Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life, Earth & Environment, University of Namur, Namur, Belgium.
J Pineal Res. 2019 Aug;67(1):e12573. doi: 10.1111/jpi.12573. Epub 2019 Apr 19.
The pineal gland is the main organ involved in the transduction process converting environmental light information into a melatonin response. Since light environment was described as an important factor that could affect physiology of teleosts, and because melatonin is a crucial hormone regulating numerous physiological processes, we hypothesized that environmental light may act on both stress and circadian axes which in turn could influence the immune status of pike perch. Therefore, we investigated the effects of two light spectra (red and white) and two light intensities (10 and 100 lx) with a constant photoperiod 12L /12D on pike perch physiological and immune responses. Samples were collected at 04:00 and 16:00 at days 1 and 30 of the experiment. Stress markers, plasma melatonin levels, humoral innate immune markers, and expression of key immune genes in the head kidney were assessed. Light intensity clearly affected pike perch physiology. This included negative growth performances, increase in stress status, decrease in plasma melatonin levels, and immune depression. Light spectrum had only little influences. These results demonstrate that high stress status may have impacted melatonin production and secretion by the pineal organ. The drop in circulating melatonin and the increase in stress status may both be involved in the immune suppression.
松果腺是将环境光信息转换为褪黑素反应的主要器官。由于光环境被描述为影响硬骨鱼类生理学的重要因素，而褪黑素是调节许多生理过程的关键激素，我们假设环境光可能作用于应激和昼夜节律轴，进而影响鲈鱼的免疫状态。因此，我们研究了两种光谱（红色和白色）和两种光照强度（10 和 100 lx）在恒定光周期 12L / 12D 对鲈鱼生理和免疫反应的影响。在实验的第 1 天和第 30 天的 04:00 和 16:00 采集样本。评估应激标志物、血浆褪黑素水平、体液固有免疫标志物和头肾关键免疫基因的表达。光照强度明显影响鲈鱼的生理机能。这包括负生长表现、应激状态增加、血浆褪黑素水平下降和免疫抑制。光谱的影响则较小。这些结果表明，高应激状态可能影响松果腺的褪黑素产生和分泌。循环褪黑素的下降和应激状态的增加都可能参与免疫抑制。
