Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-2-9
pubmed:abstractText
Amphetamine-like psychostimulants are thought to produce rewarding effects by increasing dopamine levels at mesolimbic synapses. Paradoxically, dopamine uptake blockers, which generally increase extracellular dopamine, inhibit amphetamine-induced dopamine overflow. This effect could be due to either inhibition of amphetamine uptake or inhibition of dopamine efflux through the transporter (reverse transport). We used weak bases and dopamine uptake blockers in ventral midbrain neuron cultures to separate the effects on blockade of amphetamine uptake from reverse transport of dopamine. Amphetamine, ammonium chloride, tributylamine, and monensin, at concentrations that produce similar reductions in acidic pH gradients, increased dopamine release. This effect was inhibited by uptake blockers. Although in the case of amphetamine the inhibition of release could have been due to blockade of amphetamine uptake, inhibition also occurred with weak bases that are not transporter substrates. This suggests that reduction of vesicular pH gradients increases cytoplasmic dopamine which in turn promotes reverse transport. Consistent with this model, extracellular 3,4-dihydroxyphenylacetic acid was increased by ammonium chloride and monensin, as would be expected with elevated cytoplasmic dopamine levels. These findings extend the weak base mechanism of amphetamine action, in which amphetamine reduces vesicular pH gradients resulting in increased cytoplasmic dopamine that promotes reverse transport.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
527-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Amphetamine and other weak bases act to promote reverse transport of dopamine in ventral midbrain neurons.
pubmed:affiliation
Department of Psychiatry, Columbia University, New York, New York 10032.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't