![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Vol. 56, Issue 5, 1047-1054, November 1999
Institute of Biochemical Pharmacology (C.P.) and Pharmacological
Institute (E.A.S.), University of Vienna, Vienna, Austria
The mechanism of release mediated by the human dopamine and
norepinephrine transporter (DAT and NET, respectively) was
studied by a superfusion technique in human embryonic kidney 293 cells stably transfected with the respective transporter cDNA and
loaded with the metabolically inert substrate
[3H]1-methyl-4-phenylpyridinium. Release was induced by
amphetamine, dopamine, and norepinephrine or by lowering the sodium or
chloride concentration in the superfusion buffer (iso-osmotic
replacement by lithium and isethionate, respectively). Efflux of
[3H]1-methyl-4-phenylpyridinium was analyzed at 30-s time
resolution. In both transporters, release induced by the substrates
amphetamine, dopamine, and norepinephrine followed the same time course
as release induced by the removal of chloride and was faster than that
caused by the removal of sodium. In the presence of low sodium (DAT: 10 mM; NET: 5 mM) none of the substrates was able to induce release from
either type of cell, but adding back sodium to control conditions
promptly restored the releasing action. In the presence of low chloride
(DAT: 3 mM; NET: 2 mM), however, amphetamine as well as the
catecholamines stimulated release from both types of cell. In contrast
with the ion dependence of release observed in superfusion experiments,
uptake initial rates of substrates at concentrations used in release
experiments were the same or even higher at low sodium than at low
chloride. The results indicate a decisive role of extracellular sodium
for carrier-mediated release unrelated to the sodium-dependent uptake
of the releasing substrate, and suggest a release mechanism different
from simple exchange diffusion considering only the amines as substrates.
This article has been cited by other articles:
|
|
 |
|
  C. Dipace, U. Sung, F. Binda, R. D. Blakely, and A. Galli Amphetamine Induces a Calcium/Calmodulin-Dependent Protein Kinase II-Dependent Reduction in Norepinephrine Transporter Surface Expression Linked to Changes in Syntaxin 1A/Transporter Complexes Mol. Pharmacol., January 1, 2007; 71(1): 230 - 239. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Seidel, E. A. Singer, H. Just, H. Farhan, P. Scholze, O. Kudlacek, M. Holy, K. Koppatz, P. Krivanek, M. Freissmuth, et al. Amphetamines Take Two to Tango: an Oligomer-Based Counter-Transport Model of Neurotransmitter Transport Explores the Amphetamine Action Mol. Pharmacol., January 1, 2005; 67(1): 140 - 151. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Gnegy, H. Khoshbouei, K. A. Berg, J. A. Javitch, W. P. Clarke, M. Zhang, and A. Galli Intracellular Ca2+ Regulates Amphetamine-Induced Dopamine Efflux and Currents Mediated by the Human Dopamine Transporter Mol. Pharmacol., July 1, 2004; 66(1): 137 - 143. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. J. Rodriguez, D. L. Roman, K. J. White, D. E. Nichols, and E. L. Barker Distinct Recognition of Substrates by the Human and Drosophila Serotonin Transporters J. Pharmacol. Exp. Ther., July 1, 2003; 306(1): 338 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Khoshbouei, H. Wang, J. D. Lechleiter, J. A. Javitch, and A. Galli Amphetamine-induced Dopamine Efflux. A VOLTAGE-SENSITIVE AND INTRACELLULAR Na+-DEPENDENT MECHANISM J. Biol. Chem., March 28, 2003; 278(14): 12070 - 12077. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Hu and J. B. Becker Effects of Sex and Estrogen on Behavioral Sensitization to Cocaine in Rats J. Neurosci., January 15, 2003; 23(2): 693 - 699. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Scholze, L. Norregaard, E. A. Singer, M. Freissmuth, U. Gether, and H. H. Sitte The Role of Zinc Ions in Reverse Transport Mediated by Monoamine Transporters J. Biol. Chem., June 7, 2002; 277(24): 21505 - 21513. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Kantor, G. H. K. Hewlett, Y. H. Park, S. M. Richardson-Burns, M. J. Mellon, and M. E. Gnegy Protein Kinase C and Intracellular Calcium Are Required for Amphetamine-Mediated Dopamine Release via the Norepinephrine Transporter in Undifferentiated PC12 Cells J. Pharmacol. Exp. Ther., June 1, 2001; 297(3): 1016 - 1024. [Abstract] [Full Text]
|
|
|
|
|
|
H. H. Sitte, B. Hiptmair, J. Zwach, C. Pifl, E. A. Singer, and P. Scholze Quantitative Analysis of Inward and Outward Transport Rates in Cells Stably Expressing the Cloned Human Serotonin Transporter: Inconsistencies with the Hypothesis of Facilitated Exchange Diffusion Mol. Pharmacol., April 16, 2001; 59(5): 1129 - 1137. [Abstract] [Full Text]
|
|
 |
 |
 |
|
 |
 |
 |
