Department of Educative Science, University of Catania, Catania, Italy.
Department of Neurology, San Paolo Hospital, Savona, Italy.
Neuropsychiatr Dis Treat. 2014 May 20;10:907-14. doi: 10.2147/NDT.S63459. eCollection 2014.
Agomelatine, the first melatonergic antidepressant, has been postulated to enhance the dopaminergic activity at the central nervous system by 5-hydroxytryptamine receptor type 2C (5-HT2C) antagonism, yet the impact of melatonergic agonism on this pathway is unclear. Previous studies employing simplified, yet reliable, proxy (retinal) measures of the central nervous system dopaminergic activity, namely the standard electroretinogram (ERG) technique, suggested a reduction of the dopaminergic activity of the main ERG parameter, the b-wave, by pure melatonin, notably a hormone devoid of any antidepressant activity. Therefore, the antidepressant effects of the melatonergic antidepressant drug agomelatine should be reflected by a differential b-wave trend at ERG versus the effect exerted by pure melatonin, which was eventually found to be due to a contrasting effect on central dopaminergic transmission between the two drugs.
The aim of the present preliminary ERG study carried out on healthy volunteers (n=23) receiving agomelatine was to explore the impact of this antidepressant drug on b-wave amplitude and latency of cones in daylight conditions using standard ERG.
As postulated, agomelatine induced an enhancement of retinal dopaminergic activity, in contrast to what has been previously documented for melatonin.
Given the limits of this explorative study, especially the lack of a control group and that of a luminance response function to measure retinal sensitivity, further studies in clinical samples are recommended to allow more tenable conclusions about the potential role of ERG in discriminating between 5-HT antagonism and melatonergic (MT) agonism in relationship to the claimed antidepressant effect of agomelatine.
阿戈美拉汀是第一种褪黑素能抗抑郁药，据推测，它通过 5-羟色胺受体 2C（5-HT2C）拮抗作用增强中枢神经系统的多巴胺活性，然而，褪黑素能激动剂对该途径的影响尚不清楚。先前的研究采用简化但可靠的中枢神经系统多巴胺活性替代（视网膜）测量方法，即标准视网膜电图（ERG）技术，表明纯褪黑素降低了主要 ERG 参数，即 b 波的多巴胺活性，特别是一种没有任何抗抑郁作用的激素。因此，褪黑素能抗抑郁药阿戈美拉汀的抗抑郁作用应该反映在 ERG 上的 b 波趋势与纯褪黑素的作用之间存在差异，最终发现这是由于两种药物对中枢多巴胺传递的对比作用所致。
本研究旨在探讨这种抗抑郁药对健康志愿者（n=23）在日光条件下视锥细胞 b 波振幅和潜伏期的影响，采用标准 ERG 进行初步 ERG 研究。
正如预期的那样，阿戈美拉汀诱导了视网膜多巴胺活性的增强，与先前记录的褪黑素相反。
鉴于这项探索性研究的局限性，特别是缺乏对照组和测量视网膜敏感性的亮度反应函数，建议在临床样本中进行进一步研究，以便更有把握地得出关于 ERG 在区分 5-HT 拮抗作用和褪黑素（MT）激动作用与阿戈美拉汀声称的抗抑郁作用之间的潜在作用的结论。
