Krasovich M, Benson B
Cell Tissue Res. 1979;203(3):457-67. doi: 10.1007/BF00233274.
The number of granulated vesicles in mouse pinealocytes exhibit a distinct circadian rhythm which is abolished by superior cervical ganglionectomy. Since melatonin treatment markedly effects the number of pinealocytic granulated vesicles, it was suggested that a relationship may exist between norepinephrine, melatonin, and the synthesis and/or secretion of pinealocyte granulated vesicles. The present study was undertaken in an attempt to clarify this relationship. Mice were housed in an environmental chamber under controlled lighting (12L/12D), and were treated with either reserpine, a drug which depletes serotonin and norepinephrine, or p-chlorophenylalanine (p-CPA), an inhibitor of serotonin synthesis. They were sacrificed at various times over a twenty-four hour period, and granulated vesicles present in the pinealocytes were quantitated in thin cross sections through pericapillary areas. Reserpine treatment resulted in a marked increase in the number of granulated vesicles during the dark, but led to a slight decrease during the photoperiod. Treatment with p-CPA produced no significant effect. The results of this study do not support our previous theory that melatonin plays an important role in the regulation of the pinealocyte secretory process, but instead points more directly to the significant role that norepinephrine has in controlling pinealocyte secretion.
小鼠松果体细胞中颗粒小泡的数量呈现出明显的昼夜节律，而这种节律在颈上神经节切除术后消失。由于褪黑素处理对松果体细胞颗粒小泡的数量有显著影响，因此有人提出去甲肾上腺素、褪黑素与松果体细胞颗粒小泡的合成和/或分泌之间可能存在某种关系。本研究旨在阐明这种关系。将小鼠饲养在可控光照（12小时光照/12小时黑暗）的环境舱中，并用利血平（一种消耗血清素和去甲肾上腺素的药物）或对氯苯丙氨酸（p-CPA，一种血清素合成抑制剂）进行处理。在24小时内的不同时间将它们处死，并通过毛细血管周围区域的薄切片对松果体细胞中存在的颗粒小泡进行定量。利血平处理导致黑暗期间颗粒小泡数量显著增加，但在光周期期间导致轻微减少。p-CPA处理未产生显著影响。本研究结果不支持我们之前关于褪黑素在调节松果体细胞分泌过程中起重要作用的理论，而是更直接地指出了去甲肾上腺素在控制松果体细胞分泌中所起的重要作用。
