Gatien M L, Hotchkiss A K, Dhabhar F S, Nelson R J
Department of Psychology, Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH 43210, USA.
J Neuroendocrinol. 2005 Nov;17(11):733-9. doi: 10.1111/j.1365-2826.2005.01371.x.
Photoperiod (day length) can modulate immune function. Whether these photoperiodic effects on immune function are mediated directly by a circadian photoperiodic time measurement system or indirectly by nonspecific (e.g. stressful) effects of light is unknown. To discriminate between these two possibilities, Siberian hamsters (Phodopus sungorus) were housed in either long or short photoperiods (LD 16 : 8 h or LD 8 : 16 h) or in 'skeleton' long or short photoperiods (LD 1 : 14 h: LD 1 : 8 h or LD 1 : 6 h: LD 1 : 16 h). In the skeleton photoperiods, both long- and short-day animals received 2 h of light per day. After 10 weeks in their respective photoperiods, hamsters were tested for an antigen specific immune response using a delayed type hypersensitivity (DTH) model. Reproductive and endocrine responses of hamsters in each of the skeleton photoperiods were equivalent to those in standard long or short days, respectively. Hamsters in skeleton short days and LD 8 : 16 increased DTH responses compared to hamsters in both long-day groups. DTH responses were equivalent in both long-day groups. These results suggest that the influences of day length on immune function potentially are due to circadian photoperiodic time measurement systems.
光周期（日照长度）能够调节免疫功能。目前尚不清楚这些对免疫功能的光周期效应是直接由昼夜光周期时间测量系统介导，还是由光的非特异性（如应激性）效应间接介导。为了区分这两种可能性，将西伯利亚仓鼠（Phodopus sungorus）饲养在长或短光周期（LD 16∶8小时或LD 8∶16小时）或“骨架式”长或短光周期（LD 1∶14小时∶LD 1∶8小时或LD 1∶6小时∶LD 1∶16小时）环境中。在骨架式光周期中，长日照和短日照动物每天均接受2小时光照。在各自的光周期环境中饲养10周后，使用迟发型超敏反应（DTH）模型检测仓鼠的抗原特异性免疫反应。每个骨架式光周期中的仓鼠的生殖和内分泌反应分别与标准长日照或短日照中的仓鼠相当。与两个长日照组的仓鼠相比，骨架式短日照和LD 8∶16中的仓鼠的DTH反应增强。两个长日照组的DTH反应相当。这些结果表明，日照长度对免疫功能的影响可能归因于昼夜光周期时间测量系统。
