AN ANIMAL-MODEL OF CHRONIC ISCHEMIC NEUROPATHY WITH PROLIFERATIVE CHANGES OF NERVE MICROVESSEL WALL

In order to produce a model of ischemic neuropathy with neural microva scular alterations, sodium laurate was injected into a femoral artery and saline into the contralateral artery at the mid-thigh level in Spr ague-Dawley rats aged 11 weeks. In view of the dose-related findings, 0.3 mg sodium laurate dissolved in 0.1 ml saline was used for the main experiment. The laurate-injected leg showed paresis during the experi mental period. On day 1-7, various stages of Wallerian degeneration an d acute microvascular changes were found. At 1 month, regenerating mye linated nerve fibers (MNFs) were found at the central or total fascicu lar area mainly in the distal tibial nerve. Morphometric analyses sugg ested that MNFs other than regenerating fibers are atrophic ones. The proliferative changes of nutrient microvascular walls were striking. T he percent of closed epineurial microvessels was significantly larger on the laurate-injected sides and inversely associated with the diamet er of MNFs. At 7 months, the attenuation of MNFs was more prominent an d microvascular alterations were persistently observed. These patholog ical findings resemble those of chronic ischemic neuropathy including. diabetic neuropathy, suggesting that this neuropathy model might prov ide some valuable and useful clues for clarifying the pathogenesis of chronic ischemic neuropathy.