Regulation of dopamine uptake in rat striatal tissue by NMDA receptors as measured using rotating disk electrode voltammetry.
Rotating disk electrode (RDE) voltammetry was used to examine the effect of N-methyl-D-aspartate (NMDA) on the initial velocity of dopamine (DA) uptake in suspensions of rat striatal tissue. Transport velocities were determined by measuring the rate of clearance of 2 microM DA added to the tissue suspension. NMDA (200 microM) was found to increase the initial velocity of DA transport from 548 +/- 28 to 803 +/- 63 pmol/s per g tissue (mean +/- SEM; P < 0.005). The increase was reversed by the competitive NMDA antagonist AP5, and thus appears to be receptor-mediated. In a separate experiment, lower concentrations of NMDA (20-100 microM) yielded a high correlation (r = 0.96; P < 0.05) of velocity versus concentration. Kainic acid (10 microM) also was found to increase the initial rate of uptake, from 505 +/- 34 to 702 +/- 71 pmol/s per g (P < 0.05). The results of this study indicate that the rate of DA uptake in the striatum can be modulated in vitro by presynaptic ionotropic glutamate receptors.
Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
S M
SM
Welch
J B
JB
Justice
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000494:pharmacology; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D016202:N-Methylaspartate / Q000378:metabolism / Q000494:pharmacology; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000378:metabolism*; D017661:Receptors, Presynaptic / Q000187:drug effects
D018492:Dopamine Antagonists; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D017661:Receptors, Presynaptic; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D007608:Kainic Acid; D004298:Dopamine