Yagihashi S, Tonosaki A, Yamada K, Kakizaki M, Goto Y
Tohoku J Exp Med. 1982 Sep;138(1):39-48. doi: 10.1620/tjem.138.39.
Function and structure of peripheral nerves in selectively-inbred spontaneously diabetic rats (SDR) were quantitatively examined in order to clarify the relationship between these two changes. Electrophysiologically, SDR showed a significant decrease in motor nerve conduction velocity of the tail by 2 months of age. Thereafter, the conduction velocity was constantly lower in SDR than in age-matched control rats. Morphometrical analysis of peripheral nerves from light and electron micrographs could not yield any definite structural differences, except for a reduction in caliber of unmyelinated axons, between 2 month-old and age-matched controls, whereas an endoneurial space was widened in 3 month-old SDR as compared with those of controls. In contrast, loss of myelinated nerve fibers, a reduction in nerve fiber size and axonal size were apparent in 6 month-old SDR. By freeze-replica studies, neither any qualitative changes of intramembrane faces nor any quantitative differences in the density of intramembranous particles of internodal myelin and Schwann cell membranes were detected in 2 month-old SDR when compared with those in controls. The results suggested that the delayed nerve conduction velocity was most related to diabetic dysmetabolism and independent of the structural changes of peripheral nerves being in the course of distal axonopathy.
为了阐明这两种变化之间的关系，对选择性近交自发性糖尿病大鼠（SDR）外周神经的功能和结构进行了定量检查。在电生理方面，2月龄时SDR的尾部运动神经传导速度显著降低。此后，SDR的传导速度一直低于年龄匹配的对照大鼠。对2月龄和年龄匹配对照大鼠的外周神经进行光镜和电镜形态计量分析，除无髓鞘轴突口径减小外，未发现任何明确的结构差异，而3月龄SDR的神经内膜间隙比对照大鼠增宽。相比之下，6月龄SDR出现有髓神经纤维丢失、神经纤维大小和轴突大小减小。通过冷冻复型研究，与对照大鼠相比，2月龄SDR的节间髓鞘和施万细胞膜的膜内面既未检测到任何定性变化，也未检测到膜内颗粒密度的任何定量差异。结果表明，神经传导速度延迟与糖尿病代谢紊乱关系最为密切，且与远端轴索性神经病过程中外周神经的结构变化无关。
