Acta neuropathologica
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Acta neuropathologica · Jul 2001
Same axonal regeneration rate after different endoneurial response to intraneural glycerol and phenol injection.
Glycerol (an atoxic alcohol) and phenol (a toxic monohydroxybenzene) are currently used as neurolytic blocking agents to relieve pain or spasticity. In the present study we compared the endoneurial response of anhydrous glycerol and 7% phenol-aqua after intraneural injection into rat sciatic nerve, using electron microscopy and immunohistochemical stainings. Despite the wide use of these drugs, a systematic morphological study of their action has not been done. ⋯ The delayed invasion of macrophages after phenol injection may be due to occluded vessels or may be related to the denaturing effect of phenol on the proteins needed for macrophage attraction. Despite the rapid invasion of macrophages after glycerol injection axonal regeneration was delayed when compared to that seen after traumatic axotomy, but the axonal regeneration occurred at the same time in both experimental groups. Thus, the results suggest that after chemical axonotmesis the axonal regeneration rate is not dependent on the macrophage invasion rate alone and that other endoneurial changes also play a role.