Abstract
Abnormalities of endoneurial microvessels have been implicated in the pathogenesis of diabetic neuropathy. To investigate endoneurial microvascular abnormalities in relation to changes in nerve fibers, the tibial nerves of rats with chronic streptozotocin induced diabetes were exmined by light and electron microscopy with morphometric analysis.
Reduced mean myelinated fiber size and increased myelinated fiber density consistent with the data reported previously, were demonstrated in the diabetic rats. The vascular area, luminal area and basement membrane area of the endoneurial vessels were increased in some diabetic rats, although their mean values were not significantly different from the normal controls. In contrast, pericyte area was significantly reduced in diabetic rats. There was no evidence of occluded vascular lumens or endothelial proliferation in the diabetic rats. Although changes in the endoneurial microvessels were relatively modest in diabetic rats, compared with those found in human diabetic paients, the changes suggest that alterations in the microcirculation of peripheral nerves may play a role in the progression of diabetic neuropathy.
