Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Biol Reprod. 2013 Apr 4;88(4):83. doi: 10.1095/biolreprod.112.103697. Print 2013 Apr.
Photostimulation of retinal photoreceptors appears to inhibit reproductive activity in birds. In the present study, the involvement of serotonin and vasoactive intestinal peptide was investigated in relation to reproductive failure associated with retinal photostimulation. Hens at 23 wk of age were divided into six rooms equipped with individual cages. At 24 wk of age, three rooms were photostimulated (14L:10D) with white light (control). Three rooms had two parallel lighting systems, red (660 nm) and green (560 nm), which were both on during 6 h of the 14-h light period. Upon photostimulation, the red light was turned off after 6 h, and the green light was left on for a total of 14 h (Green). Five hens from each room served as controls, five hens were immunized against vasoactive intestinal peptide, and five hens received parachlorophenylalanine, an inhibitor of serotonin biosynthesis. Parachlorophenylalanine treatment increased reproductive performance and mRNA expression of GnRH-I, LH-beta and FSH-beta (P < 0.05) in the Green group to levels which did not differ from those of the White (control) group. Immunization against vasoactive intestinal peptide reduced plasma concentration and pituitary mRNA expression of prolactin but did not affect expression of gonadal axis genes. Collectively, the results suggest that retinal photostimulation inhibits the reproductive axis through serotonin and not through vasoactive intestinal peptide.
光刺激视网膜感光细胞似乎能抑制鸟类的生殖活动。本研究探讨了与光刺激相关的生殖失败有关的 5-羟色胺和血管活性肠肽的作用。23 周龄母鸡被分为 6 个房间，每个房间配备一个单独的笼子。在 24 周龄时，3 个房间（对照）用白光（14L：10D）进行光刺激。另外 3 个房间有两个平行的照明系统，红色（660nm）和绿色（560nm），在 14 小时的光照周期中，这两个系统都开启 6 小时。在光刺激时，红光在 6 小时后关闭，绿光总共开启 14 小时（绿光组）。每个房间有 5 只母鸡作为对照，5 只母鸡接受血管活性肠肽免疫，5 只母鸡接受对氯苯丙氨酸治疗，这是一种 5-羟色胺生物合成抑制剂。对氯苯丙氨酸治疗增加了绿光组母鸡的生殖性能和 GnRH-I、LH-β和 FSH-β 的 mRNA 表达（P<0.05），使其水平与白光（对照）组没有差异。血管活性肠肽免疫降低了血浆浓度和促乳素的垂体 mRNA 表达，但不影响性腺轴基因的表达。总的来说，结果表明，光刺激通过 5-羟色胺而不是血管活性肠肽抑制生殖轴。
