiss, 1974) using a Savant FP22b system with a constant voltage power source.…”

Section: Acetylcholine Assaymentioning

confidence: 99%

Ionic and Metabolic Requirements for High‐Affinity Choline Uptake and Acetylcholine Synthesis in Nerve Terminals at a Neuromuscular Junction

Beach

Vaca

Pilar

1980

Journal of Neurochemistry

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We have shown previously that in the chick ciliary nerve-iris muscle preparation Na' -dependent high-affinity choline uptake was confined to the nerve terminals. In this paper the sodium-dependent high-affinity choline uptake (SDHACU), which is coupled to acetylcholine (ACh) synthesis, was further characterized by measuring uptake of [:'H]choline and its conversion to [3H]ACh under a variety of ionic and metabolic perturbations. Mannitol equilibration with the extracellular space was found to occur in less than I min in this preparation. Na+-dependent choline (Ch+) uptake was shown to be linear for 16 min and to reach an equilibrium before Na+-independent Ch+ uptake, which continued to increase for 60 min. Elevated [K+], concentrations inhibited Ch+ uptake and ACh synthesis. Glycolytic and respiratory inhibitors also reduced both processes, as did ouabain and omission of [K+],. Incubation conditions that reduce transmitter release had no effect on inhibition by high [K+],. Reduction of SDHACU and sodium-dependent ACh synthesis by depolarization with high [K+], or by inhibition of Na, K-ATPase implies that the electrochemical gradients for Ch+ and Nat are important in providing a driving force for high-affinity Chi uptake. The inhibition by metabolic blockers suggests active transport, but the effects may be indirect, caused by reduced Na, K-ATPase activity and alterations in membrane potential. While most metabolic inhibitors exerted parallel effects on both Cht uptake and ACh synthesis, in some cases Ch' uptake was more strongly inhibited than ACh synthesis. This occurred in preparations incubated with high [K'],, and ouabain. Na+-dependent Chi uptake and ACh synthesis were found to be temperaturedependent with a Qlo (20-30") of 3.6 and 6.6, respectively, and a Qlo (30-40") of 1.3 and 1.0, respectively. Inhibition of acetylcholinesterase by paraoxon increases to 92% the proportion of the Ch+ taken up which is converted to ACh. ACh did not reduce Ch+ transport when present at 100 p~. Two transport systems for choline (Ch+) have been shown to exist in a variety of neural tissues. A sodium-dependent, high-affinityCh+ uptake has been found in synaptosome preparations (Yamamura and Snyder, 1973; Dowdall and Simon, 1973; Haga and Noda, 1973), minces from the guinea pig myenteric plexus (Pert and Snyder, 1974), isolated retina (Neal and Gilroy, 1975), neuronal cell cultures (Massarelli et al., 1974u,b), and rat superior cervical ganglia (Bowery and Neal, 1975). Since

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Section: Acetylcholine Assaymentioning

confidence: 99%

Ionic and Metabolic Requirements for High‐Affinity Choline Uptake and Acetylcholine Synthesis in Nerve Terminals at a Neuromuscular Junction

Beach

Vaca

Pilar

1980

Journal of Neurochemistry

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“…The eluant was a mixture of 90% w/v phenol and ethanol (50:50, v/v). Amino acids and betaine were localized, respectively, with 2% (w/v) ninhydrin in n ‐butanol and Dragendorf (Brooker and Harkiss 1974) reagents. Radiolabelled spots were detected and their radioactivity was determined by electronic autoradiography using the Packard Instantimager 2004.…”

Section: Methodsmentioning

confidence: 99%

Interaction between exogenous glycine betaine and the photorespiratory pathway in canola leaf discs

Sulpice

Gibon

Cornic

et al. 2002

Physiologia Plantarum

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The uptake and accumulation of exogenously supplied glycine betaine (GB) by canola (which never accumulates GB in response to stress) leaf discs has been found to induce damage to some of their structural and functional components. As a consequence some free amino acids were accumulated, particularly glutamine and glycine. Similar results were obtained with leaf discs of Arabidopsis thaliana i.e. another cruciferous plant that does not naturally produce significant amounts of GB. In contrast no changes in glutamine and glycine contents were observed in response to the GB treatment in leaf discs of spinach, a natural producer of GB. The change in glutamine content might be related to the senescing effects caused by the GB treatment. Glycine accumulation in response to GB has been more thoroughly studied with canola leaf discs. It only occurred under light conditions and was suppressed under non-photorespiratory conditions. The accumulation of

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“…Other methods that have been reported for the determination of choline, mostly with biological samples, include pyrolysis GC (Schmidt and Speth, 1975), high-voltage electrophoresis (Brooker and Harkiss, 1974), thin-layer chromatography using a Dragendorff reagent (McLean and Jewers, 1972), mass spectrometry (Johnston, et al, 1968), photometry following ion-pair extraction (Eksborg and Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221. 0021-8561/80/1428-0028$01.00/0 Persson, 1971), and radioisotopic measurement (Wang and Haubrich, 1975).…”

mentioning

confidence: 99%

Determination of choline in soybean meal by liquid chromatography with the ion-exchange membrane detector

Dorsey¹,

Hansen²,

Gilbert³

1980

J. Agric. Food Chem.

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High-voltage electrophoresis of choline and its esters

Cited by 11 publications

References 5 publications

Ionic and Metabolic Requirements for High‐Affinity Choline Uptake and Acetylcholine Synthesis in Nerve Terminals at a Neuromuscular Junction

Ionic and Metabolic Requirements for High‐Affinity Choline Uptake and Acetylcholine Synthesis in Nerve Terminals at a Neuromuscular Junction

Interaction between exogenous glycine betaine and the photorespiratory pathway in canola leaf discs

Determination of choline in soybean meal by liquid chromatography with the ion-exchange membrane detector

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