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D 2 Receptors May Modulate the Function of the Striatal Transporter for Dopamine: Kinetic Evidence from Studies In Vitro and In Vivo
Author(s) -
Meiergerd Susan M.,
Patterson Terrell Ann,
Schenk James O.
Publication year - 1993
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1993.tb02185.x
Subject(s) - dopamine transporter , dopamine , in vivo , transporter , in vitro , neuroscience , chemistry , receptor , dopamine plasma membrane transport proteins , dopamine receptor , biology , biochemistry , dopaminergic , gene , genetics
Recently it was hypothesized by others that the D 2 dopamine receptor can regulate the uptake of dopamine. However, the evidence in support of this hypothesis, although compelling, was not based on observations related to direct measures of the kinetic activity of the transporter itself. Here kinetic evidence in support of this hypothesis is shown. The apparent time‐resolved initial velocity of the transport of 1.0 μ M dopamine into striatal suspensions, measured using rotating disk electrode voltammetry, was found to increase in the presence of the D 2 receptor agonist, quinpirole, at 100 μ M . This effect was reversed by sulpiride. In separate studies it was shown that acute and chronic treatments with haloperidol at 0.5 mg/kg, i.p., reduced the reuptake transport of dopamine in vivo following intrastriatal stimulation of its release by K + . Thus, it appears that D 2 receptors may influence the functioning of the striatal transporter for dopamine. These results are consistent with a model in which presynaptically released dopamine may feed back onto the function of its transporter to increase the velocity of the clearance of synaptic dopamine following an action potential, suggesting the existence of a mechanism, in addition to release and synthesis modulation, for fine‐tuning dopaminergic chemical signaling.