Lan C T, Hsu J C, Ling E A
Department of Anatomy, Chung-Shan Medical and Dental College, No. 110, Sec. 1, Chien Kuo North Road, Taichung, Taiwan.
Brain Res. 2001 Aug 10;910(1-2):1-11. doi: 10.1016/s0006-8993(01)02714-7.
The effects of sleep deprivation with or without melatonin treatment on the pineal morphology in rats were studied. Five days after sleep deprivation and using electron microscopy, many of the pinealocytes exhibited structural alterations including dilation of the cisternae of the rough/smooth endoplasmic reticulum, Golgi saccules and mitochondria, and an increase in the numbers of lipid droplets, vacuoles and dense-core vesicles. These features were considered as morphological evidence of increased synthesis or secretion by the pineal gland. In addition, numerous membranous profiles, considered to be degraded cellular organelles, were observed in some pinealocytes and sympathetic nerve terminals. It is suggested that the occurrence of degenerating organelles had resulted from the deleterious effect of sleep deprivation. This may be attributed to an overload of secretory activity of the pineal gland during stress elicited by the long-term sleep deprivation, leading to functional exhaustion and irreversible damage of the oxidation-related organelles. In sleep-deprived rats receiving a single injection of melatonin (10 mg/kg) for 5 consecutive days, the above features indicative of pinealocytic activation were attenuated. In fact, all signs of degeneration of cellular organelles were rarely found. These results suggest that the pineal gland is itself a target for exogenously administered melatonin. Thus, melatonin when administered systemically may be used as a potential neuroprotective drug against neuronal damage induced by sleep deprivation.
研究了睡眠剥夺（伴或不伴褪黑素治疗）对大鼠松果体形态的影响。睡眠剥夺5天后，采用电子显微镜观察发现，许多松果体细胞呈现结构改变，包括粗面/滑面内质网池、高尔基囊泡和线粒体扩张，脂滴、空泡和致密核心囊泡数量增加。这些特征被视为松果体合成或分泌增加的形态学证据。此外，在一些松果体细胞和交感神经末梢中观察到大量被认为是降解细胞器的膜性结构。提示退化细胞器的出现是睡眠剥夺的有害作用所致。这可能归因于长期睡眠剥夺引发的应激期间松果体分泌活动过载，导致氧化相关细胞器功能衰竭和不可逆损伤。在连续5天接受单次注射褪黑素（10 mg/kg）的睡眠剥夺大鼠中，上述表明松果体细胞激活的特征有所减轻。事实上，很少发现细胞器退化的迹象。这些结果表明，松果体本身是外源性给予褪黑素的作用靶点。因此，全身给药时，褪黑素可用作一种潜在的神经保护药物，以对抗睡眠剥夺诱导的神经元损伤。
