Lissoni P, Rovelli F, Brivio F, Brivio O, Fumagalli L
Division of Radiation Oncology, San Gerardo Hospital, Monza, Italy.
Nat Immun. 1998;16(1):1-5. doi: 10.1159/000069464.
It has been demonstrated that cytokine activities are under neuroendocrine control, recently mainly exerted by the pineal gland through the circadian secretion of its main hormone melatonin (MLT). It is mainly released during the night, but at present it is still unclear which relation exists between MLT and the circadian secretion of cytokines. This study was performed to evaluate the circadian secretion of IL-2, IL-6, IL-10 and IL-12 in relation to that of MLT. The study included 10 healthy volunteers whose venous blood samples were collected at 8 a.m., noon, 4 p.m., 8 p.m., 1 a.m. and 4 a.m. The mean levels of MLT were significantly higher during the night than during the light phase of the day. Similarly, IL-2 mean levels significantly increased during the night. IL-6 mean values were higher during the light period of the day without, however, any significant differences with respect to the nocturnal mean levels. Finally, no substantial circadian variation was seen in IL-10 and IL-12 mean concentrations. These results show that IL-2 secretion increases during the night, concomitantly to that of the pineal hormone MLT, whereas there is no evidence of a circadian secretion for the other cytokines. Since the pineal gland has been proven to stimulate IL-2 endogenous production, the nocturnal increase in IL-2 blood concentrations could depend at least in part on the promoting action of MLT, whose release increases during the dark period of the day.
已经证明细胞因子的活性受神经内分泌控制，最近主要是由松果体通过其主要激素褪黑素（MLT）的昼夜分泌来发挥作用。MLT主要在夜间释放，但目前MLT与细胞因子的昼夜分泌之间存在何种关系仍不清楚。本研究旨在评估白细胞介素-2（IL-2）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）和白细胞介素-12（IL-12）与MLT的昼夜分泌关系。该研究纳入了10名健康志愿者，于上午8点、中午、下午4点、晚上8点、凌晨1点和凌晨4点采集他们的静脉血样本。MLT的平均水平在夜间显著高于白天的光照阶段。同样，IL-2的平均水平在夜间也显著升高。IL-6的平均值在白天的光照期较高，但与夜间平均水平相比无显著差异。最后，IL-10和IL-12的平均浓度未见明显的昼夜变化。这些结果表明，IL-2的分泌在夜间增加，与松果体激素MLT的分泌同步，而其他细胞因子没有昼夜分泌的证据。由于已证明松果体可刺激IL-2的内源性产生，夜间IL-2血浓度的升高可能至少部分取决于MLT的促进作用，MLT在白天的黑暗期释放增加。
