Kim S K, Allen E D
Research Service, Veterans Administration Medical Center, Ann Arbor, Michigan 48105.
Microsc Res Tech. 1994 Jun 15;28(3):243-53. doi: 10.1002/jemt.1070280308.
Various salivary glands in senescent humans and other animals have been examined extensively to characterize the structural and functional changes that occur during aging. Although a wide range of different structural changes, involving both the parenchymal and stromal tissues, have been described, it is unclear how any of these changes affects the function of the salivary glands. One major change in structure is the reduction in the volume of acini with a concomitant increase in the ductal volume. Despite this loss of functional acini, the salivary output and the contents seem to be unaltered, or minimally altered, due to aging. One consistent change observed in many salivary glands of aged animals is the decline in the rate of synthesis of proteins and their messenger RNA (mRNA). However, the salivary acinar cells from aged animals can synthesize secretory proteins at an elevated rate just as effectively as those from their younger counterparts in response to external stimuli, which are known to enhance the rate of protein synthesis. Thus, it appears that the salivary acinar cells, which remain structurally intact during aging, seem to retain their functional efficiency. Furthermore, these acinar cells, although reduced in number, are sufficient in quantity to carry out most of the salivary gland functions.
人们已经对衰老的人类和其他动物的各种唾液腺进行了广泛研究，以描述衰老过程中发生的结构和功能变化。尽管已经描述了广泛的不同结构变化，包括实质组织和间质组织，但尚不清楚这些变化中的任何一种如何影响唾液腺的功能。结构上的一个主要变化是腺泡体积减小，同时导管体积增加。尽管功能性腺泡减少，但由于衰老，唾液分泌量和成分似乎未改变或仅有轻微改变。在许多老年动物的唾液腺中观察到的一个一致变化是蛋白质及其信使核糖核酸（mRNA）合成速率的下降。然而，老年动物的唾液腺泡细胞在受到已知能提高蛋白质合成速率的外部刺激时，能够以与年轻动物的唾液腺泡细胞同样有效的速率合成分泌蛋白。因此，似乎在衰老过程中结构保持完整的唾液腺泡细胞似乎保留了它们的功能效率。此外，这些腺泡细胞虽然数量减少，但数量足以执行大部分唾液腺功能。
