Please use this identifier to cite or link to this item:
https://hdl.handle.net/10316/7857
DC Field | Value | Language |
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dc.contributor.author | Gonçalves, Paula P. | - |
dc.contributor.author | Meireles, Sandra M. | - |
dc.contributor.author | Neves, Paulo | - |
dc.contributor.author | Vale, M. Graça P. | - |
dc.date.accessioned | 2009-02-17T10:36:36Z | - |
dc.date.available | 2009-02-17T10:36:36Z | - |
dc.date.issued | 2001 | en_US |
dc.identifier.citation | Neurochemical Research. 26:1 (2001) 75-81 | en_US |
dc.identifier.uri | https://hdl.handle.net/10316/7857 | - |
dc.description.abstract | The effect of Ca2+ on the uptake of neurotransmitters by synaptic vesicles was investigated in a synaptic vesicle enriched fraction isolated from sheep brain cortex. We observed that dopamine uptake, which is driven at expenses of the proton concentration gradient generated across the membrane by the H+-ATPase activity, is strongly inhibited (70%) by 500 µM Ca2+. Conversely, glutamate uptake, which essentially requires the electrical potential in the presence of low Cl- concentrations, is not affected by Ca2+, even when the proton concentration gradient greatly contributes for the proton electrochemical gradient. These observations were checked by adding Ca2+ to dopamine or glutamate loaded vesicles, which promoted dopamine release, whereas glutamate remained inside the vesicles. Furthermore, similar effects were obtained by adding 150 µM Zn2+ that, like Ca2+, dissipates the proton concentration gradient by exchanging with H+. With respect to ?-aminobutyric acid transport, which utilizes either the proton concentration gradient or the electrical potential as energy sources, we observed that Ca2+ or Zn2+ do not induce great alterations in the ?-aminobutyric acid accumulation by synaptic vesicles. These results clarify the nature of the energy source for accumulation of main neurotransmitters and suggest that stressing concentrations of Ca2+ or Zn2+ inhibit the proton concentration gradient-dependent neurotransmitter accumulation by inducing H+ pump uncoupling rather than by interacting with the neurotransmitter transporter molecules. | en_US |
dc.language.iso | eng | eng |
dc.rights | openAccess | eng |
dc.title | Ca2+ Sensitivity of Synaptic Vesicle Dopamine, ?-Aminobutyric Acid, and Glutamate Transport Systems | en_US |
dc.type | article | en_US |
dc.identifier.doi | 10.1023/A:1007684716964 | en_US |
item.fulltext | Com Texto completo | - |
item.grantfulltext | open | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.openairetype | article | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
Appears in Collections: | FCTUC Ciências da Vida - Artigos em Revistas Internacionais |
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