大鼠坐骨神经超微结构的老年性变化

Ultrastructural changes of sciatic nerve in the aged rats

为了研究老年大鼠坐骨神经超微结构特点,随机取3月龄(成年组)和24月(老年组)龄正常SD大鼠各10只,用电镜观察两组间坐骨神经超微结构的差异。结果显示:老年组大鼠坐骨神经内有髓纤维的百分比、轴突间胶原纤维密度以及Schwann细胞胞质中脂褐质沉积密度均多于成年组(P<0.05);但无髓纤维之百分比少于成年组(P<0.05)。上述结果提示坐骨神经内的有髓纤维与无髓纤维百分比、轴突间胶原纤维密度以及Schwann细胞胞质中脂褐质沉积密度是衡量大鼠坐骨神经老化的形态标志之一。

To study the uhrastructural features of the sciatic nerve in the aged rats, 10 normal SD rats （3 month old, adult group）and 10 rats normal SD （24 month old, old group）were taken randomly. The ultrastructural features of the sciatic nerve in the 2 groups were measured under electron microscope. The results showed that the percentage of myelinated nerve fibers, density of collagen fibers among axons, and density of lipofusein in Sehwann cell in sciatic nerve of the old group were all larger than that in the adult group （ P 〈 0.05 ） ; while the percentage of unmyelinated nerve fibers in sciatic nerve in the old group was lower than that in the adult group （ P 〈 0. 05 ）. These results suggest that the percentage of myelinated and unmyelinated nerve fibers, density of collagen fibers among axons, density of lipofusein in Sehwann cell in the sciatic nerve might be used as uhrastruetrual features to identify the aging degree of rats＇ sciatic nerves.