Department of Physiology, Laboratorio de Fisiología Animal, Facultad de Biología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
Arch Insect Biochem Physiol. 2019 Dec;102(4):e21605. doi: 10.1002/arch.21605. Epub 2019 Jul 22.
The pathways of insect melatonin (MEL) biosynthesis apparently follow the same routes as those identified in vertebrates but information on MEL synthesis variations related with serotonin (5-HT), 5-hydroxy-indole acetic acid (5HIAA), and N-acetylserotonin (NAS) levels, as well as 5-HT N-acetyltransferase (NAT) activity throughout the day, is very limited in the insect nervous system. In the present study, the levels of MEL, metabolites (5-HT, NAS, and 5-HIAA) and enzyme NAT were determined in the optic lobes and the midbrain of the grasshopper Oedipoda caerulescens, in conditions of light and darkness. In both tissues, a different pattern of MEL synthesis was observed over the light/dark cycle. Variations in the levels of 5-HT, NAS and NAT activity related to the synthesis of cerebral MEL follow a pattern very similar to that observed in the pineal of mammals, with a peak of synthesis in the first half of the scotophase. Also, we observed differences in the metabolism of 5-HT between the optic lobes and the midbrain light/dark-dependent.
昆虫褪黑素（MEL）生物合成的途径显然与脊椎动物中确定的途径相同，但有关与血清素（5-HT）、5-羟吲哚乙酸（5HIAA）和 N-乙酰血清素（NAS）水平以及 5-HT N-乙酰转移酶（NAT）活性相关的 MEL 合成变化的信息，在昆虫神经系统中非常有限。在本研究中，测定了在光和暗条件下，草蜢 Oedipoda caerulescens 的视叶和中脑中 MEL、代谢物（5-HT、NAS 和 5-HIAA）和酶 NAT 的水平。在这两种组织中，在光/暗周期上观察到了不同的 MEL 合成模式。与大脑 MEL 合成相关的 5-HT、NAS 和 NAT 活性水平的变化遵循与哺乳动物松果体中观察到的非常相似的模式，在暗期的前半段合成达到峰值。此外，我们还观察到视叶和中脑光/暗依赖之间 5-HT 代谢的差异。
