FUNCTIONAL DEGRADATION OF THE RABBIT SCIATIC-NERVE DURING NONCOMPRESSIVE SEGMENTAL ISCHEMIA

The purpose of this study was to evaluate functional degradation in a nerve with a local ischemic segment created without a direct compressi on effect, Ischemia of one segment of a rabbit sciatic nerve was induc ed by stripping the nerve's extrinsic blood supply along 15 cm. Blood flow of both in situ and ischemic nerves was quantitatively measured w ith radioactive microspheres in six serial segments in seven animals. The flow in one middle segment of the stripped nerve was significantly reduced to 0.1 ml/min per 100 g (p = 0.006). In another eight animals , both in situ and stripped nerves were metabolically challenged with repetitive stimuli (200 Hz). Conduction velocity and peak amplitude we re measured before stimuli, after 30 and 60 minutes of stimuli, and af ter a 30-minute recovery period. Conduction velocity was reduced in bo th nonischemic and stripped nerves during prolonged repetitive stimula tion. Peak amplitude was reduced slightly in the nonischemic group and markedly in the stripped group. Normal or higher values were seen aga in in both groups during the recovery period. It was demonstrated, the refore, that conduction propel ties of the nerve, especially amplitude , can de affected by localized ischemia in one segment.