Kemali M, Kemali D, Lovero N, Maj M, Milici N
Istituto di Cibernetica CNR, Naples, Italy.
Pharmacopsychiatry. 1987 Sep;20(5):224-6. doi: 10.1055/s-2007-1017109.
Pigment screening (PS) is a phenomenon occurring in the retina of lower vertebrates, which consists in the dispersion, induced by the light, of melatonin granules into processes of the pigment epithelium which extend between photoreceptors, and in the aggregation, induced by the dark, of the same granules within the cell bodies of the pigment epithelium. It has been hypothesized that this phenomenon might be modulated by melatonin, which is present not only in the pineal but also in the retina, and whose retinal content is high in the dark and low in the light. In the present study we demonstrate that a single intraperitoneal injection of lithium chloride affects in a peculiar way PS of light-adapted frogs and of frogs subjected to natural day/night conditions, but not that of dark-adapted frogs. The implications of this findings are briefly discussed, also in view of the reported effect of lithium on the 24-hour rhythm of retinal melatonin, and of the possible relationship between this effect and the altering properties of lithium on other biological rhythms.
色素筛选（PS）是一种发生在低等脊椎动物视网膜中的现象，它包括在光的诱导下，褪黑素颗粒分散到位于光感受器之间的色素上皮细胞的突起中，以及在黑暗的诱导下，相同颗粒在色素上皮细胞体内聚集。据推测，这种现象可能受褪黑素调节，褪黑素不仅存在于松果体中，也存在于视网膜中，其视网膜含量在黑暗中高而在光照下低。在本研究中，我们证明单次腹腔注射氯化锂会以一种特殊的方式影响适应光照的青蛙以及处于自然昼夜条件下的青蛙的色素筛选，但不影响暗适应青蛙的色素筛选。鉴于锂对视网膜褪黑素24小时节律的报道影响，以及这种影响与锂对其他生物节律的改变特性之间可能存在的关系，我们简要讨论了这一发现的意义。
