Evidence for D2 receptor regulation of dopamine release in the goldfish retina.
The possible existence of a dopamine D2 receptor-mediated regulation of dopamine release was investigated in the goldfish retina. Isolated retinas were preloaded with [3H]dopamine and superfused with D2 dopamine receptor agonists or antagonists to determine if there was an effect on [3H]dopamine release. The D2 receptor antagonist sulpiride increased both baseline [3H]-dopamine release and [3H]dopamine release induced by an increase in extracellular potassium concentration. The D2 receptor agonists LY-171555 and RU-24213 did not reduce baseline [3H]dopamine release but completely inhibited [3H]dopamine release induced by an increase in [K+]o. This action of the D2 agonists was blocked by sulpiride. These studies demonstrate the existence of D2 receptor, possibly autoreceptor, regulation of dopamine release in the teleost retina.
Rashid
K
K
Division of Anatomy and Experimental Morphology, McMaster University, Hamilton, Ontario, Canada.
Baldridge
W H
WH
Ball
A K
AK
D000818:Animals; D001345:Autoradiography; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D006054:Goldfish; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007700:Kinetics; D011188:Potassium / Q000494:pharmacology; D019257:Quinpirole; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology*; D012160:Retina / Q000378:metabolism*; D013469:Sulpiride / Q000494:pharmacology; D013997:Time Factors; D014316:Tritium
D015259:Dopamine Agents; D004873:Ergolines; D017448:Receptors, Dopamine D2; D014316:Tritium; D019257:Quinpirole; D013469:Sulpiride; D011188:Potassium; D004298:Dopamine