Cernuda-Cernuda R, Huerta J J, Muñoz Llamosas M, Alvarez-Uría M, García-Fernández J M
Department of Morphology and Cell Biology, University of Oviedo, Spain.
Histol Histopathol. 2000 Oct;15(4):1087-92. doi: 10.14670/HH-15.1087.
Relatively little is known about the effects of melatonin on the aging of the pineal, the organ which is the main place for synthesis of this hormone. Using simple morphometric methods, some parameters of the pineal gland, such as total volume, number of pinealocytes and pinealocyte volume were estimated in two mice strains: normal CBA and melatonin-deficient C57BL/6J. Two age groups, 6 weeks and 10 months, were studied in order to evaluate possible differential age-related changes between both strains. Pineals of both strains have similar morphometric and morphological features at 6 weeks of age. This suggests that pineal development, which has already concluded at 6 weeks of age, is not affected by the absence of melatonin synthesis in the pinealocytes. Later on, CBA pineal showed an increase in size caused by cellular hypertrophy. In contrast, the C57BL/6J pineal volume decreased by loss of pinealocytes in the same period of time. Semithin sections analysed by light microscopy did not show that this cell death was evident in the C57BL/6J strain at any of the ages studied. Thus, a gradual loss of pinealocytes could be hypothesised in these pineals. These results suggest that pineal melatonin could have a role in the maintenance of pinealocyte viability and the increase of pineal size which takes place after development. The abnormal pattern observed in the C57BL/6J pineal should be taken into account in future studies on this gland.
关于褪黑素对松果体衰老的影响，人们了解相对较少，而松果体是合成这种激素的主要场所。采用简单的形态测量方法，对两种小鼠品系（正常的CBA和褪黑素缺乏的C57BL/6J）的松果体的一些参数进行了估计，如总体积、松果体细胞数量和松果体细胞体积。研究了两个年龄组，即6周龄和10月龄，以评估两种品系之间可能存在的与年龄相关的差异变化。两种品系的松果体在6周龄时具有相似的形态测量和形态学特征。这表明在6周龄时已经完成的松果体发育不受松果体细胞中褪黑素合成缺失的影响。后来，CBA品系的松果体因细胞肥大而体积增大。相比之下，在同一时期，C57BL/6J品系的松果体体积因松果体细胞减少而减小。通过光学显微镜分析的半薄切片显示，在所研究的任何年龄，这种细胞死亡在C57BL/6J品系中都不明显。因此，可以推测这些松果体中存在松果体细胞的逐渐减少。这些结果表明，松果体褪黑素可能在维持松果体细胞活力以及发育后松果体体积增加方面发挥作用。在未来关于这个腺体的研究中，应该考虑到在C57BL/6J松果体中观察到的异常模式。
