Morita M, Hall F, Best J B, Gern W
J Exp Zool. 1987 Mar;241(3):383-8. doi: 10.1002/jez.1402410314.
Endogenous melatonin was detected by high-performance liquid chromatography (HPLC) with electrochemical detection (EC) in the head of the planarian Dugesia dorotocephala. The identity of this elution peak was further confirmed by radioimmunoassay. In groups of planarians adapted to either normal or reversed photoperiods, the melatonin levels were always higher in those heads collected in the dark period than in those collected in the light period. This indicates that primitive animals such as planarians have already evolved a melatonin-metabolizing system that is photically driven in a manner suggestive of the way melatonin synthesis is influenced by light and dark cycles in vertebrates.
采用高效液相色谱法（HPLC）结合电化学检测（EC）对头节涡虫（Dugesia dorotocephala）头部的内源性褪黑素进行了检测。通过放射免疫测定法进一步证实了该洗脱峰的特性。在适应正常或反向光周期的涡虫群体中，黑暗期采集的头部褪黑素水平始终高于光照期采集的头部。这表明，像涡虫这样的原始动物已经进化出一种褪黑素代谢系统，该系统受光照驱动，其方式类似于脊椎动物中褪黑素合成受明暗周期影响的方式。
