Djamgoz M B, Sekaran S, Angotzi A R, Haamedi S, Vallerga S, Hirano J, Yamada M
Department of Biology, Imperial College of Science, Technology and Medicine, London, UK.
Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1199-203. doi: 10.1098/rstb.2000.0667.
The role of nitric oxide (NO) as a novel neurochemical mechanism controlling light adaptation of the outer retina is discussed by considering mainly published results. The emphasis is on the retinae of fishes and amphibia, but some data from the mammalian (rabbit) retinae have also been included for completeness. In the fish retina, application of NO donors in the dark caused light-adaptive photomechanical movements of cones. The normal effect of light adaptation in inducing cone contractions was suppressed by pretreatment of retinae with an NO scavenger. NO donors modulated horizontal cell activity by uncoupling the cells' lateral gap junctional interconnections and enhancing negative feedback to cones, again consistent with a light-adaptive role of NO. Direct evidence for light adaptation-induced release of NO has been obtained in fish (carp) and rabbit retinae. The results strongly suggest that control of retinal light adaptation is, under multiple neurochemical control, with NO and dopamine having an interactive role.
主要依据已发表的研究结果，探讨了一氧化氮（NO）作为一种新型神经化学机制在控制视网膜外层光适应过程中的作用。重点关注鱼类和两栖动物的视网膜，但为了内容的完整性，也纳入了一些来自哺乳动物（兔子）视网膜的数据。在鱼类视网膜中，在黑暗条件下应用NO供体可引发视锥细胞的光适应性光机械运动。视网膜用NO清除剂预处理后，光适应诱导视锥细胞收缩的正常效应受到抑制。NO供体通过解开细胞间的横向缝隙连接并增强对视锥细胞的负反馈来调节水平细胞的活动，这再次表明NO具有光适应作用。在鱼类（鲤鱼）和兔子视网膜中已获得光适应诱导NO释放的直接证据。结果有力地表明，视网膜光适应受多种神经化学物质的控制，其中NO和多巴胺具有相互作用。
