[Pathogenesis of peripheral neuropathy in streptozotocin-induced diabetes in rats]

Experimental diabetes rats was induced in rats by intraperitoneal streptozotocin. The changes of glucose, sorbitol, fructose and free myoinositol in diabetic sciatic nerve and plasma, the changes of enzyme activity of sciatic nerve in relation to glucose, lipid and protein metabolism were studied during 1, 2, 4, 6, 12 weeks after induction of diabetes. The structural changes of 6 and 12 week diabetic sciatic nerve were observed sequentially by light and electron microscopy during the course of 6 and 12 weeks. The results showed that glucose, sorbitol and fructose in blood and sciatic nerve were increased markedly, but free myo-inositol was normal in blood and decreased in sciatic nerve. The enzyme activity such as ICDH, MDH, LDH, alpha-GPDH all reduced, but the activity of sorbitol dehydrogenase increased. Various ultrastructural changes such as swollen unmyelinated fibers, swollen mitochondria in axon, degenerative changes of myelin sheath and atrophic axon were observed, but no changes was found by light microscopy.