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Journal ArticleDOI

Choline: high-affinity uptake by rat brain synaptosomes.

Henry I. Yamamura, +1 more
- 10 Nov 1972 - 
- Vol. 178, Iss: 4061, pp 626-628
TLDR
The high-affinity choline uptake appears to represent selective choline accumulation by cholinergic neurons, and is associated with considerable formation of acetylcholine.
Abstract
Synaptosomes from rat brain accumulate choline by two kinetically distinct processes, a high-affinity uptake system [Michaelis constant (K(m)) = 1 x 10(-6)M], and a low-affinity system (K(m) = 9 x 10(-5)M). The high-affinity uptake system requires sodium, and is associated with considerable formation of acetylcholine. The low-affinity uptake system is less dependent on sodium, and does not appear to be associated with a marked degree of acetylcholine formation. The high-affinity choline uptake appears to represent selective choline accumulation by cholinergic neurons.

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Citations
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Journal ArticleDOI

Muscarinic Cholinergic Binding in Rat Brain

TL;DR: Binding sites with high affinity and specificity for [(3)H]quinuclidinyl benzilate (QNB) are present in homogenates of rat brain and the characteristics of the binding sites resemble those of muscarinic cholinergic receptors.
Journal ArticleDOI

High affinity transport of choline into synaptosomes of rat brain.

TL;DR: A variety of evidence suggests that the high affinity transport represents a selective accumulation of choline by cholinergic neurons, while the low affinity uptake system has some less specific function.
Journal ArticleDOI

Choline: selective accumulation by central cholinergic neurons.

TL;DR: The results suggest that when hippocampal synaptosomes are incubated in the presence of choline, at concentrations of 10 μm m or lower, then cholinergic nerve endings are responsible for the bulk of the choline accumulated by the tissue.
Journal ArticleDOI

Sodium-dependent, high affinity choline uptake

TL;DR: This review will focus on choline transport into cholinergic neurons, especially by means of the sodium-dependent, high affinity choline uptake system (SDHACU) which appears to be involved in ACh synthesis and its regulation.
References
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Journal ArticleDOI

The Determination of Enzyme Dissociation Constants

TL;DR: On the basis of the assumed theory the rate of the observed reaction is directly proportional to the concentration of the enzyme-substrate compound, where (E:l = (ES).
Journal ArticleDOI

Regional studies of catecholamines in the rat brain. I. The disposition of [3H]norepinephrine, [3H]dopamine and [3H]dopa in various regions of the brain.

TL;DR: It is revealed that norepinephrine and dopamine are specifically localized in complex systems of neurons in the brain, a finding which lends support to the hypothesis that both amines may be neurotransmitters in the central nervous system.
Journal ArticleDOI

Acetylcholine metabolism of a sympathetic ganglion

TL;DR: The synthesis, storage, and release of acetylcholine were studied in perfused and intact superior cervical ganglia of cats and determined by bio-assay in ganglion extracts and in the venous ganglia.
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