Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by TSUDZUKI, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by TSUDZUKI, T.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1984, Vol. 95, No. 6 1585-1592
© 1984 Japanese Biochemical Society

research-article

{delta}pH-Dependent and -Independent Uptake of [3H]Dopamine by Synaptic Vesicles Isolated from Rat Brain

Toshihiro TSUDZUKI

Department of Biochemistry, Nagoya City University Medical School Mizuho-ku, Nagoya, Aichi 467

The dopamine (DA)-translocating mechanism of synaptic vesicles isolated from rat brain has been studied in the presence of an artificially imposed {delta}pH on the vesicle membranes (acidic inside with respect to the external medium) without the aid of ATP-Mg2+. Under the experimental conditions, [3H]DA uptake by the synaptic vesicles was driven by two different, i.e. {delta}pH-dependent and -independent processes. Both processes appeared to be carrier-mediated based on the inhibition by NEM (N-ethylmaleimide), an -SH reagent, and by nomifensine, a DA uptake blocker at nerve terminals. The DA carrier of the vesicles was similar to that of the nerve terminal plasma membrane with respect to their susceptibility to nomifensine. The {delta}pH-dependent uptake was transient and most of the incorporated DA was easily lost from the vesicles. On the other hand, the {delta}H-independent uptake increased with time and the amine was retained in the vesicles. The initial rate of the {delta}pH- independent uptake was lower than that of the {delta}pH-dependent one but their extents were comparable with each other. These results indicate that rat brain synaptic vesicles have a DA uptake system requiring no ATP hydrolysis.

A preparation of synaptic vesicles used here exhibited an inwardly directed proton translocation in the presence of ATP-Mg2+ when monitored by following changes in the fluorescence of ANS (8-anilino-1-naphthalene sulfonate). However, time course of the {delta}pH-generation was not influenced by the addition of 1 mM DA. Therefore these results suggest that there is no close correlation between the active proton translocation and the DA uptake in synaptic vesicles. Since the vesicle preparation was usually contaminated with a small amount of mitochondrial membrane fragments judging from the presence of respiratory chain-cytochromes, active proton translocation might be at least partially due to the contaminating submitochondrial particles.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J BiochemHome page
T. Tsudzuki
Isolation of Small Agranular Synaptic Vesicles of Rat Brain by Gel Filtration Chromatography
J. Biochem., April 1, 2003; 133(4): 437 - 443.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.