Tang F, Hadjiconstantinou M, Pang S F
Neuroendocrinology. 1985 Feb;40(2):160-4. doi: 10.1159/000124068.
Pineal serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE) and dopamine (DA) were measured by high-pressure liquid chromatography with electrochemical detection and serum melatonin was measured by radioimmunoassay in rats aged 3 weeks, 8 weeks and 18 months. They were killed either at mid-light or mid-dark of a 12 h light:12 h dark cycle. Diurnal rhythms were observed for 5-HT and 5-HIAA in all ages studied while those for NE and DA were not observed in the 18-month-old animals. Pineal 5-HT and 5-HIAA were higher in 3-week-old rats at mid-dark, and lower at mid-light than in older animals. The pineal content of NE was lower in the 3-week-old rats at mid-dark and mid-light compared with that in the 8-week-old while the DA content was lower at mid-dark. In addition, pineal 5-HT, 5-HIAA, NE and DA were lower in the 18-month-old than in the 8-week-old animals at mid-dark. At mid-dark serum melatonin levels showed an age-related decrease. This study shows that an age-related decrease of pineal 5-HT, 5-HIAA, NE and DA can only be demonstrated at mid-dark and that the age-related decrease of melatonin may not be due to a decrease in sympathetic activity.
采用高压液相色谱电化学检测法测定3周龄、8周龄和18月龄大鼠松果体中的5-羟色胺（5-HT）、5-羟吲哚乙酸（5-HIAA）、去甲肾上腺素（NE）和多巴胺（DA），并采用放射免疫分析法测定血清褪黑素水平。在12小时光照：12小时黑暗周期的光照中期或黑暗中期处死大鼠。在所研究的所有年龄段中均观察到5-HT和5-HIAA的昼夜节律，而在18月龄动物中未观察到NE和DA的昼夜节律。3周龄大鼠在黑暗中期松果体中的5-HT和5-HIAA含量高于老年动物，在光照中期则低于老年动物。与8周龄大鼠相比，3周龄大鼠在黑暗中期和光照中期松果体中NE的含量较低，而在黑暗中期DA的含量较低。此外，18月龄动物在黑暗中期松果体中的5-HT、5-HIAA、NE和DA含量低于8周龄动物。在黑暗中期血清褪黑素水平呈现出与年龄相关的下降。本研究表明，仅在黑暗中期可证明松果体中5-HT、5-HIAA、NE和DA与年龄相关的下降，且褪黑素与年龄相关的下降可能并非由于交感神经活动的降低。
