Vollrath L, Karasek M, Kosaras B, Kunert-Radek J, Lewinski A
Cell Tissue Res. 1985;242(3):607-11. doi: 10.1007/BF00225426.
Previous studies have shown that the "synaptic" ribbons (SR) and spherules (SS) of the mammalian pineal gland may respond differently under physiological and various experimental conditions. The aim of the present study was to gain insight into the mechanisms that may be responsible for the numerical changes of these organelles during a 24-h cycle. As the possibility exists that the structures are influenced by substances synthesized within the pinealocyte, rat pineal glands were cultured with and without added melatonin or serotonin, using an experimental protocol such that the addition of melatonin and serotonin mimicks the circadian changes of the respective substances within the pineal. The tissue was processed for electron microscopy and the numbers of SR and SS were counted in a unit area of pineal tissue. The results obtained indicate that melatonin added to the incubation medium increases the number of SR in the first half of the night; serotonin decreases SR numbers in the morning. SS numbers, by contrast, decrease following melatonin administration in the afternoon, and increase in the morning following serotonin administration. It thus appears that the numbers of SR and SS are influenced by melatonin and serotonin and that the two structures are regulated by differential, but nevertheless biochemically closely related mechanisms.
以往的研究表明，哺乳动物松果体的“突触”带（SR）和小球（SS）在生理和各种实验条件下可能有不同反应。本研究的目的是深入了解这些细胞器在24小时周期内数量变化的可能机制。由于存在这些结构受松果体细胞内合成物质影响的可能性，因此采用一种实验方案，在添加和不添加褪黑素或血清素的情况下培养大鼠松果体，使得添加褪黑素和血清素模拟松果体内各自物质的昼夜变化。将组织进行电子显微镜处理，并在松果体组织的单位面积内计数SR和SS的数量。获得的结果表明，添加到孵育培养基中的褪黑素在夜间前半段增加SR的数量；血清素在早晨减少SR的数量。相比之下，下午给予褪黑素后SS的数量减少，而早晨给予血清素后SS的数量增加。因此，似乎SR和SS的数量受褪黑素和血清素的影响，并且这两种结构受不同但在生化上密切相关的机制调节。
