Lima L, Urbina M
Laboratorio de Neuroquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
J Neurosci Res. 1994 Dec 1;39(5):595-603. doi: 10.1002/jnr.490390511.
The concentration of dopamine, and its metabolites 3,4-dihydroxyphenylacetic and homovanillic acids, as well as serotonin and its metabolite 5-hydroxyindoleacetic acid, were determined in the retina of two teleosts, C. auratus (goldfish) and E. plumieri (mojarra), and two mammals, R. norvegicus (rat) and O. cuniculus (rabbit). The turnover rate of these monoamines were investigated in the four species by the calculation of the ratio monoamine/metabolite as an indirect index, and in goldfish and rat by the inhibition of the synthesis with alpha-methyl-p-tyrosine or p-chlorophenylalanine, by the increase in dopamine or serotonin by the corresponding precursors, 3,4-dihydroxyphenylalanine or 5-hydroxytryptophan, and by inhibition of monoaminooxidase with pargyline. The modulation by light and dark stimulation was studied in the goldfish and the rat. Differences in the concentration and turnover rate were observed among the species. Serotonin concentration was higher in the teleosts. The administration of inhibitors of dopamine and serotonin synthesis differentially decreased the levels of the monoamines in the retina of goldfish and rat. The rate of formation of dopamine and serotonin by the corresponding precursors was much higher in the goldfish than in the rat. Pargyline administration decreased 3,4-dihydroxyphenylacetic and 5-hydroxyindoleacetic acids at different rates and time dependency in the retina of goldfish and rat. Dopamine and serotonin concentration did not exhibit high modifications by the inhibitor, suggesting the function of regulatory mechanisms or additional effect of pargyline at other sites different from monoaminooxidase.(ABSTRACT TRUNCATED AT 250 WORDS)
测定了两种硬骨鱼（金鲫鱼和梅氏丽体鱼）以及两种哺乳动物（挪威大鼠和家兔）视网膜中多巴胺及其代谢产物3,4-二羟基苯乙酸和高香草酸，以及血清素及其代谢产物5-羟基吲哚乙酸的浓度。通过计算单胺/代谢产物的比率作为间接指标，研究了这四种物种中这些单胺的周转率；在金鱼和大鼠中，通过用α-甲基-对-酪氨酸或对氯苯丙氨酸抑制合成、用相应前体3,4-二羟基苯丙氨酸或5-羟色氨酸增加多巴胺或血清素以及用帕吉林抑制单胺氧化酶来进行研究。在金鱼和大鼠中研究了光暗刺激的调节作用。观察到不同物种之间在浓度和周转率上存在差异。硬骨鱼中的血清素浓度较高。多巴胺和血清素合成抑制剂的给药分别降低了金鱼和大鼠视网膜中这些单胺的水平。金鱼中相应前体生成多巴胺和血清素的速率比大鼠中高得多。在金鱼和大鼠视网膜中，帕吉林给药以不同速率和时间依赖性降低了3,4-二羟基苯乙酸和5-羟基吲哚乙酸。多巴胺和血清素浓度未因该抑制剂而表现出高度变化，这表明存在调节机制的作用或帕吉林在不同于单胺氧化酶的其他位点具有额外作用。（摘要截短于250字）
