Natural course of diabetic peripheral neuropathy in spontaneous-onset diabetic Chinese hamsters

We investigated metabolic and pathological changes in the peripheral nerve of the spontaneous-onset diabetic Chinese hamster. Electrophysiological examination revealed that the motor nerve conduction velocity was significantly decreased at 10 months and afterwards, however, the F-wave latency was significantly increased at 5 months and afterwards. Concerning sciatic nerve contents of sorbitol, myo- and scyllo-inositol, the content of sorbitol was not significantly increased at 5 months, but, myo- and scyllo-inositol were significantly decreased at 5 months and thereafter. At 10 and 15 months, however, sciatic nerve content of sorbitol was significantly increased. On morphological examination, loss of large myelinated fiber and reciprocal increase in degenerative fiber were also seen in sciatic nerve, but not in tibial nerve, at 5 months. At 15 months, these morphological changes were also found in the tibial as well as the sciatic nerve. Thus, we may hypothesize that F-wave latency is useful in the detection of initial diabetic neuropathy, and that the initial pathological changes in diabetic neuropathy of diabetic Chinese hamsters are predominantly found in the proximal site of peripheral nerves.