Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2007
Sciatic nerve block with resiniferatoxin: an electron microscopic study of unmyelinated fibers in the rat.
Perineural administration of the naturally occurring vanilloids (capsaicin, resiniferatoxin [RTX]) produces selective nociceptive blockade. Studies using perineural vanilloids in high concentrations suggest that they can cause a degeneration of unmyelinated fibers. However, electron microscopic studies of local vanilloid toxicity produced conflicting outcomes. In the present study, we sought to determine whether RTX-induced reversible sciatic nerve block results in the degenerative changes of unmyelinated fibers. ⋯ The results of the study suggest that a selective and long-lasting sciatic nerve block (up to 2 wk) can be provided by RTX without any significant damage to the unmyelinated nerve fibers.