Zinc modulation of GABAA receptor-mediated chloride flux in rat hippocampal slices

Gordey, M.; Kang, Maeng-Hee; Olsen, Richard W.; Spigelman, Igor

doi:10.1016/0006-8993(95)00653-8

Cited by 7 publications

(4 citation statements)

References 48 publications

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“…Multiple receptors for albumin are currently under investigation (12, 34). Zinc has previously been shown to influence the receptor‐ligand interaction of adenosine (44), orosomucoid (45), human growth hormone (46), GABA (47–49), and NMDA (50). Under physiological circumstances, only about 1 in 40 albumin molecules carries a zinc atom.…”

Section: Discussionmentioning

confidence: 99%

Albumin Facilitates Zinc Acquisition by Endothelial Cells

Rowe

Bobilya

2000

Proc Soc Exp Biol Med

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Abstract. Albumin has long been observed to have a marked influence on the delivery of zinc to cells, but the mechanism of the interaction remains elusive. We examined whether albumin facilitates the acquisition of zinc by endothelial cells. Cultures of endothelial cells were used to analyze binding and acquisition of zinc and albumin to test this interaction. Our results indicate that albumin plays a role in facilitating the physiological delivery of zinc to endothelial cells. Albumin receptors that preferentially recognize albumin molecules carrying a zinc atom were demonstrated on the endothelial cell surface. Endocytosis is instrumental in albumin uptake, which was also consistently true of zinc uptake. Zinc and albumin were acquired by the cells in a 1:1 molar stoichiometry during the first 20 min of incubation in a medium with equimolar concentrations of zinc and albumin. The amount of albumin associated with the cells stabilized after 30 min, whereas the amount of zinc continued to increase. One possible explanation for this result is that a physiological route for zinc delivery into endothelial cells is by co‐transport with albumin via receptor‐mediated endocytosis.

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Section: Discussionmentioning

confidence: 99%

Albumin Facilitates Zinc Acquisition by Endothelial Cells

Rowe

Bobilya

2000

Proc Soc Exp Biol Med

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“…It has also been shown that zinc ions inhibit GABA responses mediated through GABA B receptors (Westbrook and Mayer, 1987;Xie and Smart, 1991;Gordey et al, 1995). The molecular layer of the DCN contains a high density of GABA B receptors , to which zinc may gain access from nearby granule cell endings.…”

Section: Vesicular Zinc Is Concentrated In Granule Cell Endings Of Thmentioning

confidence: 99%

“…Zinc could also slightly facilitate the activation of ␣-amino-3hydroxy-5-methyl-4-isoxazole acid (AMPA) receptors. Although zinc could also antagonize ␥-aminobutyric acid (GABA)-mediated inhibition (Westbrook and Mayer, 1987;Gordey et al, 1995), the bulk of the data strongly suggests an association between this cation and excitatory glutamatergic synapses. It would, therefore, be important to address whether zinc is localized in synaptic populations of the DCN.…”

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confidence: 99%

Chemical anatomy of excitatory endings in the dorsal cochlear nucleus of the rat: Differential synaptic distribution of aspartate aminotransferase, glutamate, and vesicular zinc

Rubio

Juı́z

1998

J. Comp. Neurol.

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In order to identify cytochemical traits relevant to understanding excitatory neurotransmission in brainstem auditory nuclei, we have analyzed in the dorsal cochlear nucleus the synaptic distribution of aspartate aminotransferase, glutamate, and vesicular zinc, three molecules probably involved in different steps of excitatory glutamatergic signaling. High levels of glutamate immunolabeling were found in three classes of synaptic endings in the dorsal cochlear nucleus, as determined by quantitation of immunogold labeling. The first type included auditory nerve endings, the second were granule cell endings in the molecular layer, and the third very large endings, better described as "mossy." This finding points to a neurotransmitter role for glutamate in at least three synaptic populations in the dorsal cochlear nucleus. The same three types of endings enriched in glutamate immunoreactivity also contained histochemically detectable levels of aspartate aminotransferase activity, suggesting that this enzyme may be involved in the synaptic handling of glutamate in excitatory endings in the dorsal cochlear nucleus. There was also extrasynaptic localization of the enzyme. Zinc ions were localized exclusively in granule cell endings, as determined by a Danscher-selenite method, suggesting that this ion is involved in the operation of granule cell synapses in the dorsal cochlear nucleus.

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“…These are the so-called zinc-enriched neurons (Frederickson, 1989;Frederickson and Moncrieff, 1994) which accumulate glutamate and zinc inside their synaptic vesicles (Martinez-Guijarro et al, 1991) and release it during synaptic transmission (Assaf and Chung, 1984;Howell et al, 1984). In the extracellular space, ionic zinc interacts with GABA and NMDA receptors, thus modulating the inhibitory as well as the excitatory synaptic effects (Gordey et al, 1995;Westbrook and Mayer, 1987). In spite of the high mobility of these ions and their strong interactions with an additional variety of proteins, it is possible to detect them by means of histocytochemical methods.…”

Section: Introductionmentioning

confidence: 99%

Cytochemical techniques for zinc and heavy metals localization in nerve cells

López‐García

Varea

Palop

et al. 2002

Microscopy Res & Technique

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Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to metallothioneins, loosely bound to some metalloproteins and nucleic acids, or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors, and transcription factors; thus, cells need accurate homeostasis of zinc ions. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartments ("vesicular zinc") which can be revealed using histochemical techniques. This article is a short report on the different direct-indirect experimental approaches for zinc and heavy metal detection in neurons. Substances giving a bright color or emitting fluorescence when in contact with divalent metal ions are currently used to detect them inside cells; their use leads to the so called "direct" methods. The fixation and precipitation of metal ions as insoluble salt precipitates, their maintenance along the histological process, and their demonstration after autometallographic development are essential steps for other methods, the so-called "indirect methods" (Timm and Danscher Neo-Timm methods).

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Zinc modulation of GABAA receptor-mediated chloride flux in rat hippocampal slices

Cited by 7 publications

References 48 publications

Albumin Facilitates Zinc Acquisition by Endothelial Cells

Albumin Facilitates Zinc Acquisition by Endothelial Cells

Chemical anatomy of excitatory endings in the dorsal cochlear nucleus of the rat: Differential synaptic distribution of aspartate aminotransferase, glutamate, and vesicular zinc

Cytochemical techniques for zinc and heavy metals localization in nerve cells

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