Hadjiconstantinou M, Krajnc D, Rossetti Z, Neff N H
Department of Pharmacology, Ohio State University College of Medicine, Columbus 43210.
Brain Res. 1990 Nov 12;533(1):20-3. doi: 10.1016/0006-8993(90)91790-n.
When rats are placed in a lighted environment from the dark retinal DOPAC increases. There is no significant change of retinal dopamine (DA) under either lighting condition. Blockade of aromatic L-amino acid decarboxylase results in a more rapid accumulation of DOPA in the retina of animals in the light than in the dark implying that DA synthesis and metabolism are more rapid in the light than in the dark. Retinal DOPAC increases in the dark and in the light when rats are treated with the DA D2 antagonists sulpiride and spiperone. Treatment with the D2 agonist, quinpirole, lowers the content of DA in the retina of rats kept in the dark or exposed to light. D1 receptor drugs induce only limited changes in DA metabolism. We conclude that D2 receptors play a principal role for modulating DA synthesis and metabolism in the rat retina.
当大鼠从黑暗环境转移至明亮环境时，视网膜中的3,4-二羟基苯乙酸（DOPAC）会增加。在任何一种光照条件下，视网膜多巴胺（DA）均无显著变化。芳香族L-氨基酸脱羧酶被阻断后，光照下动物视网膜中多巴（DOPA）的积累比黑暗中更快，这意味着光照下DA的合成和代谢比黑暗中更快。当用DA D2拮抗剂舒必利和螺哌隆处理大鼠时，无论在黑暗还是光照条件下，视网膜DOPAC都会增加。用D2激动剂喹吡罗处理，会降低处于黑暗或光照环境下大鼠视网膜中DA的含量。D1受体药物仅能引起DA代谢的有限变化。我们得出结论，D2受体在调节大鼠视网膜中DA的合成和代谢方面起主要作用。
